Briefly describe the process of inflammation in an area that has been traumatized.
Inflammation is a non-specific defense mechanism of the body to tissue damage and occurs in 3 steps:
- Vasodilation and Increased Blood Permeability - More blood flow passes through the area and allows defensive proteins (antibodies, clotting factors) to enter the interstitial space and reach the injured area. This is caused by histamine, kinins, prostaglandins, leukotrienes, and complement.
- Emigration of Phagocytes - Neutrophils stick to the endothelium lining of the blood vessels and migrates to the injured area. These attempt to kill the bacteria via phagocytosis. After these die out, monocytes will continue to phagocytize bacteria until they die out as well.
- Tissue Repair - After the macrophages die out, a clot will form and tissue repair will begin.
Choose one type of Immunity (Innate and Humoral) and explain how its mechanism protects our body.
Humoral Immunity deals with millions of different B cells, each capable of responding to a specific antigen. Once activated, a B cell undergoes clonal selection that results in plasma cells and memory B cells. Plasma cells secrete antibodies after a few days after exposure to an antigen and targets bacteria that are extracellular (found in the blood stream). On the other hand, memory B cells do not secrete antibodies. Instead, they can quickly proliferate and differentiate into more plasma cells and more memory B cells should the same antigen reappear at a future time. Antibodies have several actions to fight infection which are neutralizing antigens, immobilizing bacteria, agglutinating and precipitating antigen, activating complement, and enhancing phagocytosis.