satisfied to ensure successful infection in an individual host: • Sufficient virus must be available to initiate infection • Cells at the site of infection must be accessible, susceptible, and permissive for the virus • Local host anti-viral defense systems must be absent or initially ineffective. To infect its host, a virus must first enter cells at a body surface. Common sites of entry include the mucosal linings of the respiratory, alimentary, and urogenital tracts, the outer surface of the eye (conjunctival
Words: 5542 - Pages: 23
Gas exchange is a physical process by which gases enter and leave the body by diffusion (the movement of a substance from an area of high concentration to an area of low concentration) across gas exchange surfaces. Oxygen is extracted from the air and into the body, while carbon dioxide is released. Gas exchange is the diffusion of these gases into and out of cells, which is essential for respiration to occur. All living organisms respire. Cells need and use the energy that is formed through respiration
Words: 1103 - Pages: 5
the third day of development, the human egg or zygote it is now a small mass called the blastocyst. By 1-2 weeks the blastocyst’s inner cell mass separates into three layers. The Mesoderm is responsible for developing muscles, bones, blood, circulatory system, teeth, connective tissues and kidneys. The endoderm is responsible for the internal organs such as the stomach and intestine. And the ectoderm is responsible for things such as our skin, hair, sweat glands, salivary glands, brain, spinal cord
Words: 1361 - Pages: 6
Breathing, we do it subconsciously every day. The Respiratory system is responsible for this process to take place, the moment we do not breath our body begins to deteriorate, tissue, organs, begin to fail without vital oxygen. Most diseases that affect the respiratory system are deadly and must be taken very seriously. Our ability to breath must not be taken for granted. The Respiratory system is a vital part of the human body. It is responsible for the taking in and distribution of oxygen in the
Words: 1473 - Pages: 6
the respiratory system two ways, but still end up with its catastrophic results. One way is by smoking it; as the smoke enters the lung it is filtered and all of its harmful chemicals enter the bloodstream. Snorting in the other hand takes the powder into the nasal cavity and then is absorbed into the bloodstream. Smoking and inhaling meth can lead to a variety of respiratory problems just like cigarettes and marijuana like bronchitis, emphysema and lung
Words: 1327 - Pages: 6
PHASE II YEAR 1 COURSE: CARDIOVASCULAR SYSTEM ASSIGNMENT: CARDIAC TRANSPLANTATION Name: Asaad Saad Salman Date: 9/11/2015 Registration No.: 2014M045 Q1) Define the term "transplantation" and list the organs that can be transplanted. Transplantation is the process by which a dysfunctional organ is replaced by another healthy one. The other organ can be obtained from different sources, if from the same person (Autograft), if from another
Words: 766 - Pages: 4
Lymphatic System Functions House phagocytic cells and lymphocytes Important in body defense and disease resistance Collects excess water and proteins from intercellular fluid Transports fats from the GI tract into the blood stream Destroys microbes and foreign substances Cleanses blood of defective and old RBCs, WBCs, and platelets Lymph Tissues Lymph Vessels Meandering system of thin walled vessels Drains excess intercellular fluid and returns it to the circulatory system Lymph Nodes
Words: 1317 - Pages: 6
every cell of the body requires access to energy. However most cells are not able to travel to the energy source, ingested food. Therefore food must be converted to a serviceable form and delivered to the cells. To do this, the digestive system is a specialised system which ingests food, propels it through the gastrointestinal tract (GIT), digests it and absorbs the water, electrolytes and nutrients (1, 2). Once the beneficial substances
Words: 1608 - Pages: 7
held together, form tissue, the next main structure unit. Organs are collections of tissues that are combined to perform a particular function in the body. Organs do not work in isolation, however, and combine with other organs to create a biological system. Cells The cell is the most basic structural unit in the body. There are around 300 different cell types in the human body. While they differ in function, there are certain fundamental components or features that they generally have in common, such
Words: 1735 - Pages: 7
P4 Cardiovascular system The cardiovascular system is made up of blood vessels and your heart. The heart pumps oxygen and blood around your body allowing you to survive. It transports carbon dioxide which is a waste product from your body to your lungs. When you breathe out, carbon dioxide is removed from your body. Three main functions: Transportation - The system transports blood to most of the bodies tissues. In the blood there is special nutrients and oxygen which help us develop
Words: 1607 - Pages: 7
