1. Which of the following is the characteristic of the living thing?
A. have specific shape
B. have regular shape
C. have organized body
D. none of the above
2. Which of the followings includes in homeostasis?
a. To maintain the shaped of the body
b. To maintain the balance of the body
c. To maintain the temperature of the body
d. To keep the animal away from the body
3. Your hearts starts beating before seven month of your birth. The study of your body at this stage comes within:
(a) Morphology (b) Embryology (c) Anatomy (d) Histology
4. A doctor is studying the contraction and relaxation of a heart. He is studying:
(a) Morphology (b) Embryology (c) Anatomy (d) Histology
5. Study of different parts of eye is called
(a) Histology (b) Anatomy (c) Physiology (d) None of these
6. A biologist removes some bones of dinosaurs from a rock. He is studying: (a) Morphology (b) Paleontology (c) Ecology (d) None of these
7. Darwin sys, “man has formed from monkey”. He talked about
(a) Fossil (b) Evolution (c) Taxonomy (d) None of these
8. Kangaroo lives in Australia but buffaloes lives in Pakistan. The study of this distribution of animals is called
(a) Ecology (b) Environmental biology (c) Taxonomy (d) Zoogeography
9. The study of structure of molecule of starch is called:
(a) Molecular biology (b) Biochemistry (c) Morphology (d) None
10. The study of Amoeba comes with in the branch of biology:
(a) Taxonomy (b) Ecology (c) Microbiology (d) None
11. The study of affects of pollution comes within:
(a) Environmental biology (b) Taxonomy (c) Physiology (d) Genetics
12. The study of organisms living in lake is called:
(a) Marine biology (b) Taxonomy (c) Physiology (d) Fresh water biology
13. The study of amount salt, temperature etc of water of sea comes within: (a) Environmental biology (b) Taxonomy
(c) Marine biology (d) None of the above
14. The study of life cycle of plasmodium comes within:
(a) Parasitology (b) Taxonomy
(c) Physiology (d) None of the above
15. The grouping of men is:
(a) Human biology (b) Social biology
(c) Biotechnology (d) None of above
16. The use of yeast in banking industry, and use of bacteria for making yogurt from milk are studied in:
(a) Human biology (b) Social biology
(c) Biotechnology (d) None of above
17. A biologist studies all structure and functions of different parts of a man. His work is included in branch of biology called:
(a) Human biology (b) Social biology
(c) Biotechnology (d) None of above
18. Biological organization means:
a. Study of different organisms
b. Study of different branches of biology
c. Study of All the subjects of sciences
d. Study of biology at different levels
19. Trace elements are those:
a.Which are necessary for the organisms
Which are present in a very small quantity in the body
Which are required in small quantity in the body.
Which do not require to body.
20. Common bio elements are:
Calcium, phosphorus and carbon
Nitrogen, oxygen and hydrogen
Calcium, copper and carbon
(a) and (b)
21. Protoplasm is a:
(a) second name of cell (b) second name of cytoplasm
(c) second name of Nucleolus(d) (b) and (c)
22. Bioelements are those elements:
Which are eaten by the organisms
Which are formed within the organisms
Which are used in the chemical compounds in the organisms
Which are released by the organisms
23. Which statement is not correct about biosphere:
(a) It is present on the earth (b) It is present in the oceans
(c) It is present in the river (d) It is present in the space.
24. Ecosystem is composed of:
(a) a community (b) a population
(c) a species (d) none of the above
25. Which of the followings is an organ system?
(a) oesophagus (b) Stomach
(c) intestine (d) All (a) and (c)
26. Which one of the followings is an organ?
(a) Cornea (b) Retina
(c) Eye (d) Eye muscles
27. Which of the followings is a tissue?
(a) Heart (b) stomach
(c) bone (d) Liver

28. Skin is:
(a) an organ (b) a tissue
(c) an organ system (d) None of all
29. ATP is a nucleotide. It is a:
(a) Micromolecules (b) Macromolecule
(c) Microelement (d) Microelement
30. Carbon dioxide is a compound of carbon. It is:
(a) an inorganic compound (b) an organic compound
(c) Both (a) and (b) (d) none of the above
31. Nucleus is:
(a) an organelles (b) Protoplasm
(c) cytoplasm (d) None of the above
32. A prokaryotic cell: has well defined nucleus is without nucleus and DNA is without nucleus but DNA is present
None of above
33. A eukaryotic cell:
(a) Without well defined nucleus (b) is without nucleus and DNA
(c) is with nucleus but DNA is absent(d) has both nucleus and DNA
34. Number of persons living in Multan is called
(a) Population of Multan (b) Community of Multan
(c) Ecosystem of Multan (d) None of above
35. Community of Lahore includes:
All the humans living in Lahore
All the organisms living in Lahore
All the animals living in Lahore
All the plants in Lahore.
36. Gene frequency mean:
Number of genes present in an organism
Number of genes present in a population
Number of genes present in a community
None of above
37. An island in an sea is a:
(a) a population (b) Simple community
(c) complex community (d) None of the above
38. A dog kills a rabbit
(a) Rabbit is a predator (b) Dog is a prey
(c) Dog is a predator (d) Both are predator
39. Which one of the following is a biome:
(a) An ocean (b) A river
(c) Conifer forest (d) A garden
40. The fossils present in the older layer of a rock could be:
Ancestor of the fossils present in the younger sediments
Have equal age as that of younger sediments
Offspring of the younger sediment
None of the above
41. The older sediments in a rock have:
Smaller amount of radioactive substance than the younger one
Larger amount of radioactive substance than the younger one
Equal amount of radioactive substance with the younger one
Do not have radioactive substance at all
42. We are now living in:
(a) Proterozoic era (b) Paleozoic era
(c) Mesozoic era (d) Coenozoic era

43. Phyletic lineage means:
(a) 2000 Million years ago (b) 3000 Million years age
(c) 4000 Million years age (d) 5000 Million years age
44. Phyletic lineage means:
All the organisms have same ancestor and they show similarities.
All the organisms have different ancestor but they show certain
Similarities
All the organisms have same ancestor but they do not show
Similarities
None of the above
45. Total number of species on the earth is:
(a) 2.5 Millions (b) 2 Millions
(c) 3.5 Millions (d) 1.5 Millions
46. The most abundant group on the earth is:
(a) Mammals (b) Birds
(c) Insects (d) Reptiles
47. Which group of the followings has lowest number of species?
(a) Vascular plants (b) Animals
(c) Insects (d) Algae, protozoa and Prokaryotes
48. Measurement of temperature is:
(a) Quantitative (b) Qualitative observation
(c) None of the above
49. Mammals have hairs on their bodies. Dog also have hairs on its body. So dog is also a mammal. It is:
(a) Deductive reasoning (b) Inductive reasoning
(c) None of the above
50. Inductive reason moves from:
(a) Known towards unknown (b) Unknown towards known
(c) Known towards known (d) none of the above

Answers check your ability by matching your choice to these
1. (c) 2. (c) 3. (b) 4. (d) 5. (b) 6. (b)

7. (b) 8. (d) 9. (a) 10.(c) 11.(a) 12.(d)

13.(c) 14.(a) 15.(b) 16.(c) 17.(a) 18.(d)

19.(b) 20.(d) 21.(d) 22.(c) 23.(d) 24.(d)

25.(d) 26.(c) 27.(c) 28.(a) 29.(a) 30.(a)

31.(a) 32.(c) 33.(d) 34.(a) 35.(b) 36.(b)

37.(b) 38.(c) 39.(c) 40.(a) 41.(a) 42.(d)

43.(b) 44.(a) 45.(a) 46.(c) 47.(d) 48.(a)

49.(a) 50.(b)

1. Sacculina belongs to __________.
(Arthropoda, Nematoda, Annelida)
2. The locomotory organs of sea star are __________.
(Parapoda, Setae, Tube-feet)
3. Prehensile tail is present in __________.
(El fish, Sea horse, Wall lizard)
4. Ascaris is parasite in __________.
(Stomach, Intestine, Liver)
5. Pineal glands secrete __________.
(Thyroxin, Melatonin, Esterogen)
6. Bicuspid valve lies between __________.
(Righ Auricle and right Ventricle, Left Auricle and Ventricle, Right Auricle and Left Ventricle)
7. Monocytes and __________ are agrantocytes.
(Neutrophils, Colgi body, Lymhocytes)
8. Glucose is converted during glycolysis into __________.
(Urea, Uric acid, Pyruvic Acid)
9. Liver-fluke lives in __________.
(Liver, Gall bladder, Bile duct)
10. The class Ophiurodiea belongs to the phylum __________.
(Echimedermate, Aschelminthes, Urochordate)
11. The skeleton of a dog-fish is made of __________.
(Bones, Cartilages, Muscles)
12. The prehensile tail is present in __________.
(Eel fish, Sea horse, Bat)
13. Rods and cones are present in the eye of a __________.
(Cockroach, Human, Leech)
14. Each villus is provided with lymph vessels called __________.
(Venules, Lacteals, Veins)
15. The organs of excretion in cockroach are called __________.
(Nephridia, Malpighian Tubules, Gills)
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16. Ductless glands are known as __________.
(Endocrine Glands, Digestive Glands, Milk Glands)
17. Leishmania is a parasite of __________.
(Intestine, Blood, Bile duct)
18. Each villus is provided with lymph vessels called __________.
(Arteris, lacteals, Venules)
19. Throxin hormone is secreted by __________.
(Thyroid glands, Pituitary Glands, Adrenal glands)
20. The body of __________ is covered by epidermal scales __________.
(Amphibians, Reptiles, Birds)
21. Water vascular system is present in __________.
(Star Fish, Sponge, Leech)
22. The free swimming larva of liver fluke is __________.
(Trochophore, Miracidium, Glochidium)
23. Tape worms are parasites living in __________.
(Intestine, Muscles, Lungs)
24. The Coelenterates bear stinging cells called __________.
(Sporocysts, Conocysts, Nematocysts)

Read more: Zoology MCQS XI Karachi Board MCQs http://www.friendsmania.net/forum/1st-year-biology-notes/20543.htm#ixzz2JcLnfaso
1. Salivary amylase digests carbohydrates in __________ medium.

2. The life-cycle of Plasmodium in mosquito discovered by __________.

3. The larva of Balanoglossus (acron worm( is called __________.

4. Legless amphibians are included in class __________.

5. Flame cells are found in __________.

6. Nephridia are the excretory organs of __________.

7. Butterfly exhibits __________ metamorphosis.

8. Euplectella belongs to __________.

9. Termites live in __________ colony.

10. Reptiles, birds and mammals are collectively called __________.

11. In sponges the spongocoel is lined with __________.

12. Cyclops is an example of the phylum __________.

13. In 1880 A.D Lavern discovered a protozoan parasite in the __________ of a malaria patient.

14. A protozoan parasite __________ causes human dysentery.

15. The organs of excretion in insects are __________.

16. There are five pairs of gills in __________ class of fish.

17. Saccutina a parasite of __________.

18. Thyroxine contains __________.

19. The larva of polychaete is called __________.

20. Elephantiasis is caused by __________.

21. The cnidoblasts are present in the phylum __________.

22. Rock mountain spotted fever is transmitted by cetain __________.

23. The end product of carbohydrate digestion is __________.

24. The contractile vacuole performs the function of __________.

25. Scyphistoma is the larval form of __________.

26. The study of the functions of the organs is known as __________.

27. Nearly 200 years ago the mammals evolved from __________

28. __________ is the largest gland.

29. Mantle is the characteristic of the phylum __________.

30. Class __________ has the largest number of species of the whole animal kingdom.

31. Kangaroo belongs to the sub class __________.

32. The locomotory organs of polychaets are __________.

33. Non-nucleated R.B.C are found in blood of __________.

34. The fore-brain consists of Telencephalon and __________.

35. Bat is a flying __________.

36. Phylum __________ and __________ include marine animals.

37. __________ is the unit of excretory organs.

38. Respiration is the process of __________.

39. __________ is an example of Polymorphism.

40. Book lungs are the respiratory organs of __________.

41. In insects the excretion is performed by __________.

42. Class Agnatha is also called __________.

43. Cortisone hormone is seceted by __________ gland.

44. Swim bladder is found in the class __________.

45. The larva of Neries is called __________.

46. Spider belongs to the class __________.

47. The heart of a bird is divided into __________ chambers.

48. Cercaria is the larva of __________.

49. The dendrons carry inpulse towards __________.

50. The outer layer of the wall of the eyeball is known as __________.

51. Flame cells are the organs of __________.

52. Balano glosus is included in the Phylum __________.

53. The meaning of malaria is __________.

54. The study of the internal structure of an organism is called __________.

55. Flame cells are excretory organs of phylum __________.

56. Trypanosome is a blood parasite.

57. The dissimilar teeth in mammals are called __________.

58. The respiratory organs of insects are __________.

59. The skeletal parts of sponges are called __________.

60. Nematocysts are found in the phylum __________.

Read more: Zoology Fill in the Blanks XI Karachi Board http://www.friendsmania.net/forum/1st-year-biology-notes/20542.htm#ixzz2JcMPkLwg
1 GENERAL CHARACTERS
* 2 1. NOTOCHORD
* 3 2. DORSAL HOLLOW NERVOUS SYSTEM
* 4 3. GILL CLEFTS
* 5 4. PHA-RYNGEAL POUCHES
* 6 OTHER FEATURES
* 7 CLASSIFICATION OF PHYLUM CHORDATA
* 8 1. GROUP ACRANIATA (PROTOCHORDATA)
* 9 A) SUB-PHYLUM UROCHORDATA (NOTOCHORD IN TAIL)
* 10 B) SUB-PHYLUM CEPHALOCHORDATA (NOTOCHORD FROM HEAD TO TAIL)
* 11 2. GROUP CRANIATA (VERTEBRATA)
* 12 A) SUB-PHYLUM AGNATHA (MOUTH WITHOUT JAWS)
* 13 B) SUB-PHYLUM GNATHOSTOMATA (MOUTH WITH JAWS)
* 14 I) SUPER CLASS PISCES (FISHES)
* 15 LUNG FISHES
* 16 II) SUPER CLASS TETRAPODA
* 17 A) CLASS AMPHIBIA
* 18 B) CLASS REPTILIA
* 19 C) CLASS AVES (BIRDS)
* 20 CHARACTERS OF CLASS AVES
* 21 SUB-CLASSES OF AVES
* 22 D) CLASS MAMMALIA
* 23 CLASSIFICATION OF CLASS MAMMALIA

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Class XI, BIOLOGY, "Enzymes"
ENZYMES(BIO-CATALYSTS) Enzymes are bio-catalyst which speed up the chemical reactions by lowering “Energy of activation”.
ENERGY OF ACTIVATION
Amount of energy which is required to start a chemical reaction. OR Energy required to break a (particular covalent) bond present in reactant.
NOMENCLATURE OF ENZYMES
Enzyme is a Greek word means-En(in) and Zyme(yeast).
DISCOVERY OF ENZYME
Term “Enzyme” was coined by F.W Kuhne in 1978.
NATURE OF ENZYME
Almost all enzymes are protein in nature except few which are nitrogenous acids like RNA-DNA(Ribozymes). Ribozymes catalyze reactions in genetic informations.
CHARACTERISTICS OF ENZYMES
Protein in nature and are formed by living cells.
May be intracellular or extra cellular.
Remains unchanged during and after the reaction.
Speed up the rate of reaction by decreasing energy of action.
Specific in their nature.
Heat sensitive and act on particular (optimum) temp.
Each has specific substrate pH for its activity.
Action can be alter by activators and inhibitors.
CLASSIFICATION OF ENZYME (ON THE BASIS OF STRUCTURE)
Pure or Simple Enzyme consist of only protein (e.g.Amylase and Pepsin) Conjugated or Holoenzymes: May contain a non-protein part “Prosthetic group” as well (e.g. Phosphatase and Peptidase)
Holoenzyme = Apoenzyme + Prosthetic group
…………….(Protein part)….(Non-protein part)
CLASSIFICATION OF ENZYME (ON THE BASIS OF FUNCTIONS)
(1) OXIDOREDUCTASE
Catalyze reactions in which one substrate is oxidized while other is reduced. Sub classes are:
Dehydrogenases(convert single bond to double bond)
Oxidases (use oxygen as oxidant)
Peroxidases (use H202 as oxidant)
Hydroxylases (introduce hydroxyl group)
Oxygenases (introduce mol. Oxygen in place of double bond).
(2) TRANSFERASES
Transfer one carbon group (e.g. methyl) from one substrate to another substrate.
(3) HYDROLASES
Catalyze hydrolytic cleavage of C-O, C-N, C-C and P-O bonds and other single bonds (e.g. Peptidases, Esterases, Glycosidases and Phosphatidases).
(4) LYASES
Catalyze Elimination reactions to form double bond and reversible reaction by adding groups across double bond (e.g. Decarboxlases, Aldolases and Dehydratases).
(5) ISOMERASES
They alter the structure but not the atomic composition by moving a group from one position to another in one molecule (e.g. Epimerases, Mutases).
(6) LIGASES
Catalyze reaction in which two molecules are joined. They are also known as synthtases.
ROLE OF ENZYME
The enzyme react with (energy rich or energy poor) molecules and forms an intermediate complex that breaks into,
(a) Product
(b) Enzyme
(i) Substrate + Enzyme = Complex
(ii) Complex = Product + Enzyme
The equilibrium is achieved if the ratio of conc of reactants (substrate) and product remains same.
Rate of reaction 1/µ Energy of activation
MODE OF ACTION OF ENZYMES
1- The action of enzyme depends on its chemical structure. A typical enzyme molecule, has “3D” structure.
2- Has depression or pit for substrate (to fit in) known as “Active site”.
3- Any other site other than active site is called “Allosteric site”
There are two theories in respect of enzyme action, which are as follows.
LOCK AND KEY MODEL
Proposed by Fischer (1898) and modified by Paul Filder and D.D Woods according to this model,
The active site of enzyme has distinct shape.
It allows few substrate to fit in (like a particular lock allows particular key to fit in)
Enzyme breaks substrate to product
FIGURE From Text Book 3.3 page #46 (The cycle of Enzyme – substrate Interaction)
INDUCE FIT MODEL
Proposed by koshland (1959), it states that
Enzyme binds with a substrate
This binding induce changes in enzyme structure
Due to this change enzyme acts and forms product
FACTORS AFFECTING ENZYME ACTIVITY
The activity of enzymes depend on following factors,
1. SUBSTRATE CONCENTRATION
Increases with increase in substrate concentration (up to a limit)
At very high concentration, activity again decreases due to saturation of enzyme with substrate and saturation of product i.e. higher concentration of product.
2. TEMPERATURE
Increases with in temperature(up to limits)
Maximum activity at optimum temperature.
Highly active at 37˚C and destroyed at 100˚C
At 0˚C minimum activity.
3. PH
Enzymes are pH specific i.e. work in specific pH(because of protein can act both in acidic and basic medium.
4. WATER
Enzyme activity is usually maximum (up to limits) but decrease after limits (dilution of enzyme)
5. RADIATIONS
Enzymes become inactive due to radiations (including Alpha, Beta, Gamma rays).
6. CO-ENZYME AND ACTIVATORS
Induce the enzyme activity.
THINGS TO BE REMEMBER
INHIBITORS
Substances which decreases the activity of enzymes.
COMPETITIVE INHIBITORS
Inhibitor molecules which resemble the normal substrate molecule and compete for admission into the active site. They block the substrate from entering active site.
NON-COMPETITIVE INHIBITORS
Inhibitors bind to a part of the enzymes away from the active site (Allosteric site). This binding cause change in the enzyme molecule shape and decrease in enzyme activity.
FEED BACK INHIBITION
Common biological control mechanism of brain in order to regulate enzyme activity.
PROSTHETIC GROUP
Non-protein part of enzyme (Co-enzyme or Co-factor)
CO-ENZYME
When prosthetic group consist of organic molecules (like FAD/NAD)
CO-FACTORS/ACTIVATORS
When prosthetic group consist of inorganic molecules (like Ca++, Na+ etc).
APOENZYME

Phylum Porifera (Sponges)

MAIN CHARACTERISTICS
Animals of this phylum show following important characters.
NATURE
Most simple multicellular organisms. From evolutionary point of view they occupy a position between protozoa and true metazoa
HABIT AND HABITAT
Mostly marine but few in fresh water habitat.
They are sessile, living attached to rocks, coral and other hard surfaces
SHAPE AND STRUCTURE
Their shape may be cylindrical, branching, globular, flat, bell shaped or cup shaped.
Some are dull in colour and most are brightly coloured.
The body is perforated by pores and canals.
MICROSCOPIC STRUCTURE
Most of sponges contain following types of cell:
(A) PINACOCYTES
Forming the epidermis.
(B) POROCYTES
Form pores of the body wall
(C) CHOANOCYTES
These are flagellated cells, form the internal lining of the body. These cells are strikingly similar to the choano flagellates.
Much of the body is composed of jelly like matrix containing a skeleton made of Protein, CaCO3 or silica.
Sponges are organized on cellular level, instead of a single cell carring on all the life activities.
Sponges show cellular differentiation but little or no coordination of cells to form tissues.
They usually have an endoskeleton of separate spicules.
They do not posses a head, an interior end, a mouth or gut cavity.
They are sedentary organisms ranging in size from 1 to 200cm.
DIGESTION
Digestion takes place with in the cell. (Intracellular)
PROCESS OF FEEDING, EXCRETION AND RESPIRATION
Sponges feed by filtering out bacteria and fine particles of organic matter from water.
The flagella of “Choanocytes” beat and create a current of water.
The water current also helps in respiration, removal of waste products and dispersal of gametes.
REPRODUCTION
Reproduction is of both type asexual and sexual
Asexual reproduction is by means of “Buds” and “Gemmules formation”.
Sexual reproduction is by means of sperm and ova.
All sponges appear to be diploid and have the usual metazoan process of “Oogenesis” and “Spermatogenesis”.
The eggs retained just beneath the choanocytes where they are fertilized by sperm from another sponge brought in with the current of water.
Fertilization is internal.
LARVA
After cleavage, the larva escape from the parent to the open sea as a free swimming “Amphiblastula larva”.
It finally becomes attached to the bottom by its anterior end.
Reproduction is also by fragmentation.
BODY CAVITY
Body cavity is known as “Spongocoel”.
EXAMPLES
Common examples are
1. Sycon
2. Euplectella
3. Euspongia
Phylum Aschelminthes (Nematoda/Round worm)

MAIN CHARACTERS

HABIT AND HABITAT
Nematoda have a very wide distribution and they seem to have mastered almost every habitat.
Free living nematodes are found in the sea, fresh water or in the soil in all kinds of environment.
There are also many Parasitic nematodes found in all groups of Plants and animals.
The Saprophagous species live in decomposing plant and animal bodies and in rotting fruits.
NATURE
They have a bilaterally symmetrical, cylindrical body, glistening smooth surface. They are triploblastic.
EXTERNAL FEATURES
They show no trace of segmentation.
Most of the free living nematodes are less then a millimeter length.
Some of the parasitic species attain a length of several meters e.g. Guinea worm (Dracunculus medinensis).
They are usually long, round, tapered at both ends showing very little morphological diversity from species to species.
The mouth of nematodes is modified for various modes of feeding such as cutting, tearing, piercing and sucking fluids from the host.
Body is covered by cuticle, which moults only during the period of growth.
INTERNAL FEATURES
The organs are packed in parenchyma when young, but later on it disappears in adult. So that organs lie in a fluid filled cavity. This cavity is termed as PSEUDOCOEL and it has not peritoneum.
Muscles are only longitudinal.
Excretory system has no flame cells.
Alimentary canal is straight with ectodermal fore and hind gut and an endodermal mid gut.
REPRODUCTION
Sexes are generally separate.
Gonades are tubular and continues with their ducts.
Female organs are usually paired and open by vulva.
Male organs are single and open into a cloaca.
The life cycle of Parasitic species involves one, two or more hosts
EXAMPLES
Ascaris (Round worms), Hookworms and Thread worms etc.
Posted by Kawish Hass
Phylum Annelida (Segmented worms)
MAIN CHARACTERS
NATURE
Annelida are triploblastic, symmetrical, coelomata and segmented metozoa.
HABIT AND HABITAT
Annelida are mostly aquatic, marine or fresh water, burrowing or living in tubes, some free living forms.
EXTERNAL FEATURES
The most important feature of annelida is their metameric segmentation. (External segmentation)
Segmentation is indicated externally by circular constrictions or grooves on the body wall.
Outer covering of the body is cuticle secreted by the underlying epidermis.
Appendages, when present are unjointed.
Locomotory organs are segmentally arranged, paired setae or chaetae.
INTERNAL FEATURES
Body wall is contractile, consists of an outer epidermis, circular and longitudinal muscles.
The gut, longitudinal blood vessels and the nerve cord extend throughout the body length, whereas other structures are repeated in each segment.
Important character of annelida is the development of series of coelomic compartments in their body between the gut and the body wall.
The Coelom is a cavity, which develop within the mesoderm and is lined by mesodermal cells.
Segmented musculature plays an important part in locomotion of Annelids.
SYSTEMS OF BODY
Alimentary canal is tube like extending straight from mouth to anus.
Respiration through general body surface, by gills in some forms.
Blood vascular system is closed type.
Blood is red due to haemoglobin.
Excretory organs are Nephridia usually one pair in each segment.
Nervous system consists of dorsal brain and longitudinal ventral nerve cord.
Sexes may be united or separate.
Development is direct when sexes are united and indirect when sexes are separate.
EXAMPLES
Nereis, Earthworm and Leeches etc.

CLASSIFICATION OF PHYLUM ANNELIDA
Phylum Annelida is divided into four classes:
1. Polychaeta
2. Oligochaeta
3. Hirudinea
4. Archiannelida
1.POLYCHAETA
LOCOMOTORY ORGANS
The Polychaetes possess paired parapodia functioning as locomotry appendages, are present only in the class Polychaeta.
PROSTOMIUM
Usually there is a distinct head or Prostomium bearing sensory and feeding appendages.
MODE OF LIFE
The Polychaetes may be carnivorous, scavengers, or filter feeders.
REPRODUCTION
The sexes are separate and fertilization of eggs takes place outside body. Their free swimming larva is called Trochophore.
RESPIRATION
The respiration takes place through the body surface in many but in some gills may be present as respiratory organs.
EXAMPLES
Some well-known examples of marine polychaetes are Nereis, Arenicola and Sabella. Nereis lives beneath stones and in crakes of rocks.
2.CLASS OLIGOCHAETA
LOCOMOTORY ORGANS
The Oligochaetes possess fewer numbers of Setae as compared to the Polychaetes. The setae help the earth worms in crawling.
SENSE ORGANS
There anterior end lacks eyes, or sensory appendages.
CLITELLUM
At sexual maturity, all of the oligochaetes develop in several segment, glandular epithelium, called clitellum.
MODE OF LIFE
Oligochaetes live either in fresh water or on land.
There is no free swimming larval stage in their development
Majority of oligochaetes are scavengers, feeding on decomposing organic matter.
Some fresh water species feed on algae.
Burrowers like earth worm ingest a large quantity of soil, digest the organic matter and the living fauna.
RESPIRATION
Respiration takes place through their general body surface. Some aquatic species possess anal gills.
ECONOMIC IMPORTANCE
Earthworms increase the fertility of soil by physically over turning it. They ingest the soil, break it down and deposit it in the form of casts. The over turned soil is relatively in proportions of total nitrogen, organic carbon, calcium, magnesium and phosphorus.
3.CLASS HIRUDINEA
BODY SEGMENTS
Unlike polychaetes and oligochaetes, the number of body segment in leeches is fixed at 34.
SUCKERS
The anterior and posterior body segments are fused to form suckers.
LOCOMOTION
Leeches either swim or crawl.
RESPIRATION
Respiration generally takes place through the body surface. Leaf like gills may be present.
PARASITIC NATURE
Most leeches feed by sucking blood of aquatic invertebrates and vertebrates.
4.ARCHIANNELIDA
It is a small group of marine worms.
They are not segmented externally and don’t have bristles.
They live in the sea and show annelid characteristics to a minor extent.
Their development is also characterized by Trochophore Larva.
EXAMPLES
Nerilla
Dinophilus

Phylum Arthropoda (Jointed Appendages Animals)

MAIN CHARACTERS
Arthropoda is the largest Phylum of the animal kingdom including 10, 00000 species of different types of animals.
The word Arthropods is derived from Greek Arthos – Jointed and Podos – Foot.
HABIT AND HABITAT
Arthropodes have undergone an adaptive radiation for aerial, aquatic, terrestrial and parasitic environment. They are widely distributed in each and every place of the world.
NATURE
Arthropoda are “bilaterally symmetrical,” metamerically segmented metazoa.
EXTERNAL FEATURES
Their body is covered by an exo-skeleton of “chitin” and protein.
They possess paired jointed appendages.
Their metamers are not alike but are specialized and their number is generally fixed.
The head is well developed.
INTERNAL FEATURES
Musculature is not continues but comprises separates striped muscles.
The coelomic space in Arthropods is occupied by the blood vascular system and is thus called “Haemocoel.”
Digestive tract is complete; mouth and anus lie at the opposite end of the body.
Circulatory system is open with dorsal heart and arteries but without capillaries.
Respiration through general body surface, by gills in aquatic forms, trachea or book lungs in terrestrial forms.
Excretion by “Malpighian tubules” or Coelomoducts.
Sexes are generally separate and sexual dimorphism is often exhibited by several forms.
Fertilization is internal.
Development is usually indirect through the larval stage.
Nervous system of arthropods is quite similar to that of annelids and consists of dorsal anterior brain and a double ventral nerve cord.
CLASSIFICATION OF ARTHROPODA
Phylum Arthropoda is divided into following five classes:
1. CLASS MEROSTOMATA
Almost all members of the class Merostomata are extinct. The only living merostomes, the king Crabs have survived.
The animals are horse-shoe shaped.
The long spike like tail that extends, posteriorly is used in locomotion. It is called “Telson.”
They feed on mollusks, worms and other invertebrates that they find on the ocean floor.
King Crabs a hors-shoe crabs have a tough “Carapace” jointed to a smaller abdomen.
E.g:Limulus Polyphemus (King Crab).
2. CLASS ARACHNIDA
This class includes spiders, scorpions, mites, ticks and many other terrestrial arthropods.
The Arachnid body consists of a cephalothorax and abdomen.
Cephalothorax is comprised of fused head and thorax.
Arachnids have six pairs of jointed appendages.
Most Archnids are carnivorous and prey upon insects and other small arthropods.
Respiration in archnids takes place either by trachea or book lungs or by both.
They are mainly terrestrial arthropods.
They have no antenna.
Cephalothorax is non-segmented.
E.g: Scorpions, Ticks & Mites, Spiders
3. CLASS CRUSTACEA
They live both in marine and fresh waters.
A few are terrestrial.
Crustaceans are unique among arthropods in possessing two pairs of antenna.
They always have one pair of mandibles and two pairs of maxillae around the mouth.
Mandibles are usually adapted for biting and chewing. Maxillae are used for holding the food.
Their body is divided into three distinct parts, i.e. the head, thorax and abdomen.
Respiration usually takes place through gills associated with appendages.
The sexes are usually separate and the reproduction is sexual.
The thoracic and abdominal appendages may be variously modified for walking, swimming, feeding, respiration or as accessory reproductive structures.
E.g: Sacculina (Parasitic Crustacean), Astacus (Cray-fish), Prawns, Shrimps, Lobsters and Crabs etc.
4. CLASS MYRIAPODA
All the animals are terrestrial.
Their body is divided into a head and an elongated trunk with many segments.
Each segment bears one or two pairs of legs.
They are carnivorous /herbivorous.
Eyes may present or absent.
E.g: Millipedes and Centipedes etc.
5. CLASS INSECTA (HEXAPODA)
Insecta is the largest class of the animal kingdom.
HABIT AND HABITAT
In their adaptive radiation, approximately a 8,50,000 species of insecta have occupied all types of terrestrial habitat.
Some live in fresh water, however one small group is marine.
NATURE AND ADAPTATIONS
The great success of insects can be attributed partly to the development of flight in them.
Flight has provided them the great capacity of dispersal, access to food sources, and favourable habitat and escape from enemies.
Corresponding to their number of species, there exists a huge variation in their structural and biological adaptations.
EXTERNAL FEATURES
All insects have their body divided into three well-defined regions i.e. the head, thorax and abdomen.
There is always a pair of antenna on the head.
The thorax always consists of three segments:
(a) Prothorax
(b) Mesothorax
(c) Metathorax
Each thoracic segment bears a pair of legs.
Head consists of six fused segments and a pair of compound eyes and mouth parts.
Abdomen comprises 7-11 segments and devoid of appendages.
MOUTH PARTS
The feeding appendages consists of three pairs:
(a) Mandibles
(b) First Pair of Maxilla
(c) Second Pair of Maxilla
The second pair of maxillae have fused together to form the “LABIUM,” or lower lip
The upper lip is formed by the projections head and is called the “LABRUM.’
Types:- The mouth appendages have been greatly modified to form five basic types of pattern:
(i) Biting
(ii) Chewing
(iii) Piercing
(iv) Sucking
(v) Siphoning or Sponging
INTERNAL FEATURES
Heart is elongated, tubular and divided into chambers situated in the abdomen.
Excretion takes place through “Malpighian tubules.”
Liver is absent but salivary glands are usually present.
Respiration is by “TRACHEA”. External gills may be present as accessory respiratory organs in some aquatic insects.
REPRODUCTION
Reproduction is sexual in most insects. However it takes place parthenogenetically i.e. eggs developing without being fertilized by sperms in a number of insects e.g: Aphids and Termites etc.
METAMORPHOSIS
The development of insects after hatching from egg into adult stage involves considerable growth and in some cases drastic morphological changes.
The entire post-hatching development is termed as “Metamorphosis.”
(A) INCOMPLETE METAMORPHOSIS
In some insects the immature form that hatch from the egg are essentially similar in shape to their adults, but are smaller in size, lack wings and reproductive organs
They attain adult characters after some growth period. This type of metamorphosis is called “Incomplete Metamorphosis.”
Three stages are Egg → Nymph → Adult.
For example Cockroach, Grasshopper, Bugs etc.
(B) COMPLETE METAMORPHOSIS
In this type the animal shows following stages during its complete development: Egg → Larva → Pupa → Adult.
For example Mosquito, Butter fly, House fly etc.
ECONOMIC IMPORTANCE OF INSECTS
Insects are of very great importance to man.
BENEFICIAL INSECTS
1. Apis, the honey bees produce honey and also give wax.
2. Insects bring about the cross-pollination.
3. Bombyx and Eupterote are silk-moths and produce silk.
4. The larvae of Lucilla and Pharmia are used in wound healing of bones.
5. Some insects feed upon and destroy harmful insects.
6. Some insects are Scavengers
HARMFUL INSECTS
1. Many types of mosquitoes, flies, fleas, lice and bugs transmit diseases to man and animals.
2. Human food is spoiled by cockroaches, ants and flies.
3. Tinea and Teniola are cloth-moths and destroy cloths.
4. Tenebrio is mealworm. They eat meal, flour and grains.
5. Lepisma destroy the books.
6. Termites destroy books and wood.
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Class XI, BIOLOGY, "Phylum Echinodermata"
Phylum Echinodermata
GENERAL CHARACTERS
HABIT AND HABITAT
The Echinodermates are exclusively marine including the largest invertebrate “Giant Squids.”
EXTERNAL FEATURES
Symmetry usually radial, nearly always pentamerous.
Body shape is rounded to cylindrical or star like.
Surface of the body is rough.
Body wall consists of an outer epidermis, a middle dermis and inner lining of peritoneum.
INTERNAL FEATURES
Endoskeleton consists of closely fitted plates forming shell usually called “THECA,” may be composed of separate small “OSSICLES.”
Coelom is spacious, lined by peritoneum and occupied mainly by digestive and reproductive systems.
Presence of “Water Vascular System” is most characteristic feature.
Alimentary tract is usually coiled.
Circulatory or Haemal or blood lacunar system is typically present.
Excretory system is wanting.
Nervous system is primitive, consists of ganglionated nerve cord.
Sense organs are poorly developed.
Sexes are usually separate.
Reproduction is usually sexual, fertilization is external.
WATER CANAL SYSTEM
Water canal system is unique in possessing an internal closed system of canals containing a watery fluid.
REGENERATION
Regeneration of lost part is common
IMPORTANCE OF WATER CANAL SYSTEM
These canals are provided with tubular protrusions called “Tube Feet,” which serve a number of functions like locomotion, anchoring to hard surfaces, grabbing the prey, diverting food particles towards mouth and in some cases also respiration. The watery fluid is drawn from the surrounding water through a perforated disc called the “Madreporite.”
EXAMPLE
Star Fish, Brittle stars, Sea urchins, Sea-cucumbers, Sea-Dollar, Sea-lilies and Feather stars.
LARVA
Bipinnaria larva

Class XI, BIOLOGY, "Phylum Hemichordata"
GENERAL CHARACTERS
It is a small group of animals, which include about 90 species.
They are soft-bodied animals, which usually live in shallow “U” shaped burrows in the sandy or muddy sea bottom.
EXTERNAL FEATURES
They are cylindrical or vase shaped animals, bilaterally symmetrical and lack any segmentation.
They may be solitary or colonial and usually range between a few millimeter and 250 cm in length.
Sexes are separate in hemichordates.
INTERNAL FEATURES
Circulatory system is open and coelom is divided into three chambers.
A dorsal and a ventral nerve cord are present.
LARVA
Tornaria larva
EXAMPLE
Phylum Platyhelminthes (Flat worms)

MAIN CHARACTERS
HABIT AND HABITAT
Animals are mostly Parasitic in habitat and found in other higher animals. But some animals are also free living.
NATURE
They are triploblastic in nature i.e. body is composed of three germinal layers, viz, ectoderm, mesoderm and endoderm
EXTERNAL FEATURES
Their bodies are compressed dorsoventrally and shows bilateral symmetry.
Body shape generally worm like but vary from moderately elongated flattened to long flat ribbons and leaf like.
The flat worms are small to moderate in size varying from microscopic to as long as up to 10-15 m.
Majority of animals are white or colourless, some derive colour from ingested food.
Anterior end of body is differentiated into head.
Ventral surface bearing mouth and genital pores.
Presence of great variety of adhesive parts e.g. suckers.
Body is covered by cuticle or by ciliated epidermis.
Hard part consist of cuticle, spines, thorns or hooks etc.
INTERNAL FEATURES
Endo and Exo skeleton are completely absent, hence the body is generally soft.
Acoelomate i.e. true coelom is absent.
Body space between various organs is filled with MESENCHYME.
Digestive system is poorly developed or absent.
Respiratory and Circulatory systems are absent.
Excretory system consists of Protonephridia or flame cells.
Nervous system is primitive. The main nervous system consists of a pair of cerebral ganglia or brain and 1-3 pairs of longitudinal nerve cords, connected to each other by transverse commissures.
REPRODUCTION
Platyhelmenthes are hermaphrodite i.e. male and female sex organs are present in same individual.
In majority of forms eggs are devoid of Yolk but provided with special yolk cells.
Cross fertilization as well as self fertilization is present.
Life cycle may be simple or complicated involved one or more hosts.
EXAMPLES
Planaria, Liver flukes, Schistosoma and Taenia Solium etc.
Posted by Kawish Hassan at 2:09 AM
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Phylum Chordata

GENERAL CHARACTERS
The chordate animals at some time in their life history exhibit the following diagnostic characters:
1. NOTOCHORD
It is an elastic, solid, skeletal rod lying below the nerve cord and above the alimentary canal.
It serves as a primitive internal skeleton and acts as a rigid axis.
It may persist throughout life or it may be replaced partially or completely by a backbone or vertebral column.
2. DORSAL HOLLOW NERVOUS SYSTEM
There is a dorsal, hollow, fluid filled nerve cord.
It is formed by enfolding of a mid-dorsal strip of ectoderm and it generally sinks below the surface.
It lies above the notochord and outside the coelom.
It persists throughout life in most chordates, but in a few it degenerates before maturity.
3. GILL CLEFTS
These are paired openings leading from the Pharynx to the exterior.
Such gill clefts appear during the development of every chordate, but in many aquatic forms they are lined with vascular lemallae, which forms gills for respiration.
In terrestrial chordates, which never breath by gills, gill clefts are present during early development but later on, they disappear.
4. PHA-RYNGEAL POUCHES
All the chordates have paired pharyngeal pouches at some stage of their life cycle.
These extend from laterally from the anterior part of the digestive tract towards the body wall.
OTHER FEATURES
Chordates are triploblastic.
They are bilaterally symmetrical.
True coelom is found.
They are found in almost all the habitats of the World.
CLASSIFICATION OF PHYLUM CHORDATA
The Phylum Chordata is divided into two groups which are:
1. Acraniata (Protochordata)
2. Craniata (Vertebrata)
1. GROUP ACRANIATA (PROTOCHORDATA)
They are first or simple Chordates.
Brain box (Cranium) is absent and hence brain is not prominent.
Notochord does not transform into vertebral column.
This group is further divided into two sub-phyla, which are as follows:
a) Sub-Phylum Urochordata (Notochord in tail)
b) Sub-Phylum Cephalochordata (Notochord head to tail)
A) SUB-PHYLUM UROCHORDATA (NOTOCHORD IN TAIL)
They are also known as “Tunicates” because their body is enclosed in a sac called “Tunic.”
All members are marine and sessile.
Body possesses two openings, an incurrent or buccal siphon and an excurrent or Atrial siphon, through these openings exchange of gases and food or waste material take place.
As a result of “Retrogressive metamorphosis” the larva loses its tail and most of chordate characters and converts into an adult.
E.g: Ascidia, Herdmania etc.
B) SUB-PHYLUM CEPHALOCHORDATA (NOTOCHORD FROM HEAD TO TAIL)
This is a small group of marine animals, body with pointed ends.
Usually live buried in sand, in shallow water with anterior end protruded out.
They show all typical chordate characters (hollow dorsal nerve chord, pharyngeal gill slits and notochord).
Only two genera are present around the world.
E.g: Branchiostoma (Amphioxus) etc
2. GROUP CRANIATA (VERTEBRATA)
In these chordates brain is protected inside a skeletal brain box called “CRANIUM.”
Also known as “Vertebrates” because notochord is replaced by a vertebral column.
This group is sub-divided into two sub-phyla, which are as follows:
a) Sub-Phylum Agnatha (Mouth without Jaws)
b) Sub-Phylum Gnathostomata (Mouth with Jaws)
A) SUB-PHYLUM AGNATHA (MOUTH WITHOUT JAWS)
This is a small group of marine vertebrates also known as “Cyclostomes.”
Superficially they resemble the fish but lack the jaw so they are often known as “Jawless Fishes.”
They have rounded suctorial mouth with many rings of teeth.
Paired fins and scales on body.
Usually parasitic in nature.
E.g: Hag Fish, Lamprey etc.
B) SUB-PHYLUM GNATHOSTOMATA (MOUTH WITH JAWS)
It is a large group of vertebrates with both upper and lower jaw.
Teeth may be present or absent.
Gnathostomata are divided into two super classes, which are as follows:
i) Pisces (Fishes) ii) Tetrapoda
I) SUPER CLASS PISCES (FISHES)
This is the largest group of chordates, which includes half of the chordate (25,000 species).
Study of fishes is called “Ichthyology.”
Body is streamlined with paired fins and covered over by dermal scales.
Super class Pisces is divided into two classes, which are: i-a) Chondrichthyes (Cartilage Fishes) i-b) Osteiochthyes (Bony Fishes)
I-A) CLASS CHONDRICHTHYES (CARTILAGE FISHES)
Alternate name is “Class Elasmobranchi.”
Usually includes marine fishes with endoskeleton of cartilage (soft bone).
Skin contains sharp tiny enamel coated denticles called “Placoid Scales,” which form exoskeleton.
Mouth is ventral in position and tail fin is “Heterocercal.”
Five exposed gill slits, which are not covered over by a gill cover.
Common examples are Skates, Sharks, Rays and Scoliodon (Dog Fish)- a small Shark etc.
I-B) CLASS OSTEIOCHTHYES (BONY FISHES)
Alternate name is “Teleostom,” actually the largest class of chordates.
Includes marine and fresh water fishes.
Mouth is present at anterior tip.
Endoskeleton in these fishes is made up of hard bone while exoskeleton is made up of thin bony plates, which are known as “Cycloid” or “Ctenoid scales.”
Gills are covered over on each side by a gill cover called “Operculum.”
An air bladder is present which acts as a hydrostatic organ.
Tail fin is usually “Homocercal or Diphycercal.”
Common e.g are Eel, Sea-Horse, Flying Fish, Globe Fish etc
LUNG FISHES
Zoogeographically important fishes, belonging to group “Dipnoi, included in Class Osteiochthyes.
Only three living genera.
They respire by gills and by lungs during drought period (Lungs-Modified air bladder).
Limited distribution in South America, Africa and Australia.
E.g: Protopterus (African Lung Fish)
II) SUPER CLASS TETRAPODA
It includes following classes:
a) Class Amphibia
b) Class Reptilia
c) Class Aves
d) Class Mammalia
A) CLASS AMPHIBIA
This class includes the animals that came out of the water and established a successful life on land.
They took advantages of the improved possibilities by remaining close to water, by keeping a soft and moist skin, by developing lungs and by evolving a bony skeleton with a strong vertebral column and four legs.
They cope with seasonal changes by burrowing during extreme cold and save water by sealing themselves in a mucous envelop on dry land.
The bony endoskeleton is the main body support.
The notochord is absorbed during development
Breathing is mostly by means of skin and also lung, and also by lining of buccal cavity.
In larva the breathing is mostly by means of external or internal gills.
The circulatory system shows a three chambered heart, with two atria and one ventricle.
The amphibians are “Cold Blooded” (Poikilothermic) that is having internal temperature that very with the environment.
Eggs and sperms are laid in water and fertilization is external.
E.g: Frog and Toads, Salamanders, Newts, Mud puppies etc.
B) CLASS REPTILIA
GENERAL CHARCTERS
The earliest reptiles evolved from the amphibians.
HABIT AND HABITAT
Reptiles are generally well adapted to life on land, in semi-dry, completely dry and even desert habitat.
NATURE
All reptiles lay their eggs on land.
They are cold-blooded animals and are less active during low temperature.
STRUCTURAL FEATURES
They possess dry skin covered with epidermal scales.
In some lizards and crocodiles, small bony plates develop below the epidermal scales.
The skeleton is built on the same plane as that of amphibians, but is much stronger to support their body weight.
Respiration takes place exclusively through lungs.
Heart is three chambered, two auricles and one incompletely divided ventricle. (In Crocodiles, the ventricle is completely divided into two chambers.)
The excretion takes place through kidneys. The reptiles secrete much of their waste products in form of non-toxic “Uric-Acid.”
REPRODUCTION
In most reptiles fertilization is internal.
Eggs are provided with a shell and are laid on land.
The early development of embryo takes place on the large quantities of yolk and albumin present in the egg.
Due to the presence of a protective membrane called “AMNION” in the egg, reptiles are included in the “Amniota Group” of Vertebrates.
EXAMPLE
Alligators, Crocodile, Snake, Turtle and Gecko etc.
C) CLASS AVES (BIRDS)
EVOLUTION
Aves have evolved from reptiles.
As they acquired the capability of true flight they were able to exploit the aerial environment and became the largest class of terrestrial vertebrates.
CHARACTERS OF CLASS AVES
HABIT AND HABITAT
The birds live from pole to pole in all type of ecological zones. They all breed on land.
FLIGHT AND ADAPTATION
Feathers differentiate birds from all other vertebrates.
Feathers originated as extraordinary development of Reptilian scales.
Instead of growing all over the body and spreading evenly, the feathers grow in definite tracts.
The feathers play an important role in the thermoregulation of birds. They trap air, which is a bad conductor of heat and so prevent loss of body heat.
To fly efficiently the birds have reduced their body weight in a variety of ways.
Many bones become hollow, thin and light.
Synsacrum and pygostyle are formed by the fusion of vertebrae and give strength to skeleton.
Birds possess strong muscles to control the use of wing in flight.
ADAPTATION FOR COMMUNICATION
They possess large eyes with well-developed sight.
The birds communicate with members of their species with sound signals for which the sense of hearing is well developed.
STRUCTURAL FEATURES
The great mobility of neck is helpful in feeding, nest building, preening and defence.
There are developed a number of types of bills according to their feeding habits.
The digestive system of birds is compact and can accommodate large quantity of food.
The food is stored for a short period in the crop.
“Gizzard” possess thick muscular wall with horny lining, small stones swallowed by birds are passed on the gizzard for grinding the food.
The “Syrinx” or sound-producing organ is found in no other vertebrate except the birds. It is located at the junction between the trachea and the paired bronchi.
The lungs of birds are small, solid, spongy and slightly distensible. They are in contact with a number of air sacs.
MIGRATION IN BIRDS
A large number of species of birds exhibit a deep-rooted phenomenon of migration, during which they travel long distances from their summer breeding homes towards areas of warm climate.
SUB-CLASSES OF AVES
There are two main sub-classes of aves, which are:
i) Sub-Class Ratitae (Flightless Birds) ii) Sub-Class Carinatae (Free-Flying Birds)
I) SUB CLASS RATITAE (FLIGHTLESS BIRDS)
This sub-class includes modern big sized flight less birds.
They comparatively have heavy weight and their wings are either vestigial or rudimentary.
They have a flat sternum without keel.
Their flight muscles are poorly developed.
The distribution of these birds is restricted to few areas of the World.
E.g: Ostrich, Rhea, Emu, Cassowary, Kiwi and Penguin.
II) SUB-CLASS CARINATAE (FREE FLYING BIRDS)
In this sub-class modern flying birds are included.
They are usually small, light weight birds with highly developed wings and feathers with interlocking system.
They possess sternum with a crest like keel to accommodate the hightly developed pectoral flight muscles.
The flying birds are distributed all around the World.
E.g: Sparrow, Pigeons, Myna, Bulbul, Hoopoes, Crow, Doves, Parrots, Fowls, Cuckoo and Ducks etc.
D) CLASS MAMMALIA
GENERAL CHARACTERS
Early mammals are originated from reptiles. The distinctive characteristic of mammals are at the highest grade of development in animal kingdom.
HABIT AND HABITAT
Mostly terrestrial, a few aquatic.
NATURE
They are warm-blooded animals.
They can maintain a fairly high body temperature and so can successfully survive in colder areas of the world.
TEMPERATURE REGULATION
Heat is generated by high metabolic rate of their body and is lost by increasing blood circulation in the skin and evaporation of sweat.
The mammalian body temperature is maintained at 35˚C-40˚C.
APPARENT FEATURE
All mammals possess hair on skin.
Sweat glands and sebaccous glands are present on skin.
Mammary glands secrete milk in females.
External ears (Pinna) are present.
Teeth are heterodont i.e. not uniform. The different types of teeth are: Incisors, Canine, Premolars, Molars.
SKELETAL SYSTEM
Skull with two occipital condyles is present.
Lower jaw is composed of single bone on each side.
Vertebrae are “Gastrocentrous,” composed of three pieces i.e. the centrum and two epiphyses.
Digits of fore and hind limbs are usually five.
Cervical (Neck) vertebrae are seven.
INTERNAL FEATURES
A thick muscular septum “Diaphram” is present between abdomen and thoracic cavity.
Heart is four-chambered.
R.B.Cs are non-nucleated.
Brain with four optic lobes.
Kidney is metanephrous.
The stomach is simple sac but rarely complicated.
REPRODUCTION
Mammals give birth to young ones (Viviparous), which are nourished by parents. Except Prototherians that lay eggs.
Fertilization is internal.
Development of eggs occurs in the uterus of female, where the developing embryo develops relationship with mother (Placenta).
After the birth of the child, the mother nourished her young ones.
CLASSIFICATION OF CLASS MAMMALIA
Mammals are divided into three sub-class:
1. SUB-CLASS PROTOTHERIA
Includes the egg laying mammals. For example Duck billed, Echidna (Spiny anteater).
2. SUB-CLASS METATHERIA
) NUTRITION
OMNIVOROUS, i.e. It can eat any kind of organic matter. They search their food by antennae.
TYPE OF DIGESTIVE SYSTEM
TABULAR DIGESTIVE SYSTEM, i.e. straight slightly coiled dig tube, open at both ends, complete dig. system.
ORGANS OF DIGESTIVE SYSTEM
+ ALIMENTARY CANAL
It is divisible into 3 parts
1. FORE GUT / STOMODAEUM
MOUTH
BUCCAL CAVITY
OESOPHAGUS
CROP
GIZZARD
2. MIDGUT / MESENTERON / VENTRICULUS
HEPATIC CAECA
3. HIND GUT / PROCTODAEUM
ILEUM
COLON
RECTUM
ANUS
+ ASSOCIATED GLAND
SALIVARY GLANDS
1.FORE GUT
MOUTH
It lies at base of pre-oval cavity which is bounded by mouth part.
LABRUM / UPPER LIP
Appendage of 3rd head segment.
MANDIBLES
Appendage of 4th head segment. They help in mastication
MAXILLAE
Appendages of 5th head segment. They pick up and bring food.
LABIUM / LOWER LIP
Appendages of 6th head segment.
BUCCAL CAVITY
The mouth opens into buccal cavity which is short and receives the common duct of salivary glands.
Saliva cantain ‘AMYLASE’ which act upon carbohydrates.
OESOPHAGUS
Buccal cavity opens into pharynx which in turn opens into oesophagus which is a long and thin tube lying in thorax.
CROP
It is a large thin walled and pear shaped structure meant for storing food.
GIZZARD
Crop opens into thick walled, rounded gizzard with muscular chitins lining which is internally produced six teeth for grinding and straining the food.
2. MID-GUT
It is narrow, short and tubular portion originate from gizzard. At beginning it receives eight hepatic caeca hanging in haemocoel (body cavity filled with white colour blood), ending blindly but opening in gut.
ENZYMES FROM HEPATIC CAECA
They are lined by glandular cells, which secrete enzymes.
Enzymes from hepatic caeca and mid-gut flow back into crop where digestion takes place.
ENZYMES
1. PEDTIDASES AND TRYPSIN LIKE ENZYME -> digest proteins.
2. AMYLASES -> complete digestion of starches
3. LIPASE -> digestion of fats.
Digested food form a bolus and enclosed in a thin chitinous tube secreted by stomodael valve of gizzard. This covering is called PERITROPHIC MEMBRANE.
It is permeable to enzymes and digested food. This membrane protects the lining of mid gut from damage by hard indigestible components of food.
Digested food is absorbed in mid gut.
3. HIND-GUT
It has a cuticular ectodermal lining.
ILEUM
Short, narrow and muscular ileum. The beginning of ileum is marked by 60-70 fine and long, greenish yellow MALPHIGIAN TUBULES. (excretory in function)
COLON
Colon is long, wider and coiled portion of hind gut
RECTUM
Rectum is broad last part of hind gut. It absorbs H2O and conserves the much needed H2O from undigested food before expelling out the faeces.
ANUS
Anus is the last opening of digestive system by which hind gut opens to outside.
SALIVARY GLANDS
Salivary glands are 2 in number. each present on the sides of oesophagus. Saliva contain amylase for digestion of carbohydrates.
Posted by Kawish Hassan at 2:18 AM
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Gaseous Exchange

RESPIRATORY ORGANS OF COCKROACH TRACHEAL SYSTEM
Cockroach has evolved a special type of invaginated respiratory system called Tracheal system, especially adopted for terrestrial mode of life and high metabolic rate of insects.
STRUCTURAL CONSTITUENTS OF TRACHEAL SYSTEM
1. TRACHEA
2. SPIRACLES
3. TRACHEOLES
1.TRACHEA
Tracheal system consists of number of internal tube called Trachea which are the connection between the spiracles and tracheal fluid.
2. SPIRACLES
Laterally, trachea open outside the body through minute, slit like pores called as spiracles.
There are 2 pairs of spiracles on lateral side of cockroach.
2 lie in thoracic segments and 8 in first abdominal segments.
3. TRACHEOLES
On the other side, trachea ramify throughout the body into fine branches or tracheols.
Tracheoles, finally end as blind, fluid filled fine branches which are attached with cells of tissue.
Both the trachea and tracheoles are lined internally by thin layer of cuticle.
MECHANISM OF RESPIRATION “INFLOW OF OXYGEN”
The cockroach takes in air directly from the atmosphere into the trachea through spiracles. This air diffuses directly into fluid filled tracheoles through which diffuses into the cells of tissues. Hence the blood vascular system of cockroach is devoid of haemoglobin.
OUTFLOW OF CARBONDIOXIDE
Removal of CO2 from cells of body is largely depended upon plasma of blood, which takes up CO2 for its ultimate removal through body surface via the cuticle.
RESPIRATORY SYSTEM OF FISH
MAIN RESPIRATORY ORGAN
In fish, main respiratory organs are “Gills”. They are out growth of pharynx and lie internally with in the body so that they are protected from mechanical injuries.
INTERNAL STRUCTURE OF GILLS
Each gill is highly vascularized structure. It is composed of
1. Filaments
2. Gill bar or Gill arch
3. Lamella
1. FILAMENTS
Each gill is composed of two rows of hundreds of filaments, which are arranged in V-shape.
2. GILL BAR OR GILL ARCH
Filaments are supported by a cartilage or a long curved bone the gill bar or gill arch.
3. LAMELLA
Lamella is a plate like structure which is formed by infolding of filaments. Lamella greatly increase the surface area of the gill. Each lamella is provided by a dense network of capillaries.
OPERCULUM (IN BONY FISHES)
Gills are covered on each side by gill cover called “operculum”
MECHANISM OF VENTILATION
In bony fishes, ventilation is brought about by combined effect of mouth and operculum.
Water is drawn into the mouth. It passes over the gills through pharynx and ultimately exists at the back of operculum through open operculur valve.
Water is moved over the gills in a continuous unidirectional flow by maintaining a lower pressure in operculur cavity than in buccopharynx cavity.
COUNTER CURRENT FLOW OF WATER AND BLOOD
Gaseous exchange is facilitated in gills due to counter current flow of H2O and blood.
In the capillaries of each lamella, blood flows in direction opposite to the movement of water across the gill. Thus the most highly oxygenated blood is brought to water that is just entering the gills and has even high O2 content than the blood. As the H2O flows over the gills, gradually loosing its oxygen to the blood, it encounter the blood that is also increasingly low in oxygen. In this way a gradient is establishment which encourages the oxygen to move from water to blood
IMPORTANCE
Counter current flow is very effective as it enables the fish to extract upto 80–90% of the oxygen from water that flows over the gills.
RESPIRATORY SYSTEM OF MAN
MAIN FUNCTION OF RESPIRATION
The main function of respiratory system is inflow of O2 from the atmosphere to the body and removal of CO2 from body to the atmosphere.
COMPONENTS OF RESPIRATORY SYSTEM
(1) PAIRED LUNGS
The respiratory (gas exchange) organs.
(2) AIR PASSAGE WAYS
Which conduct the air
(3) THORACIC CAVITY
Which lodges the lungs
(4) INTERCOSTAL MUSCLES AND DIAPHRAGM
Which decreases and increase the diameters of thoracic cavity
(5) RESPIRATORY CONTROL CENTRES
Areas in brain which control the respiration.
DETAILS OF COMPONENTS
+ THORACIC CAVITY
Paired lungs with in the pleural sacs are situated in the thoracic cavity. Separating the thoracic cavity from the abdominal cavity is a dome-shaped musculo-tendinuous partition called as Diaphragm.
BOUNDARIES OF CAVITY
Thoracic cavity is supported by bony cage (thoracic cage) which is made up of
Sternum -> in front
Vertebral column -> at the back
12 pairs of ribs -> on each side
Ribs are supported by Intercostal muscles
FUNCTION
Increase in thoracic cavity diameter is responsible for inspiration. While decrease in diameter is responsible for expiration.
AIR PASSAGE WAYS
Air is drawn into the lungs by inter-connected system of branching ducts called as “Respiratory tract” or “Respiratory passage ways”
Air passage ways consists of
AIR CONDUCTING ZONE(which only conducts the air)
1. Nostrils
2. Nasal Cavity
3. Pharynx (nasopharynx and oropharynx)
4. Larynx
5. Trachea
6. Bronchi
7. Bronchioles (also called terminal Branchioles)
RESPIRATORY ZONE(Where gaseous exchange takes place)
8. Respiratory Bronchioles
9. Alveolar duct
10. Alveolar sacs or alveoli
GENERAL FUNCTIONS OF CONDUCTING AIR PASSAGES
1. Conduction of air from atmosphere to the lungs
2. Humidification of inhaled dry air.
3. Warming / cooling of air to body temp.
4. The injurious particles are entrapped by mucous and removed by ciliary movements.
5. Lymphoid tissues of pharynx provide immunological functions
6. Cartilages prevent the passages from collapse but are not present in Bronchioles which remains expanded by same pressure that expand the alveoli.
CONDUCTING ZONE
1. NASAL CAVITY
Atmospheric air enters the respiratory tract through a pair of openings called external nares (Nostrils), which lead separately into nasal cavity. Nasal cavity opens into naso pharynx through posterior nares (choanae).
Nasal cavity is lined internally by Pseudostratified columnar ciliated epithelium containing mucous secreting cells.
Hairs, sweat and sebaceous glands are also present.
SPECIALIZED FUNCTIONS
Warming of air
Humidification or moistening of air
Filteration of air with the help of hairs
All these together called as Air conditioning function of upper respiratory passages
Olfaction ( sense of smell)
2. PHARYNX
Air enters from Nasal cavity into pharynx through internal nostrils. The openings of nostrils are guarded by soft palate. It is internally lined by Pseudostratified ciliated epithelium, mucous glands are also present.
FUNCTION
Pharynx is responsible for conduction of air as well as food
3. LARYNX (VOICE BOX)
Pharynx leads air into larynx through an opening called glottis. Glottis is guarded by flap of tissue called epiglottis. During swallowing, soft palate and epiglottis close the nostrils opening and glottis respectively so that food is prevented to go either into nasal cavity or glottis. Larynx, a small chamber consists of pair of vocal cords
FUNCTION
During speech, vocal cords move medially and their vibration produce sound
4. TRACHEA (WIND PIPE)
Larynx leads the air into a flexible air duct or trachea. It bears C-shaped tracheal cartilages which keep its lumen patent during inspiration. Its internal lining is pseudostratified columnar ciliated epithelium containing mucous secreting goblet cells.
FUNCTION
Conduction of air
Due to mucous and upward beating of cilia, any residues of dust and germs are pushed outside the trachea towards the pharynx.
5. BRONCHI
“At its lower end, trachea bifurcates into two smaller branches called Principle Bronchi↑ which leads the air into lung of its side. They are also supported by C-shaped cartilage rings upto the point where they enter the lungs”.
In all areas of trachea and bronchi, not occupied by cartilage plates, the walls are composed mainly of smooth muscles.
6. BRONCHIOLES
On entering the lungs, each bronchus divide repeatidly. As the bronchi become smaller, U-shaped bars of cartilage are replaced by irregular plates of cartilages. The smallest bronchi divide and give rise to Bronchioles (less than 1.5 mm in diameter).
7. TERMINAL BRONCHIOLES
Bronchioles divide and give rise to terminal bronchioles (less than 1 mm in diameter). Walls possess no cartilages and are almost entirely the smooth muscles. These are the smalled airways without alveoli.
RESPIRATORY ZONE
In this zone of respiratory tract, gaseous exchange between capillary blood and air takes place.
1. RESPIRATORY BRONCHIOLES
Terminal bronchioles show delicate outpouchings from their walls, which explains the name Respiratory Bronchioles (less than 0.5 mm in diameter). They bear the pulmonary alveoli.
2. ALVEOLAR DUCTS AND SACS
Each respiratory bronchioles terminates at a tiny hollow sac like alveolar duct that lead into tabular passages with numerous thin walled out pouchings called Alveolar sacs.
3. PULMONARY ALVEOLI
The alveolar sacs consists of several alveoli openings into a single chamber. Alveoli are the site of exchange of respiratory gases so they are considered as Respiratory surfaces of lungs. Each alveolus is surrounded by a network of blood capillaries.
INTERNAL STRUCTURE OF ALVEOLI
The alveolar lining cells consists of
1. Type I cells
2. Type II cells
They are also called pneumocytes.
“Bifurcation of trachea is called Carina”.
TYPE I PNEUMOCYTES
Squamous shaped cells which form the epithelial lining of alveoli
TYPE II PNEUMOCYTES
Irregular and cuboidal shaped cells which secretes a substance called Surfactant
SURFACTANT
The internal area of an alveoli is provided with a thin layer of fluid called as Surfactant secreted by type II cells.
FUNCTION OF SURFACTANT
1. It reduces the internal surface tension of alveoli which prevent it collapsing during expiration.
2. It increases the compliance.
3. It stabilize the alveoli.
4. It also helps to keep the alveoli dry.
LUNGS
Lungs are paired, soft, spongy, elastic and highly vascularized structures, which occupy most of thoracic cavity. In child they are pink, but with age they become dark and mottled due to inhalation of dust.
RIGHT LUNG
Partitioned into 3 lobes by two fissures.
LEFT LUNG
Divided into 2 lobes by one fissures.
PLEURAL MEMBRANES
Each lung is enclosed by two thin membranes called as Visceral and parietal pleural membranes.
PLEURAL CAVITY
In between the membranes there is a narrow cavity, the pleural cavity filled with pleural fluid which acts as lubricant.
FUNCTION OF CAVITY
1. Cardinal function is to exchange gases.
2. Phagocytosis of air borne particles
3. Temperature regulation
4. Removal of water
5. Maintainence of acid-base balance (by elemination of CO2)
6. Acts as Reservoir of blood.
BREATHING
DEFINITION
“Breathing is the process of taking in (inspiration or inhalation) and giving out of air (expiration or exhalation) from the atmosphere up to the respiratory surface and vice versa”
TYPES OF BREATHING
There are two types of Breathing
Negative pressure Breathing
Positive pressure Breathing
NEGATIVE PRESSURE BREATHING
Normal breathing in man is termed as negative pressure breathing in which air is drawn into the lungs due to negative pressure (decrease in pressure in thoracic cavity in relation to atmospheric pressure).
POSITIVE PRESSURE BREATHING
“In this kind of breathing, lungs are actively inflated during inspiration under positive pressure from cycling valve”.
EXAMPLES
Frog uses positive pressure breathing.
PHASES OF BREATHING
1. INSPIRATION OR INHALATION
2. EXPIRATION OR EXHALATION
(1) INSPIRATION
DEFINITION
“Inspiration is an energy consuming process in which air is drawn into the lungs due to negative pressure in thoracic cavity”
MECHANISM
During inspiration volume of thoracic cavity increases which creates a pressure (intra thoracic) that sucks the air into the lungs.
INCREASE IN VOLUME OF THORACIC CAVITY
Volume of thoracic cavity increases due to
1. Inc. in Anterio-posterior diameter
2. Inc. in Vertical diamter.
INCREASE IN ANTERIO-POSTERIOR DIAMETER During contraction of external intercostals muscle, the ribs as well as the sternum move upward and outward, which causes the increase in anterior-posterior diameter of thoracic cavity.
INCREASE IN VERTICAL DIAMETER
Vertical diameter of thoracic cavity inc. due to Contraction (descent) of Diaphragm which makes it flat.
As a consequence thoracic cavity enlarges and the pressure is developed inside the thoracic cavity and ultimately in the lungs. So the air through the respiratory tract rushes into the lungs upto the alveoli where gaseous exchange occurs.
(2)EXPIRATION
DEFINITION
“It is reserve of inspiration. The passive process in which air is given out of lung due to increased pressure in thoracic cavity is called “Expiration”
MECHANISM
During expiration, elastic recoil of pulmonary alveoli and of the thoracic wall expels the air from the lungs.
DECREASE IN VOLUME OF THORACIC CAVITY
Volume of thoracic cavity ↓ due to
1. DECREASE IN ANTERIO-POSTERIOR DIAMETER
2. DECREASE IN VERTICAL DIAMETER
(1) DECREASE IN ANTERIO-POSTERIOR DIAMETER
It is caused by relaxation of external intercostals muscles and contraction of internal intercostals muscles which moves the ribs and sternum inward and downward.
(2) DECREASE IN VERTICAL DIAMETER
It is caused by relaxation of diapharagm which makes it dome shaped thus reducing the volume of thoracic cavity.
As a consequence, the lungs are compressed so the air along with water vapours is exhaled outside through respiratory passage.
CONTROL OF RATE OF BREATHING
Rate of breathing can be controlled by two modes.
VOLUNTARY CONTROL
INVOLUTARY CONTROL
VOLUNTARY CONTROL
Breathing is also under voluntary control by CEREBRAL CORTEX
EXAMPLES
We can hold our breath for short time or can breath faster and deeper at our will.
INVOLUNTARY CONTROL
Mostly, rate of breathing is controlled automatically. This is termed as Involuntary control which is maintained by coordination of respiratory and cardio-vascular system.
TWO MODES OF INVOLUNTARY CONTROL
A. NERVOUS CONTROL (through respiratory centers in brain)
B CHEMICAL CONTROL (through chemoreceptors)
(A) NERVOUS CONTROL
Control of rate of breathing by nervous control is through the Respiratory centers in Medulla oblongata which are sensory to the changes in Conc. of CO2 and H+ present in the cerebro-spiral fluid (CSF).
RESPIRATORY CENTRES IN MEDULLA
Two center are present

(1) DORSAL GROUP OF NEURONS
Medulla contains a dorsal group (Inspiratory group) of neurons responsible for inspiration
FUNCTION
In response to increase conc. of CO2 and H+ (decreased pH), it sends impulses to the intercostals muscles to increase the breathing rate
(2) VENTRAL GROUP OF NEURONS
Another area in the medulla is ventral (expiratory) group of neurons.
FUNCTION
It inhibits the dorsal group and mainly responsible for expiration
(B) CHEMICAL CONTROL
Chemical control of rate of breathing is through chemoreceptors.
LOCATION OF CHEMORECEPTORS
AORTIC BODIES
CAROTID BODIES
AORTIC BODIES
The peripheral chemoreceptors which are located above and below the arch of aorta are called Aortic bodies. It sends impulses to medulla through Vagus nerve.
CAROTID BODIES
Chemoreceptors which are located at the bifurcation of carotid arteries are called Carotid bodies. It sends impulses to medulla through Glossopharyngeal nerve.
FUNCTION
Inc. in concentration of CO2 and H+ in blood are basic stimuli to increase the rate of breathing which are monitered by these chemoreceptors and then send the impulses to medulla oblongata which produce action potential in inspiratory muscles.
DISORDERS OF RESPIRATORY TRACT
(1) LUNG CANCER (BRONCHIAL CARCINOMA)
CAUSES
Smoking is a major risk factor either acitively or passively.
Asbestos, nickel, radioactive gases are associated with increased risk of bronchial cascinoma
PHYSIOLOGICAL EFFECTS
+ LOSS OF CILIA
The toxic contents of smoke such as nicotine and SO2 cause the gradual loss of cilia of epithelical cells so that dust and germ are settled inside the lungs.
+ ABNORMAL GROWTH OF MUCOUS GLANDS
Tumor arises by uncontrolled and abnormal growth of bronchial epithelium mucous glands. The growth enlarges and some times obstruct a large bronchus.
The tumours cells can spread to other structures causing cancer.
SYMPTOMS
Cough- due to irritation
Breath lessness – due to obstruction.
(2)TUBERCLOSIS (KOCH’S DISEASE)(INFECTIOUS DISEASE OF LUNG)
CAUSE
Caused by a Bacterium called as “MYCOBECTERIUM TUBERCLOSIS”
PHYSIOLOGICAL EFFECTS
Tuber Bacili causes
Invasion of infected region by macrophages
Fibrosis of lungs thus reducing the total amount of functional lung tissues
These effects cause
Increased work during breathing
Reduced vital and breathing capacity
Difficulty in diffusion of air from alveolar air into blood.
SYMPTOMS
Coughing (some time blood in sputum)
Chest pair
Shortness of breath
Fever
Sweating at night
Weight loss
Poor apetite
PREVENTION
A live vaccine (BCG) provides protection against tuberclosis.
3.COPD-(CHRONIC OBSTRUCTIVE PULMONARY DISEASE)
They include
A. Emphysema
B. Asthma
(3-A)EMPHYSEMA
CAUSES
It is a chronic infection caused by inhaling Smoke and other toxic substances such as Nitrogen dioxide and Sulphur dioxide
PHYSIOLOGICAL EFFECTS
Long infection – Irritants deranges the normal protective mechanisms such as loss of cilia, excess mucus secretion causing obstruction of air ways
Elasticity of lung is lost
Residual volume increases while vital capacity decreases.
Difficulty in expiration due to obstruction
Entrapment of air in alveoli
All these together cause the marked destruction of as much as 50-80% of alveolar walls.
Loss of alveolar walls reduces the ability of lung to oxygenate the blood and remove the CO2
Oxygen supply to body tissues especially brain decreases.
SYMPTOMS
Victim’s breathing becomes labored day by day.
Patient becomes depressed, irritable and sluggish.
Concentration of CO2 increases which may cause death.
(3-B) ASTHAMA
“Respiratory tract disorder in which there are recurrent attacks of breathlessness, characteristically accompanied by wheezing when breathing out.”
CAUSES
It is usually caused by Allergic hypersensitivity to the plant pollens, dust, animal fur or smoke or in older person may be due to common cough.
Heridity is major factor in development of Asthma.
PHYSIOLOGICAL EFFECTS
Localized edema in walls of small bronchioles.
Secretion of thick mucus.
Spastic Contraction of bronchial smooth muscles (so the resistance in air flow increases).
Residual volume of lung increases due to difficulty in expiration.
Thoracic cavity becomes permanently enlarged.
SYMPTOMS
The asthmatic patient usually can inspire quite adequately but has great difficulty in expiring.
LUNG CAPACITIES
1. TOTAL AVERAGE LUNG CAPACITY
DEFINITION

“It is the maximum volume in which the lung can be expanded with greatest possible inspiratory efforts.”

Or
“Total lung capacity is the combination of residual volume and vital capacity.
VALUE
Total lung capacity = 5000 cm3 or 5 lit of air.
2. TIDAL VOLUME
“The amount of air which a person takes in and gives out during normal breathing is called Tidal Volume.”
VALUE
450cm3 to 500 cm3 (1/2 litre)
3. INSPIRATORY RESERVE VOLUME
DEFINITION
‘“Amount of air inspired with a maximum inspiratory effort in excess of tidal volume.”
VALUE
200 cm3 or 2 lit. (Average value)
4. EXPIRATORY RESERVE VOLUME
DEFINITION
“Amount of air expelled by an active expiratory effort after passive expirations.”
VALUE
1000 cm3 or 1 litre.
5. VITAL CAPACITY
DEFINITION

“After an extra deep breath, the maximum volume of air inspired and expired is called Vital capacity.”
Or
“It is the combination of inspiratory reserve volume, expiratory reserve volume and tidal volume.”
VALUE
Averages about 4 litre.
6. RESIDUAL VOLUME
DEFINITION

“Amount of air which remains in lung after maximum expiratory effort is called Residual volume.”
VALUE
Approximately 1 litre or 1000 cm3.
IMPORTANCE OF LUNG CAPACITY
Residual volume prevent the lung from collapsing completely.
Responsible for gaseous exchange in between breathing.
It is not stagnant since inspired air mixes with it each time.
Aging or Emphysema, etc can increase the residual volume at the expense of vital capacity.
HAEMOGLOBIN
INTRODUCTION
“Haemoglobin is an iron containing respiratory pigment present in the red blood cells of vertebrates and responsible for their red colour.”
STRUCTURE
Haemoglobin consists of
1. Heme
2. Protein (globin like chains)
1. HEME
One Haemoglobin molecule consists of 4 molecules of Heme. Each Heme molecule contains an iron (Fe++) binding pocket. Thus one molecule of Haemoglobin can combine with 4 iron atoms.
2. GLOBIN
Each Hb molecule contains four globin like chains (Two α chains and Two β chains).
ROLE OF HB DURING RESPIRATION
Two major functions are performed by Hb.
1. Transport of O2 from lung to tissues.
2. Transport of CO2 from tissues to lungs.
1. “TRANSPORT OF O2 FROM LUNGS TO TISSUES”
“Nearly 97% of O2 is transported from the lungs to the tissues in combination with Hb.”
ATTACHMENT OF O2 WITH HB
It is the iron of Hb molecule which reversibly binds with oxygen. One Hb molecule can bind 4 molecules of O2. Thus due to Hb, blood could carry 70 times more oxygen than plasma.
MECHANISM OF TRANSPORT
Due to high O2 concentration in alveolar air, the O2 moves from air to the venous blood where O2 concentration is low.
It combines loosely with Hb to form Oxyhemo Globin.
In this form, O2 is carried to the tissues where due to low oxygen concentration in tissues, oxy Hb dissociates releasing oxygen, which enters in tissues.
Whole process can be represented by following equation.
2. “TRANSPORT OF CO2 FROM TISSUES TO LUNGS”
“Haemoglobin is also involved in 35% of transport of CO2 from tissues to alveolar blood capillaries in alveoli.”
ATTACHMENT OF CO2 WITH HB
CO2 binds reversibly with NH2 group of Hb to form loose compound called “Carboamino Haemoglobin.”
MECHANISM OF TRANSPORT
Carbon dioxide due to its higher concentration in tissue diffuses out into the blood where it combines with Hb to form Carboamino Hb.
In the alveoli it breaks and CO2 diffuses out into the Alveoli from where it is expired.
MYOGLOBIN
INTRODUCTION
“Myoglobin is a heme protein, smaller than Hb, found in muscles and giving red colour to them.
STRUCTURE
Myoglobin consists of one heme molecule and one globin chain. It can combine with one iron (Fe++) atom and can carry one molecule of O2.
FUNCTION OF MYOGLOBIN
Myoglobin has high affinity for O2 as compared to Haemoglobin so it binds more tightly.
It stores the O2 within the muscles.
It supplies the O2 to the muscles when there is severe oxygen deficiency (During exercise)
It can be represented as follows:
Mb + O2 ↔ MbO2
TRANSPORT OF GASES
Oxygen and carbondioxide are exchanged in, Alveoli by Diffusion.
O2 TRANSPORT
Blood returning into the lungs from all parts of body is depleted from oxygen. This deoxygenated blood is dark maroon in colour to appear bluish through skin. It becomes oxygenated in the lungs.
TWO FORMS OF O2 IN BLOOD
O2 is transported in the blood in two forms:
Dissolved form (3%)
Combination with Hb (97%) ® Oxyhaemoglobin
MECHANISM OF O2 TRANSPORT
+ DIFFUSION OF O2 FROM ALVEOLUS INTO PULMONARY BLOOD
The air inhaled into the lungs has high concentration of oxygen while venous blood in pulmonary capillaries has low in concentration. Due to this difference in concentration across the respiratory surface, oxygen diffuses into the blood flowing into capillaries around the Alveoli. Now blood becomes oxygenated which is bright red in colour.
+ DIFFUSION OF O2 FROM CAPILLARIES INTO CELLS
Concentration of O2 in the arterial end of capillaries is much more greater than concentration of O2 in the cells. So O2 diffuses from the blood to the body cells. Since the blood takes in oxygen much more rapidly than water. Thus it can transport enough oxygen to the tissues to meet their demand.
CO2 TRANSPORT
Blood returning from tissues contain excess of CO2 as a respiratory by-product, which is eliminated from the body during expiration in the lungs.”
THREE FORMS OF CO2 IN BLOOD
Dissolved form (in plasma) – 5%
In form of HCO3- (in RBC’s) – 60%
In combination with Hb (Carboamino Hb) – 35%
+ DISSOLVED FORM
Only 5% of CO2 is transported in dissolved form in plasma. Here it combines with H2O of plasma to form H2CO3. But this reaction is very slow as plasma does not contain Carbonic Anhydrase to accelerate this reaction.
Reactions can be represented by following equations.
CO2 + H2O ↔ H2CO3
H2CO3 ↔HCO3- + H+
HCO3- + k+ ↔ KHCO3
+ IN FORM OF HCO3-
60% of CO2 is transported in the blood in form of HCO3- in RBC’s. Here it combines with water to form H2CO3. But this reaction occurs rapidly in RBC’s due to presence of Carbonic Anhydrase.
Reactions can be represented by following equations
CO2 + H2O ↔ H2CO3
H2CO3 ↔ HCO3- + H+
HCO3- + Na+ ↔ NaHCO3
+ IN COMBINATION WITH HB
As discussed previously in role of Hb.
MECHANISM OF CO2 TRANSPORT
+ DIFFUSION OF CO2 FROM CELLS INTO CAPILLARIES
CO2 is continuously synthesizing in the tissues as a result of metabolism. Thus due to its higher concentration. CO2 diffuses from the tissues into blood, which becomes deoxygenated.
+ DIFFUSION OF CO2 FROM PULMONARY BLOOD INTO ALVEOLUS
Blood returning from tissues contain high concentration of CO2. This blood is brought to lungs, where CO2 diffuses from the blood into alveolus where its concentration is lower.
FACTORS EFFECTING THE TRANSPORT OF GASES
Following are some factors, which influence the transport of respiratory gases across the alveolar wall.
1. Concentration Gradient
2. Presence of competitor such as CO
3. Moisture
4. Surfactant
5. pH
Posted by Kawish Hassa
Immune System

IMMUNITY
DEFINITION
“The ability of human body to resist almost all types of micro-organisms, their toxins if any, foreign cells & abnormal cells of the body is termed as “Immunity”
IMMUNOLOGY
DEFINITION
“The study of functioning & disorders of Immune system is termed as “Immunology”.
IMMUNE SYSTEM
Immunity is conferred to animals through the activities of the Immune System, which combats infectious agents.
DEFINITION
“Immune System is a collection of cells & proteins that work to protect the body from potentially harmful, infectious micro-organisms”
MAIN FUNCTIONS OF IMMUNE SYSTEM
Protection of body from all types of micro organisms & toxins that tend to damage the tissues and organs of body.
ADDITIONAL FUNCTIONS
Immune system also play important role in:
Control of cancer
Allergy
Hypersensitivity
Rejection problems when organs or tissues are transplanted.
DIVISIONS OF IMMUNE SYSTEM
Immune system can be divided into two functional divisions:
1. Innate Immunity System
2. Acquired Immunity System
INNATE IMMUNITY
DEFINITION
“The NON SPECIFIC type of immunity which result from general processes , rather than from processes directed at specific disease organism (Such as antigen –antibody reaction) is called. INNATE OR NATURAL IMMUNITY & the system which is responsible for this type of immunity is called Innate IMMUNITY System.
TYPES OF BARRIERS PROVIDED BY INNATE IMMUNITY SYSTEM
This system provides two types of barriers:
Physical Barrier
Chemical Barrier
PHYSICAL BARRIERS
SKIN
MUCOUS MEMBRANE & etc.
CHEMICAL BARRIERS
Lysozyme
Gastric juice (Acidic secretion of stomach) & etc.
FIRST LINE OF DEFENCE
Skin, Mucous membrane & their secretions act as “First line of Defence”
1. SKIN
The intact skin provides an impenetrable barrier to the vast majority of infectious agents.
2. MUCOUS MEMBRANES
Most of the micro-organisms can enter only through the mucous membranes that lines the digestive, respiratory & urogenital tracts. However these areas are protected by movements of mucous & secretions (e.g Lysozyme in tears) to destroy many microbs.
3. ACIDIC SECRETIONS
Most of he microorganisms present in food or trapped in swallowed mucus from the upper respiratory tracts are destroyed by highly acidic gastric juice of stomach.
SECOND LINE OF DEFENSE
If some how micro-organisms are able to penetrate the outer layer of the skin or mucous membrance, they encounter a second line of Defence offered by Innate Immunity system.
It is non specific & comprises of
1. PHAGOCYTES
2. ANTIMICROBIAL PROTEINS
3. INFLAMMATORY RESPONSE
1. PHAGOCYTES
Phagocytes are certain type of WBC’S which can injest internalize & destroy the particles including infectious agents.
EXAMPLES OF PHAGOCYTIC CELLS
NEUTROPHILS
MACROPHAGES
NEUTROPHILS
Neutrophils (Polymorphonuclear Neutrophiles are short lived phagocytic cells which can ingest the bacteria or any foreign matter very actively.
MACROPHAGES (BIG EATERS)
The other phagocytic cells, the MONOCYTE can develop into large LONG-LIVED MACRO PHAGES when they reside in various tissues of body. ALSO CALLED AS ANTIGEN PRESENTING CELLS.
Macrophages not only destroy individual micro organisms but also play a crucial rule in further immune response by “Presenting” parts of that microorganisms to other cells of immune system. For this reason, they are termed as “ANTIGEN PRESENTING CELLS.
NATURAL KILLER (NK ) CELLS
Natural killer cells (NK Cells ) are the large lymphocytes, which destroy the
Virally infected own cells of the body
Foreign cells
Abnormal cells (cancerous cells)
MECHANISM OF ACTION (CYTOTOXICITY)
NK cells do not phagocytize the target cells, instead, they bind to their target cells, release some PORE FORMING PROTEINS (PERFORINS), that literally punch large round holes in the membrane of attacked cells & eventually cause lysis of the target cells. This kind of destroying the target cells is called “CYTOTOXICITY”
2. ANTIMICROBIAL PROTEINS
EXAMPLES
Important antimicrobial proteins are:
Lysozyme
Compliment proteins
Interferon
LYSOZYMES
Lysozyme, is a mucolytic polysaccharide that causes the LYSIS OF BACTERIA it is present in TEARS, SALIVA, & MUCUS SECRETION.
COMPLEMENT PROTEINS
Complement is a collective terms that describes a system of about 20 PROTEINS, many of which are INACTIVE ENZYME PRECURSORS. The principal actors in this system are 11 Proteins. All these proteins are present among the Plasma Proteins.
ACTIVATION OF COMPLIMENT PROTEINS
These proteins can be activated by two ways.
CLASSICAL PATH WAY-Act in Adaptive Immunity system.
ALTERNATIVE PATH WAY- Act in Innate Immunity System.
FUNCTIONS
Main functions of compliment proteins are as follows:
1. DIRECT LYSIS OF BACTERIA
2. PROMOTE THE PHAGOCYTOSIS OF BACTERIA
3. NEUTRILIZATION OF VIRUSES
4. CHEMOATTRACTANTS FOR MACROPHAGES.
INTERFERONS (ANTIVIRAL AGENTS)
Interferon are secreted by virally infected cells or some lymphocytes to induce a state of ANTI VIRAL RESISTANCE in unaffected tissues of the body.
3. INFLAMMATION
Inflammation is the body’s reaction to an injury or by entry of micro organisms.
EFFECTS OF INFLAMMATION
A cascade of chemical reactions take place during inflammatory response.
1. When injured, BASOPHILS and MAST CELLS release a substance called HISTAMINE which causes.
Increased permeability of adjacent capillaries.
Local vasodilatation
Increased leakage of capillaries.
2. Due to CHEMOTAXIS, Phagocytes & macrophages are attracted at the injured site. Thus Phagocytes literally eat up microorganisms, dirt, cell debris & etc forming pus.
SYMPTOMS
Redness, heat, swelling, pain in injured tissue.
FEVER -(ALSO CONTRIBUTES TO DEFENSE OF BODY)
In case of warm blooded animals, a no. of micro organisms who escape away from inflammatory response to infect some large part of the body, trigger FEVER. It is usually caused by WBC’S, that release the substance called as PYROGEN.
FUNCTIONS
High fever is dangerous but moderate fever contributes to the defense of the body.
It inhibits the growth of micro-organisms.
May speed up the repair of damaged tissues.
Facilitates the phagocytosis, increase the production of interferons.
ADAPTIVE IMMUNE SYSTEM
DEFINITION
“The specific type of Immunity which does not develop until after the body is first attacked by a bacterial disease or a toxin, is called “Adaptive or Acquired Immunity”. The system which provides this type of immunity is called “ADAPTIVE or ACQUIRED IMMUNE SYSTEM”

OR
“Acquired Immunity is provided by special Immune System that form Antibodies & activated lymphocytes that attack & destroy the specific organisms or toxins. This is the THIRD LINE OF DEFENCE.
DEVELOPMENT OF IMMUNE SYSTEM (LYMPHOCYTES ARE THE BASIS OF ADAPTIVE IMMUNE SYSTEM)
Acquired Immune system is actually the product of body’s Lymphocytic system. The responses of adaptive Immune system is provided by Lymphocytes.
TYPES OF LYMPHOCYTES
During fetal development, all lymphocytes come from Bone Marrow. But depending upon their migration & maturity, they can be divided into two populations.
1. “T” – Cells or “T” LYMPHOCYTES
2. “B” – Cells or “B” LYMPHOCYTES.
1. “T” LYMPHOCYTES
DEFINITION
“The lymphocytes that are destined to eventually form ACTIVATED “T” LYMPOCYTES first migrate to & then mature in THYMUS GLAND, that is why, they are called as “T” LYMPHOCYTES”
FUNCTIONS
These are responsible for “CELL-MEDIATED IMMUNITY
2. “B” LYMPHOCYTES
DEFINITION
“The lymphocytes that are destined to form ANTIBODIES are processed first in the LIVER (before birth) & then in BONE MARROW (after the birth). This population of cells was first discovered in birds where processing occurs in BURSA OF FABRICIUS (not found in mammals), hence they are called as “B” LYMPHOCYTES.”
FUNCTIONS
These are responsible for HUMORAL IMMUNITY
ADAPTIVE IMMUNE SYSTEM IS INITIATED BY ANTIGENS
In order to develop a specific immune response, the immune system must recognize the invading organisms and / or foreign proteins from its self tissues & proteins.
ANTIGEN
Any foreign substance, that elicit the immune response is called antigen. In general Antigens are proteins or large polysaccharides.
RESPONSE OF IMMUNE SYSTEM TO ANTIGEN
The immune system responds to an antigen by ACTIVATING LYMPHOCYTES & PRODUCING ANTIBODIES (Soluble Proteins). The antibody combines with antigen & helps to eliminate it from the body.
BASIC TYPES OF ADAPTIVE IMMUNITY
The adaptive immune system mounts two types of attacks on invading micro-organisms.
1. HUMORAL IMMUNITY
2. CELL MEDIATED IMMUNITY (CMI)
1. HUMORAL IMMUNITY
DEFINITION
“The immunity which is mediated by circulating antibodies produced by B-lymphocytes is called “ HUMORAL IMMUNITY”.

MAJOR FUCTIONS OF HUMORAL IMMUNITY
Humoral Immunity provides major defence against “BACTERIAL INFECTIONS
MECHANISM OF ACTION OF B CELLS
“B” CELL RECEPTORS
Each B-cell has specific type of antibodies on its cell surface. This antibody serves as ANTIGENIC RECEPTOR.
ACTIVATION OF SPECIFIC “B” CELLS
On entry of foreign antigen, those B cells specific for that antigen enlarge immediately, becomes activated & form two types of cells:
1. PLASMA CELLS
2. MEMORY CELLS
1. PLASMA CELLS
The activated B-cells proliferate rapidly & transform into enlarged effectors cells called plasma cells.
FUNCTION
Plasma cells secrete ANTIBODIES into the circulation that help to eliminate that particular antigen.
ACTIONS OF ANTIBODIES.
After the formation of antigen-antibody complex antibody can inactivate the invading agent in one of the several ways.
By activation of complement system that cause the Lysis.
Direct Phagocytosis.
Neutralization of the toxins released by bacteria.
Agglutination of microorganism.
2. MEMORY CELLS
DEFINITION
Some of the activated B-cells don’t go on to form the plasma cells but instead, form moderate number of new B-cells, which don’t secrete antibodies such cells are called as Memory cells.

FUNCTIONS
The memory cells play important role in future immunity to this specific organism in case of re-infection.
2. CELL MEDIATED IMMUNITY (CMI)
DEFINITION
The second type of acquired immunity is achieved through the formation of large number of Activated LYMPHOCYTES. This is called cell mediated or T-cell immunity.
FUNCTIONS OF CMI
CMI is responsible for delayed allergic reactions & rejection of transplantation of foreign tissue.
It provides major defence against infections due to VIRUSES, FUNGI, TUBERCLE BACILLI & some parasites.
It also provides defence against TUMOUR CELLS.
MECHANISM OF ACTION OF “T”-CELLS.
T-CELL RECEPTORS (TCRS)
Antigens bind with specific RECEPTOR MOLECULES on the surface of T-Cells, in the same way that they bind the antibodies.
ACTIVATION OF SPECIFIC “T” CELLS.
On exposure to proper antigen, the “T” cells of specific type proliferate & release large no. of activated T-Cells.
SEVERAL TYPES OF “T” CELLS
Different types of T cells are classified into four major groups.
1. HELPER “T” CELLS
2. CYTOTOXIC “T” CELLS
3. SUPRESSER “T” CELLS
4. MEMORY “T” CELLS
1. HELPER “T” CELLS
Helper T cells are the MAJOR REGULATOR of all the immune functions.
RECEPTORS
Helper T cell receptors actually recognize a combination of antigen fragment & one of the body’s own self marker called. “MAJOR HISTO-COMPATIBILITY” (MHC) CLASS II molecules on the surface of macrophages or B cells.
FUNCTIONS
Helper T-cells secrete the LYMPHOKINES which stimulate the production of both CYTOTOXIC & SUPRESSER TOXINS.
2. CYTOTOXIC “T” CELLS (KILLER CELLS)
RECEPTORS
Receptors on the surface of cytotoxic ‘T” cells recognize a combination of antigen fragment & self surface marker molecules called MHC CLASS I , found on every nucleated cells of its own body.
FUNCTIONS
They are especially lethal to virally infected cells. They also destroy the cancer cells, heart transplant cells & other foreign cells.
3. SUPRESSOR “T” CELLS
Along with helper cells, In supressor, T-cells are classified as Regulatory T-Cells
FUNCTIONS
After the conquerence of infection, they seems to shut off the immune response in both B-cells & cytotoxic T-cells.
4. MEMORY “T” CELLS
During CMI response, some T-cells turn into MEMORY CELLS
FUNCTION
Memory cells protect the body in case of reaction in future.
TYPES OF IMMUNE RESPONSE
The immune system has also the ability to memorize the antigen it has encountered. Thus upon subsequent exposure to the same pathogen responds in two different ways.
1. Primary Immune Response
2. Secondary Immune Response
1. PRIMARY IMMUNE RESPONSE
DEFINITION
The first exposure to an antigen to the immune system elicits formation of clones of effectors cells to develop specific immunity with in 5 to 10 days. This response of immune system is termed as Primary Immune response.
CHARACTERISTICS
DELAYED APPEARANCE
WEAK POTENCY
SHORT LIFE
2. SECONDARY IMMUNE RESPONSE
DEFINITION
Subsequent exposure of same antigen causes a much more rapid & much more potent antibody response. This is called Secondary Immune response. It develops to it max. with in 3-5 days.
CHARACTERISTICS
Rapid & quicker appearance
Far more potent
Longer duration (form antibodies for many months rather than for only a few weeks.)
BASIS OF SECONDARY RESPONSE (IMMUNOLOGICAL MEMORY)
The quicker secondary response is made possible due to ability called “Immunological Memory” of the immune system. It is based upon the long lasting memory cells produced with short lived effectors cells of pri immune response. The development of memory cells may provide life long protection against some diseases like chicken pox.
ACTIVE & PASSIVE IMMUNITY
ACTIVE IMMUNITY
DEFINITION
The immunity which is acquired by own immune response is called active immunity
FUNCTION OF ACTIVE IMMUNITY
Active immunity due to development of immunological memory provide LONG TERM PROTECTION, even in some diseases (e.g in chicken Pox ) life long protection is provided.
TYPES OF ACTIVE IMMUNITY
There are two types.
1. Natural active immunity
2. Artificial active Immunity
1. NATURAL ACTIVE IMMUNITY
DEFINITION
When the active immunity is acquired as a consequence of natural infection then it is called Natural active immunity”
2. ARTIFICIAL ACTIVE IMMUNITY
DEFINITION
Active immunity can be acquired artificially by vaccination. In this case it is said to be “ARTIFICIAL ACTIVE IMMUNITY”
PASSIVE IMMUNITY
DEFINITION
Temporary immunity which is achieved in a person without injecting an antigen, by transferring the antibodies, activated T-cells or both obtain from another person or even an animal, is called passive immunity.
FUNCTIONS OF PASSIVE IMMUNITY
Although, acquired passive immunity is short lived (last for 2-3 weeks), it boosts the immune response of the victim several folds.
TYPES OF PASSIVE IMMUNITY
There are 2 Types:
1. Natural passive Immunity
2. Artificial passive Immunity
1. NATURAL PASSIVE IMMUNITY
DEFINITION
When antibodies are transferred from one person to another of the same species during natural processes, then such immunity is called Natural passive immunity.

EXAMPLE
A pregnant woman passes some of the antibodies to her fetus through placenta. The first breast feeding, the colostrum, of mother pass certain antibodies to her newly born infant.
2. ARTIFICIAL PASSIVE IMMUNITY
DEFINITION
PASSIVE IMMUNITY can also be transferred artificially by introducing antibodies derived from animals or human being who are already actively immunized to that disease. This is called artificial passive immunity.

EXAMPLE
RABIES is treated in man by injecting antibodies derided from persons who have been already vaccinated against rabies. This confers the rapid immunity to combat the rapidly progressing rabies in new victim.
IMMUNIZATION
The process of inducing immunity as a preventive measure against certain infectious diseases is called immunization.
ADVANTAGES OF IMMUNIZATION
The incidence of number of diseases (e.g Diptheria, Measles) has declined dramatically since the introduction of effective immunization programmes. Some dread full diseases (e.g. Tuberclosis) is now under control.
Posted by Kawish Hassan at 2:24 AM
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HUMAN HEART
INTRODUCTION
Heart, the most powerful organ in the circulatory system is conical, hollow & muscular organ, situated in middle mediastinum.
POSITION OF HEART
Heart lies in the thoracic cavity between the lungs slightly towards left, enclosed with in ribcage with the sternum in front & vertebral column behind.
SIZE & WEIGHT
The heart measures about 3 ½ Inches & weighs about 300 gm in males & 250 gm in females.
MAIN FUNCTION OF HEART
Heart works continuously like a muscular pump & pumps the blood to various parts of the body to meet their nutritive requirements.
COVERING OF HEART PERICARDIUM
Heart is surrounded by a double layered pericarcdium. The outer layer is called Fibrous pericardium & inner layer is called as serous pericardium.
PERICARDIAL FLUID
Fluid is secreted in b/w the two layers of pericardium which is known as pericardial fluid.
FUNCTION
Pericardial fluid acts as LUBRICANT & reduces friction b/w heart walls & surrounding tissues during beating of heart.
STRUCTURE OF HEART
Human heart consists of four chambers.
CHAMBERS OF HEART
1. RIGHT ATRIUM
Right Atrium is the right upper chamber of heart & acts as thin walled low pressure pump.
OPENINGS (INLETS) OF RIGHT ATRIUM
1. Superior Vena Cava
2. Anfenior Vena Cava
3. Coronary Sinus
FUNCTION
It receives venous blood from the whole body & pump it to the right ventricle through the right atrioventricular (tricuspid opening) valve.
2. LEFT ATRIUM
Left atrium is upper triangular chamber which is present posteriorly. It also acts as low pressure pump.
OPENINGS (INLETS) OF LEFT ATRIUM
Two pairs of pulmonary veins.
FUNCTION
It receives oxygenated blood from the lungs through 4 pulmonary veins and pumps it to the left ventricle through the left atrioventricular orifice (mitral or bicuspid).
3. RIGHT VENTRICLE
Right ventricle is the right lower chamber of heart, which is triangular in shape.
OPENINGS OF RIGHT VENTRICLE
Tricuspids valve
Pulmonary Aorta through pulmonary valve.
THICKNESS OF WALL
The wall of right ventricle is thinner than that of left ventricle in a ratio of 1:3
SIZE OF CAVITY
Cavity of right ventricle is broader than left because of thin muscular walls, and both of these features are due to the fact that right ventricle has to pump the blood into lungs only against low pressure system (i.e. pulmonary circulation).
FUNCTION
Right ventricle receives deoxygenated blood from right Atrium and pumps it to the lungs through pulmonary aorta for oxygenation.
4. LEFT VENTRICLE
Left ventricle is the most thick walled chamber and forms the apex of heart.
OPENING OF LEFT VENTRICLE
Bicuspid or Mitral valve
Systemic Aorta through aortic valve.
THICKNESS OF WALL
The walls of left ventricle are 3 times thicker than those of right ventricle. Blood pressure is 6 times high.
SIZE OF CAVITY
The cavity of left ventricle is narrower than the right ventricle because of more muscular walls. It is due to the fact that left ventricle has to pump the blood to the entire body against high pressure system (Systemic Circulation).
FUNCTION
It receives oxygenated blood from left atrium & pumps it into the aorta.
INTERNAL STRUCTURE OF VENTRLES
Interior of ventricles show two parts
1. Rough in flowing part
2. Smooth out flowing part
1. ROUGH PART
TRABECULAE CARNEAE
Inflowing part of each ventricle is rough due to presence of muscular ridges called as Trabeculae carneae.
2. SMOOTH PART
Out flowing part of each ventricle is smooth which gives origin to pulmonary trunk in right ventricle & Ascending Aorta in left ventricle.
PAPILLARY MUSCLES
Papillary muscles are the type of Trabeculae carneae being attached by their bases to ventricular walls, & their apices are connected to, the cusps of valves through chorda tendinae.
CHORDA TENDINAE:
These are delicate fibrous chords, which connect the papillary muscles to the cusps of Atriovertritcular valves.
FUNCTION
Chorda Tendinae don’t left the valves open back into the atria when the ventricles contract.
SEPTUM OF HEART
1. INTERATRIAL SEPTUM
Internally, the right & left atria are separated by a vertical membranous septum called as Interatrial septum.
2. INTERVENTRICULAR SEPTUM:
The right & left verticals are also separated by a thick muscular septum called as Interventricular septum.
3. ATRIOVENTRICULAR SEPTUM
Atria lie above & behind the ventricles & are separated from ventricles by Atrioven-tricular septum.
HEART VALVES
Heart possesses two types of valves, which regulate the flow of blood with in the heart.
TYPES OF HEART VALVES
1. Atrioventricular valves -> Bicuspid, Tricuspid
2. Semilunar vlaves -> Aortic valve, Pulmonary valve
1. ATRIOVENTRICULAR VALVES
INTRODUCTION
Valves, which are present in b/w the Atria & ventricles are called Atrioventricular valves.
TYPES OF ATRIOVENTRICULAR VALVES
They are of two types.
1. Bicuspid or Mitral
2. Tricuspid.
1. BICUSPID OR MITRAL VALVE
Blood flows from left Atrium to the left ventricle through left atrioventricular on orifice, which is guarded by bicuspid or Mitral valves.
CUSPS
It has tow (2) cusps so it is called as bicuspid.
2.TRICUSPID VALVE
Blood flows from right Atrium to the Right ventricle through right Atrioventricular orifice, which is guarded by Tricuspid.
CUSPS
It has 3 cusps so it is called as TRICUSPID.
2. SEMILUNAR VALVES
This is the second category of heart valves, which guard the emergence of pulmonary & systemic Aorta.
TYPES OF SEMILUNAR VALVES
It has Two Types:
1. Aortic Valve
2. Pulmonary Valve
1. AORTIC VALVE
This valve guards the Aortic orifice in left ventricle
CUSPS
It consists of 3 Semilunar cusps.
2. PULMONARY VALVE
This valve guards the pulmonary orifice in right ventricle.
CUSPS
It also consists of 3 semi lunar cusps.
FUNCTIONS OF VALVES
Heart valves maintain unidirectional flow of the blood & prevents its regurgitation in the opposite direction.
Posted by Kawish Hassan at 2:21 AM
1 comment:

Marc RasconTuesday, July 3, 2012 at 10:21:00 PM PDT
Thanks for this share and this collection of useful information. The circulatory system makes it sure that each and every body part of yours get proper circulation of blood. This particular system makes it a point that all the waste parts are cleared off in the most appropriate manner. Circulatory system ensures proper cleansing in the inners parts of your body especially in the body cells.

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CARDIAC CYCLE
Sequence of events which take pace during completion of one heart beat is called “Cardiac Cycle”
PHASES
(I) DIASTOLE
It is resting period of heart chambers.
II) SYSTOLE
During which heart’s chambers contract. In cardiac cycle, blood is circulated in whole body.
TYPES OF CIRCULATION
PULMONARY CIRCULATION
In pulmonary circulation following events take place.
RT. ATRIAL SYSTOL
First the blood from whole systems of body, except lungs enter in right Atrium through superior and Inferior vena cavae into the right atrium by atiral systole, blood comes into right ventricle from right atrium via Tricuspid valve.
RT. VENTRICLE SYSTOLE
After coming of blood into the Rt. Ventricle, it goes to the lungs via pulmonary trunk by ventricular systole, for oxygenation of blood by passing through pulmonary valve.
SYSTEMIC CIRCULATION
In systemic circulation, following events take place.
LEFT ATRIAL SYSTOLE
When oxygenated blood comes into left atrium, then left atrial sytole causes blood to enter left ventricle through bicuspid valve
LEFT VENTRICULAR SYSTOLE
When blood reaches here it sends into aorta through aortic valve to provide blood to body systems.
CARDIAC OUTPUT
The blood volume pump per minute by left ventricle into the systemic circulation
HEART BEAT
The contraction of heart chambers are known heart beat which are regular, rhythmic.
Ventricular systole is LUB
Ventricular diastole is DUB
TIME FOR HEART BEAT
0.8 sec is time for one heart beat.
CONDUCTING SYSTEM OF HEART
It consists of
1.AV-NODE
2.SA-NODE
3)AV-BUNDLE
4) PURKINJI FIBERS.
1. SA-NODE
SA NODE found near upper end of superior vena cava in RT. atrium
PARTS
1. Specialized cardiac Muscles.
2. Autonomic Nerve endings.
FUNCTIONS
It Initiates the contraction of heart chambers through impulses & also transmit to AV node.
2. AV- NODE
It is found in lower end of RT. Atrium. Structurally it is smilar to SA-NODE
FUNCTION
It transmit nerve impulses to ventricles for contraction rhythmically.
3. AV-BUNDLE
AV BUNDLE are the fibers originate from AV node. The bundle divided into Right AV bundle, Left AV bundle
FUNCTION
It transmit nerve impulses to ventricles.
4. PURKINJI FIBERS
AV bundles red divided into small fibres which penetrate the ventricle wall also known as purkinji fibers / Bundle of His small thin fibers.
LEUKEMIA
DEFINATION
“The malignant disorder of increase number of abnormal leucocytes in blood.”
CAUSE
The cause of leukemia is unknown.
FACTORS
Factors associated with leukemia are
Ionizing Radiation
Cytotoxic drugs.
Retroviruses.
Genetic
EFFECTS OF DISEASE
In result of leukemia, normal leucocytes counts become less.
This is progressive, and fatal condition which leads to heamorrhage or infection
THALASSEMIA
DEFINITION
“Genetically impaired globin chains formation leads to impaired or defected formation of hemoglobin.”
GENETIC DISEASE
Thalassemia is a genetic disorder, it may be
1. Hetrozygous /Mild thalassemia:
2. Homozygous.
TYPE
BETA – Thalassemia α – Thalassemia
BETA-THALASSEMIA
When globin chain is impaired or defected. It is most common one.
ALPHA-THALASSEMIA
when α-thalassemia globin chain of (HB) hemoglobin is defected.
KINDS OF THALASSEMIA
THALASSEMIA MINOR
When thalassemia is of heterozygous type with mild anemia.
THALASSEMIA MAJOR
When thalassemia is of homozygous type with profound hypochromic anemia. It is more common in children & results with enlargement of kidney.
REMEDY
The only remedy is transfusion of blood at regular intervals.
CVD CARDIOVASCULAR DISEASE
Diseases of heart, blood vessels and blood circulation are generally term as CVD.
ATHEROSCLEROSIS
The disease of arterial wall with lose of elasticity, thickness of inner wall causing narrowing of lumen, results in impairing of blood flow.
ATHEROMATOUS PLAQUES
The narrowing is due to formation of fatty lesions called atheromatous plaque in inner lining of arteries.
COMPONENTS OF PLAQUE
These plaques consist of
LDL-LOW DENSITY LIPO PROTEINS
DECAYING MUSCLES CELLS
FIBROUS TISSUE
PLATELETES
CLUMP OF BLOOD
CAUSES
Smoking, Hypertension, Obesity, Diabetes (Severe), family history of arterial disease
EFFECTS
Atherosclerosis produces no symptoms until the damage to artery is so severe that it restricts blood flow.
ANGINA PECTORIS
If blood flow to heart muscles is restricted causes (cell damage) necrosis called angina pectoris. Pain in chest, arm, or jaws usually during exercise.
THROMBUS FORMATION
The formation of blood clot with in the intact blood vessel initiated by atheromatous plaque.
REASON FOR THROMBUS FORMATION
Due to formation athromatous plaque loss of elasticity, intact blood vessel get destroyed, blood from vessel wall comes out & later change to blood clot and blocks the lumen of small arteries.
RESULT OF THROMBUS FORMATION
Initially thrombus block the lumen partially result in decrease blood flow to organs & leading to impairment of physiology of organs. Later on, thrombus blocks the lumen completely so due to complete loss of blood supply, cells damage occur.
CORONARY THROMBOSIS
Type of thrombosis when narrowing of lumen occurs in coronary blood vessels due to formation of clot.
EFFECT
Occulsion of coronary atery causes myocardial infarction and heart attack.
HEAMORRHAGE
The escaping of blood from intact blood vessels.
STROKE
Most dangerous type of heamorrhage is that of brain which results in paralysis or strokes.
HAEMATOMA
The accumalation of blood in interstitial spaces known as haematoma.
This will lead to edema.
STROKE
DEFINITION
The damage to the part of brain caused by, restriction in blood supply or leakage of blood outside the vessels.
CHARACTERISTICS
Impairment of sensation, movement & function controlled by damage part of brain.
CAUSES
Hypertension
Atherosclerosis
HEMIPLEGIA
Damage to any, one cerebral hemisphere can cause weakness or paralyses of one side of body called hemiplegia
PRECAUTIONARY MEASURES
Blood pressure should be with in normal range through proper diet. Salt should be used in less quantities exercise should be the regular habit. Smoking must be avoided. Person life should be free of worries.
BLOOD VESSELS
DEFINITION
“The closed vessels or tubes through which transporting medium or blood circulate with in body called “blood vessels”.
TYPES OF BLOOD VESSELS
1. Arteries.
2. Capillaries.
3. Veins.
ARTERIES
DEFINITION
Thick walled blood vessels which carry blood from heart to the organs of body.
LAYERS
It consists of three layers.
1. Tunica Externa/ Adventitia
2. Tunica Media
3. Tunica Intima
1-TUNICA EXTERNA
It is thin but tough layer, having abundant amount of collagen fibers. It is outer most layer.
2-TUNICA MEDIA
The middle layer has smooth muscle fibers & elastin fibers. It is the thickest layer.
3-TUNICA INTIMA
It consists of squamous endothelium.
LUMEN
Thick walled vessels & having smaller lumen than that of veins except arteries of brain & related to cranium having large lumen.
SEMILUNAR VALVES
They are not present in arteries.
BRANCHES – DIVISIONS
Aorta divides into large arteries, large arteries into smaller arteries, smaller arteries into arterioles, then they give rise to capillary.
At arteriole level, small sphincters are present which are known as PRE-CAPILLARY SPHINCTER.
SPHINCTER
FUNCTION
They are for regulating the diastolic pressure.
CHARACTERSTICS
Arteries are elastic so during systolic pressure, they do not rupture and dilate.
During ceasement/ stopage of systolic pressure of heart, arteries contract & supply even flow of blood.
The arteries carry oxygenated blood except pulmonary arteries.
VEINS
DEFINITION
The thin walled blood vessels that drian blood from body parts/organs into heart called veins.
LAYERS
Tunica Externa
Tunica Media
Tunica Intima
1. TUNICA EXTERNA
Thickest layer in veins. It contains collagen, elastin and smooth muscles cells.
2. TUNICA MEDIA
Not thicker as that of arteries. Elastic tissues and small smooth muscle.
3. TUNICA INTIMA
Contains endothelial cells layer.
LUMEN
It has large lumen and thin wall.
SEMILUNAR VALVES
They are present in veins to prevent back flow of blood in the influence of gravity.
TRIBUTARIES
Veninules -> small veins -> large veins -> vena cava.
BLOOD PRESSURE
In veins blood pressure is low and are non pulsatile.
CHARACTERISTICS
The blood flows slowly and smoothly in veins. Veins are superficial and collapse when empty.
CAPILARIES
The intimate microscopic closed channels of both arterial & veinous interconnected network is called capillaries.
DIAMETER
Capillaries are extremely narrow in diameter of about 7-10 μ.
LAYERS
Capillaries are thin walled vessels & contains single layer of endothelium which offers small resistance in transport of material across the capillary wall.
FUNCTION
Through diffusion and active transport of oxygen is transported to tissues & CO2 to capillaries. Nitrogenous waste is filtered through the capillaries into excretory tubules.
BLUE BABIES (CYANOSIS)
Blue baby is a layman terminology. In medical science it is known as cyanosis.
DEFINITION
The term cyanosis” means the blueish discolouration of the skin & mucous membrane due to excessive cone of reduced (deoxygenated haemoglobin) in the blood & it appears when reduced Hb conc in capillaries is more than 5 gm/dl of blood. The reduced Hb has an intense dark blue purple colour that is transmitted through the skin.
MOST COMMON CAUSE OF CYANOSIS
Although there are various other causes of cyanosis but the most common cause is CONGENITAL CYANOTIC HEART DISEASE.
BASIC CAUSE OF CYANOSIS
In congenital heart diseases, there is an abnormal connection b/w right and left side of heart, which permits the large amount of unoxygenated venous blood to bypass the pulmonary capillaries & dilute the oxygenated blood in systemic arteries i.e RIGHT TO LEFT SHUNT, which results in cyanosis.
SOME EXAMPLES OF CONGENITAL HEART DISEASES
Some congenital heart diseases which are responsible for the abnormal connection between right and left sides of heart are as follows.
ATRIAL SEPTUM DEFECT (ASD)
VENTRICULAR SETPUM DEFECT (VSD)
PERSISTANT DUCTUS ARTEROSUS
In all these conditions, blood begins to flow from the aorta (left side) into pulmonary arteries (right side) & the people donot show cyanosis until late in life when heart fails or lungs become congested.
TETRALOGY OF FALLOT (RIGHT –TO-LEFT SHUNT)
It is the most common cause of cyanosis or blue baby in which aorta originates from right ventricles rather than left & receives deoxygenated blood.
Posted by Kawish Hassa
http://all-notes.blogspot.com/2012/06/class-xi-biology-circulatory-system.html