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(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.
- Winter '13