Immune System and Classical Pathway
The alternative pathway is when C3 and factors B,D, and P interact on the surface of the pathogen and C3 is again turned on and at this point it is split into C3a and C3b. When C3b binds to the pathogen the inflammation we all know and love becomes present. Fever is a response by the neurons in the hypothalamus in response to pyrogens which are secreted by macrophages and leukocytes. Pain is caused by the swelling of the area in question as the nerves are being pressed and toxins affecting the area. 2.
The exudate on Jason’s tonsils consisted primarily of neutrophils, and the CBC that was performed indicated that the number of neutrophils in his circulation was increased. What role do neutrophils play in the resolution of a bacterial infection? In the course of your answer explain terms such as adhesion molecules, diapedesis, chemotaxsis, opsonization, and phagocytosis. White blood cells are induced by factors which are released when tissue is injured and white blood cells phagocytize the pathogen.
The inflamed tissues releases cell adhesion molecules which slow down the WBC’s so they can adhere to the pathogen in a process called margination. When they flatten and go through the capillary wall diapedesis is said to have occurred. Chemotaxsis is where the phagocytic agents follow their noses so to speak to where the inflammation began. 3. Jason’s physician noted that Jason’s cervical lymph nodes were enlarged, a condition referred to as lymphadenopathy. Describe the structure and function(s) of lymph nodes, and list the other organs and tissues that comprise the lymphatic system.
The major organs of the lymph system are tonsils, , thymus, spleen with minor ones in the neck, pelvis, inquinals and low back and arise from bone marrow and depending on where they reside will depend on what type of immunity in conferred but all is made by the use of gene fragments to help develop antigen receptors. 4. Describe the anatomic location and function of tonsils. The tonsils are lymphoid tissue, which are found at the back of the mouth and the back of the throat. They form the first line of defense against airborne organisms.
Bacteria and viruses in the air pass through the nose or the mouth. They are then carried to the tonsils and the adenoids, where they can multiply and cause inflammation. White blood cells are attracted to the area to combat the organisms, and cause the swelling and sore throat that accompany infection of the glands. Continued infection causes swelling of the lymph nodes in the neck. 5. What is the mechanism by which fever is induced and what are its benefits in terms of combating an infection? Fever is a systemic response to invading organisms.
The thymus resets upward in response to pyrogens which are secreted by WBC’s and other macrophages that have been exposed to pathogens. The benefits is that the body holds on the vital nutrients that the pathogens need to survive and decreased the metabolism which enhances the repair process. 6. What is the mechanism by which the number of circulating white blood cells is increased? Leukocytosis is a response to the release of chemicals called leukocytosis –inducing factors. The white blood cells will increase four –five time the usual number and is a good indicator of infection.