Anatomy and Physiology Answer Key

Others can enter the phagocytes completely filling

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Unformatted text preview: s. (c) Tissue repair. Role: Replaces damaged cells and tissues, restoring the integrity of the area. 2. Ability to squeeze through capillary walls (amoeboid movement). Ability to engulf material by phagocytosis. 3. Histamines and prostaglandins attract phagocytes to the site of infection. 4. Pus is the accumulated debris of infection (dead phagocytes, damaged tissue, and fluid). It accumulates at the site of infection where the defense process is most active. Fever (page 136) 1. The high body temperature associated with fever intensifies the action of interferon (a potent antiviral substance). Fever also increases metabolism, which is associated with increased blood flow. These changes increase the rate at which white blood cells are delivered to the site of infection and help to speed up the repair of tissues. The release of interleukin-1 during fever helps to increase the production of T cell lymphocytes and speeds up the immune response. 2. 1: 2: With few T cells, the body lacks an effective cell mediated immune system and responds poorly to opportunistic pathogens that get past the first defenses. Blood Clotting and Defense (page 133) 1. (a) Prevents bleeding and invasion of bacteria. (b) Aids in the maintenance of blood volume. 2. (a) Injury exposes collagen fibers to the blood. (b) Chemicals make the surrounding platelets sticky. (c) Clumping forms an immediate plug of platelets preventing blood loss. (d) Fibrin clot traps red blood cells and reinforces the seal against blood loss. (a) Clotting factors catalyze the conversion of prothrombin to thrombin, the active enzyme that catalyzes the production of fibrin. (b) If clotting factors were always present, clotting could not be contained; blood would clot when it shouldn’t. 3. (a) and (b) provided below. The first is the obvious answer, but there are disorders associated with the absence of each of the twelve clotting factors: (a) Classic hemophilia (b) Clotting factor VIII (anti-hemophilic factor) (a) Hemophilia B (Christmas disease) (b) Clotting factor IX (...
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This document was uploaded on 01/28/2014.

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