Immune System and Highly Organized Centers free essay sample

Redness, selling, pain and heat. Redness is caused by dilation of the blood vessels at the site of injury. Heat results from increased blood flow through the area. Fever is brought on by chemical mediators of inflammation and contributes to the rise in temperature at the site. Edema is caused by the accumulation of fluid outside the blood vessels. 2. Neutrophils are attracted to the site by a process of chemotaxis. Chemotaxis is where cytokines are released at the point of infection by the infected cells also by the compliment cascade. Neutrophils are capable of combating infection in a number of ways, primarily they are able to phagocytize and digest pathogens. They can secrete a number of antibacterial chemicals at the site of infection including lactoferin and cathelicidin. Opsinization is a process carried out by compliment which makes pathogens easier to phagocytize. Roughly translated, opsinize means to prepare to eat. This process is particularly important for the phagocytosis of encapsulated bacteria. We will write a custom essay sample on Immune System and Highly Organized Centers or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page 3. Lymph nodes, in conjunction with the spleen, tonsils, adenoids, Peyers Patches are highly organized centers of immune cells that filter antigen from the extracellular fluid. 4. Tonsils are a pair of soft tissue masses located at the rear of the throat. Each is composed of tissue similar to lymph nodes, covered by pink mucosa. Running through the mucosa of each tonsil are pits called crypts. Tonsils are part of the lymphatic system which helps fight infection. 5. Fever is a positive feedback mechanism which acts towards the direction of change. Fever is opposite of thermoregulation. Substances which induce fever are called pyrogens. Although external pathogens may be the ultimate reason for a fever, it is the internal or endogenous pyrogens that directly cause the increase in the thermoregulatory set-point. 6. WBC are circulating in the blood. An increase in circulating WBC’s, referred to as leukocytosis, can result from several causes IE: certain drugs, leukemia, inflammation, autoimmune disease, allergic response, hyperthyroidism, sarcoidism.