...Essay Assignment – Unit 3 cont’d Urinary System A. Describe the structure of a kidney nephron and its associated blood vessels. * There are two parts of a kidney nephron; the renal corpuscle and the renal tubule. The renal corpuscle is the part of the kidney where the blood plasma is filtered and the renal tubule is the part of the nephron where the glomerular filtrate passes through after reaching the Bowman’s capsule. The renal corpuscle is made of the Bowman’s capsule and the glomerulus. In the glomerulus, there are capillaries located between the afferent arteriole and bring blood into the glomerulus and the efferent arteriole, which drains the blood away from the glomerulus. (IvyRose Holistic) There are cells that form the outer edges of the glomerulus and they form close attachments to cells of the inner surface of the glomerulus and these cells stick together and form a filtration membrane that would enable water and solutes to pass through the 1st wall of the Bowman’s capsule. * In the renal tubule, the first part of it is the Proximal Convoluted Tubule [PCT]. Solutes and water that have passed through the PCT would enter the Loop of Henlé and the water and the substances in it passes from the renal cortex and then into the renal medulla and then back to the cortex. The water and the substances dissolved in it returned to the renal cortex via the ascending limb of Henlé and then it passes through the Distal Convoluted Tubule [DCT]. The DCT converges onto...
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...Kidney is a bean-shaped organ and measures 10-12cm. Each kidney is covered by a dense irregular connective tissue capsule. Excretory systems regulate solute movement between internal fluids and the external environment. The kidney, the excretory organs of vertebrates is the mammal’s principal organ of excretion and osmoregulation. Osmoregulation regulates solute concentrations and balances the gain and loss of water. Thus, regulation of the osmotic concentrations of blood plasma by the kidneys ensures the osmotic regulation of all other body fluids. Excretion gets rid of many toxic metabolic waste products, particularly the nitrogenous compound urea. The mammalian excretory system centers on paired kidneys, which are also the principal site of water balance and salt regulation. Nephron is the functional unit of the vertebrate kidney approximately one million of nephrons can found in human kidney. Nephrons perform the function osmoregulation and excretion by filtration, reabsorption, secretion and excretion. Pressure-filtering of body fluids involve only filtration of most small molecules from blood plasma to form an ultrafiltrate of plasma. Selectively reabsorption by reclaiming valuable solutes like most of the water and other molecules from the ultrafiltrate and leaving behind waste material will be excreted. Secretion of hydrogen ion into the urine helps to maintain the acid-base balance. Excretion is to remove the metabolic waste products and unwanted chemicals or substances...
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...the wall of the nephron. The main sites where reabsorption occurs include proximal convoluted tubule, loop of Henle at the ascending and descending part and at the distal convoluted tubule. Secretions happen in the proximal convoluted tubule and in the distal convoluted tubule. Towards the end the collecting duct is where the excretion of unwanted substances takes place which goes down to the renal pelvis then leaving the kidneys via the ureter. Task 2 The Bowman’s capsule is a double walled epithelial cup, composed of tangled clusters of blood capillaries called glomerulus. The capsule is composed of two layers of cell: an inner layer that closely covers the glomerulus, and an outer layer. Plasma enters the glomerulus. There is an osmotic gradient in the glomerulus pushing fluid back in where there is also some fluid in Bowman’s capsule that opposes the flow of the filtrate into the Bowman’s capsule. However hydrostatic pressure overrides this and results in more pressure in glomerulus so the fluid flows into Bowman’s capsule. After this stage the fluid will flow into the proximal tubule. In the proximal convoluted tubule we reabsorb most of the materials that we need to reabsorb from the filtrate. The reabsorption of this material is called tubular reabsorption. The material is taken out of the filtrate by the cells that make up the tubules and sent into the interstitial fluid of the cortex or medulla. There is mitochondrion present in the cells as it produces ATP needed for active...
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...The Fantastic Voyage Part II Cynthia Gomez Hello everyone, we are back for another exciting adventure, this one a little more appetizing than the last! Today’s Fantastic Voyage will follow the path of one tasty hamburger, some fatty french fries, and a cold and sweet root beer through a fifty-five year old man’s digestive, circulatory and urinary systems. I will be narrating all structures and functions as we explore; some imagery may be a little graphic, so hold on tight if you have a weak stomach! Here we commence our journey straight into the mouth of our hungry friend, making our descent into the first part of this nine meter alimentary canal. Make sure to hold on tight, for this hollow chamber lined with mucous membranes like the rest of the digestive tract is where mechanical digestion takes place almost instantly. The teeth begin to chew the bites of food, breaking them down into smaller pieces while the salivary glands begin to secrete enzymes called salivary amylase to begin the chemical process of breaking down carbohydrates (Cleveland Clinic, 2014). Now that the carbohydrates from the hamburger, fries and root beer have begun to be digested, they have taken the shape of a moist bolus allowing it to pass through the rest of the tract with less friction. Now we are about to enter the pharynx, a tube-like structure made of muscle behind the nasal cavities and mouth. Together with the bolus, we quickly cross the...
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...PHYSIOLOGY QUESTIONS Diffusion refers to the process whereby molecules move from a high concentration to a low concentration across a semi-permeable membrane. DIFFUSION REFERS TO THE PROCESS WHEREBY SOLUTES MOVE FROM A HIGH CONCENTRATION TO A LOW CONCENTRATION ACROSS A SEMI-PERMEABLE MEMBRANE UNTIL EQUILIBRIUM IS REACHED. Osmosis is the diffusion of water from an area of low osmolarity to an area high osmolarity across a selectively permeable membrane. OSMOSIS REFERS TO THE DIFUSION OF WATER FROM AN AREA OF LOW OSMOLARITY TO AN AREA OF HIGH OSMOLARITY ACROSS A SELECTIVELY PERMEABLE MEMBRANE. Pinocytosis refers to a type of endocytosis, which involves the non-selective uptake of a sample of the extracellular fluid PINOCYTOSIS REFERS TO A TYPE OF ENDOCYTOSIS, WHICH INVOLVES THE NON-SELECTIVE UPTAKE OF A SAMPLE OF THE EXTRA-CELLULAR FLUID Phagocytosis refers to another type of endocytosis that involves the selective uptake of a multimolecular particle. PHAGOCYTOSIS REFERS TO ANOTHER TYPE OF ENDOCYTOSIS THAT INVOLVES THE SELECTIVE UPTAKE OF A MULTIMOLECULAR PARTICLE. A hypertonic solution refers to a solution with a high osmolarity, thus it refers to a solution that contains high solute concentration and a low water concentration. If a cell were placed within a hypertonic solution, water would move via osmosis from the cell to the solution. Osmosis would occur in this direction as osmosis refers to the diffusion of water from an area of low osmolarity, the cell...
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...1. Define the term excretion. .................................................................................................................................. .................................................................................................................................. [Total 2 marks] 2. The table below shows the mass of different substances excreted by a volunteer during two 24 hour periods. During the first 24 hour period, the volunteer was fed a protein-deficient diet; during the second 24 hour period, the volunteer was fed a protein-rich diet. All other variables were kept constant. mass of substance excreted / g substance excreted protein-deficient diet protein-rich diet urea 2.20 14.70 uric acid 0.09 0.18 ammonium ions 0.04 0.49 creatinine 0.60 0.58 (i) Calculate the percentage increase in urea excreted when the volunteer switched from a protein-deficient to a protein-rich diet. Show your working. Answer = ...................................................% [2] JFS School 1 (ii) Describe how excess protein is converted into urea. ......................................................................................................................... ......................................................................................................................... ..................................................................................................
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...1. Name the structure that arrow c is pointing to. A. glomerulus B. afferent arteriole @ C. peritubular capillaries D. efferent arteriole E. loop of Henle 2. Name the structure that arrow i is pointing to. A. glomerulus B. distal convoluted tubule @ C. peritubular capillaries D. efferent arteriole E. loop of Henle 3. Name the structure that arrow a is pointing to. A, glomerulus @ B. afferent arteriole C. peritubular capillaries D. efferent arteriole E. loop of Henle PLEASE REFER TO THE FOLLOWING DIAGRAM OF THE HUMAN DIGESTIVE SYSTEM TO ANSWER QUESTIONS 4-6. 4. Which structure transports food from the pharynx to the stomach? A. (arrow a) B. (arrow b) C. (arrow c) D. (arrow d) @ 5. Which structure produces bile? A. (arrow a) B. (arrow b) C. (arrow c) @ D. (arrow d) 6. Which structure is the place where almost all absorption of nutrients occurs? A. (arrow a) @ B. (arrow b) C. (arrow c) D. (arrow d) 7. The process by which food is propelled through the digestive tract by alternating contraction and relaxation of smooth muscle is: A. glycolysis B. plasmolysis C. emulsion D. peristalsis @ E. conjunctivitis 8. The organ in which the chemical digestion of fat molecules begins is the: A. stomach B. pancreas C. small intestine @ D. large intestine E. esophagus 9. The first portion of the small intestine is known as the: A. duodenum @ B. ileum C. colon D. cecum E. jejunum 10. Which of the following is not a structure that is part...
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...OVERVIEW OF KIDNEYS KIDNEY * (2) Fist-size * Around the belly button * Receive blood from the heart * Filter blood and release urine - collection of waste products that the body gets rid of WHAT KIDNEYS DO * Gets oxygenated blood vessel/artery * Artery – hold on to all the things in your blood 1. Nutrients – electrolytes, proteins, amino acid, glucose etc. 2. Oxygen 3. Waste products – through cellular respiration (urea, toxic compounds, extra electrolytes (Ex. sodium) * Too much nutrients -> waste products (helps make sure you don’t build too much good “stuff”) * Vein – takes the blood away from it take it back to the heart * Kidneys – nutrients are collected an maintained when collected in the vein * Oxygen - Some will get out, some will be used by the kidneys (maintain the tissue) - Less oxygen in the vein than in artery * Kidneys take waste products and hold on to it so it does not end up in venus outflow (produce urine) Kidney has 2 capillary beds – connects the artery and the vein (oxygen flow out, nutrients flow in) - Work together to deliver oxygen to the kidney’s tissue - Recollect nutrients so that the vein can take these nutrients elsewhere in the body 1. Vasa recta –give oxygen to kidneys 2. Peritubular capillaries – responsible for collecting nutrients that kidneys filter ------------------------------------------------- HOW DO OUR KIDNEYS FILTER WASTE OUT OF BLOOD * Kidneys...
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...Unit 9 Project – Fantastic Voyage HS130 - 04 June 19, 2012 Fantastic Voyage Good afternoon everyone! This is Lisa back again with another top health news story. Once again I will be taking my mini-sub through the miniaturization process making us only 8 microns long and traveling through the human body. Today we will be swallowed by a 55 year old man, Mr. Smith, who is currently eating a hamburger, French fries, and enjoying a nice cold root beer. Our goal today is to monitor the digestion of Mr. Smith’s meal through the gastrointestinal tract. As we progress through the body, I will be describing all the major structures that we go through as well as describing what happens to the meal as it goes through the digestion process. Let’s get started. We are going to begin our journey by watching how the food is digested via the gastrointestinal pathway and the urinary pathway. Starting with the digestive system, the food will begin to be digested in the mouth where food is acted upon by saliva and enzymes like amylase (WiseGeek, Digestive System, 2012). The brain has a reflex that triggers the flow of saliva into our mouths when we see or even think of food (WiseGeek, Digestive System, 2012). There are three major salivary glands that are involved in this process: the parotid, submandibular, and sublingual glands. These glands function to secrete saliva into our mouths in order to keep it moist, lubricate and bind our food to begin the digestion process, and...
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...dehydration is a loss of 10%-15% of body fluids. At this point, dehydration becomes a medical emergency. Jimmy was severely dehydrated and immediate steps were taken to rehydrate him. He was given intravenous fluids to restore his water and electrolytes that he had lost. What was happening in Jimmy’s body is that the osmolarity of his blood is higher than that of his tissues. This naturally causes water to be drawn from the cells and into the blood, since water follows a higher solute. (Where salt goes water follows.) The movement of water into the blood causes increases in blood volume, which increases blood pressure. Giving the blood enough pressure to pass though the glomerulus, the glomerulus is a capillary tuft surrounded by a Bowman’s capsule in the nephron of the kidneys. This is where your blood is filtered. If dehydration continues the tissues in the body start to die and the cells begin to shrivel. To maintain the homeostasis of the body’s water content or osmoregulation the body secretes a hormone called antidiurect hormone, ADH. ADH is secreted by part of the brain called the hypothalamus, located in an...
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...Environmental Health Perspectives Vol. 44, pp. 1-8, 1982 The Eye and Visual Nervous System: Anatomy, Physiology and Toxicology by Connie S. McCaa* The eyes are at risk to environmental injury by direct exposure to airborne pollutants, to splash injury from chemicals and to exposure via the circulatory system to numerous drugs and bloodborne toxins. In addition, drugs or toxins can destroy vision by damaging the visual nervous system. This review describes the anatomy and physiology of the eye and visual nervous system and includes a discussion of some of the more common toxins affecting vision in man. Anatomy of the Eyeball The eye consists of a retinal-lined fibrovascular sphere which contains the aqueous humor, the lens and the vitreous body as illustrated in Figure 1. The retina is the essential component of the eye and serves the primary purpose of photoreception. All other structures of the eye are subsidiary and act to focus images on the retina, to regulate the amount of light entering the eye or to provide nutrition, protection or motion. The retina may be considered as an outlying island of the central nervous system, to which it is connected by a tract of nerve fibers, the optic nerve. As in the case of the brain and the spinal cord, the retina is within two coats of tissue which contribute protection and nourishment. On the outside of the sphere, corresponding to the dura mater, a layer composed of dense fibrous tissue serves as a protective envelope, the fibrous...
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...The Importance of the Nephron in Kidneys All living organisms require a source of energy, usually in the form of food, to satisfy the cellular demands of the body and ultimately to sustain life. Thus, the nutrients that are consumed by organisms are broken down by various processes within organs, tissues, and cells, in order for important molecules, like minerals, vitamins, proteins, and carbohydrates, to be taken up and distributed around the body. The molecules not needed by the body or ends up as excess in the blood, is discarded as waste products; the system that is responsible for filtering our body, or rather our blood from these waste products, is known as the urinary system. The urinary system consists of organs in the body specific to filtering out excessive fluid and other substances from the bloodstream. This system works together with other organs like the lungs, skin, and intestines, all of which help with the process of eliminating wastes, and regulate the amount of chemicals and water floating in a person’s body (Campbell, “Excretory System”). In addition, these accessory systems to the urinary system ultimately help the body maintain pressure, volume, and composition of the blood (Campbell, “Excretory”). Along with electrolytes, uric acid, and glucose, the urinary system also removes a protein essential for breaking down proteins in the body which is called urea. Urea, together with water and other waste products, forms the liquid that is excreted from organisms...
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...Communication, Homeostasis & Energy Communication & Homeostasis Outline the need for communication systems within multicellular organisms, with reference to the need to respond to changes in the internal and external environment and to co-ordinate the activities of different organs. Organisms need to respond to external stimuli, e.g. temperature, oxygen concentration and levels of sunlight. These may be over time, e.g. winter fur to summer fur, or quickly, e.g. changing size of pupils. Internal environments change too- the build up of carbon dioxide as a result of respiration changes the pH of the tissue fluid, and therefore inhibits enzyme activity. Multicellular organisms need to coordinate different organs, so this requires a good communication system which will: • Cover the whole body • Enable cells to communicate with each other • Enable specific communication • Enable rapid communication • Enable both short and long-term responses. State that cells need to communicate with each other by a process called cell signalling. State that neuronal and hormonal systems are examples of cell signalling. Define the terms negative feedback, positive feedback and homeostasis. Negative feedback- A process in which any change in a parameter brings about the reversal of that change so that the parameter is kept fairly constant. Positive feedback- A process in which any change in a parameter brings about an increase in that change Homeostasis- The maintenance of a constant...
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...B3.1 The uninary system The urinary system is designed to remove waste products such as urea, as well as excess ions and water from our blood. The kidneys contain many nephrons which remove any waste, before reabsorbing any substances the body needs. Waste is stored in the bladder before being removed as urine. The urinary system overview Waste products are produced by our cells. These include carbon dioxide from respiration and urea from the breakdown of excess amino acids in the liver. Carbon dioxide is removed by our lungs. Our urinary system is responsible for producing, storing and removing urine from our bodies. Our urine contains urea and any excess water. The kidneys The kidneys are part of the urinary system, together with the ureter, urethra and bladder. Humans have two kidneys. They are bean-shaped organs - approximately 11.5 cm long – which are found just below our ribcage, one on either side of our spine. location of kidneys in abdominal cavity The renal arteries take blood with waste products to the kidneys to be filtered. Renal veins then return the filtered blood to be circulated around the body. Blood vessels take the blood though the kidneys where the waste products are removed into convoluted tubules. These tubules join together to form the ureter, which transports urine to the bladder where it is stored. Urine is then passed from the bladder to the urethra to be released. Kidney failure Since the kidney is responsible for the removal of waste...
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...the cell. Squamous cells are flat-like in appearance and are wider than tall. Cuboidal cells are similar in appearance to cubes. Columnar cells are taller than they are wide and have the appearance similar to columns. Lastly, Simple indicates one layer of cells and Stratified indicates numerous layers of cells. Simple Squamous Epithelium is the simplest of the epithelia and consist of a single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm. The function of these particular cells allows passage of materials by diffusion and filtration in sites where protection is not important. The cells secrete lubricating substances in serosae. Simple Squamous Epithelium cells are located in the lining of the Bowman’s capsule and the glomerulus of the kidney; air sacs of lungs; lining of heart, blood vessels, and...
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