verified correct detailed Answers Graded
A+ latest update 2025
16. What effect does the process of histamine binding to the
histamine-2 (H2) receptor have on inflammation?
a. Inhibition
b. Activation
c. Acceleration
d. Termination --- correct answers ---ANS: A
Binding histamine to the H2 receptor is generally antiinflammatory
because it results in the suppression of leukocyte function. Binding to
H2 receptors does not cause activation, acceleration, or termination of
the inflammatory process.
17. Frequently when H1 and H2 receptors are located on the same
cells, they act in what fashion?
a. Synergistically
b. Additively
,c. Antagonistically
d. Agonistically --- correct answers ---ANS: C
Both types of receptors are distributed among many different cells
and are often present on the same cells and may act in an antagonistic
fashion. For instance, neutrophils express both types of receptors,
with stimulation of H1 receptors resulting in the augmentation of
neutrophil chemotaxis and H2 stimulation resulting in its inhibition.
The two receptors do not act synergistically, additively, or
agonistically.
18. Some older adults have impaired inflammation and wound healing
because of which problem?
a. Circulatory system cannot adequately perfuse tissues.
b. Complement and chemotaxis are deficient.
c. Underlying chronic illness(es) exists.
d. Number of mast cells is insufficient. --- correct answers ---ANS: C
In some cases, impaired healing is not directly associated with aging,
in general, but can instead be linked to a chronic illness such as
cardiovascular disease or diabetes mellitus. Older adults may have
circulatory problems, but that would not lead directly to impaired
inflammation and wound healing. Older people do not have deficient
,complement and chemotaxis, nor do they have insufficient mast cell
numbers.
19. Which chemical mediator derived from mast cells retracts
endothelial cells to increase vascular permeability and to cause
leukocyte adhesion to endothelial cells?
a. Chemokines
b. Prostaglandin E
c. Platelet-activating factor
d. Bradykinin --- correct answers ---ANS: C
The biologic activity of platelet-activating factor is virtually identical
to that of leukotrienes; namely, it causes endothelial cell retraction to
increase vascular permeability, leukocyte adhesion to endothelial
cells, and platelet activation. The othe r options do not accurately
identify the chemical mediator derived from the process described in
the question. Chemokines function primarily to induce leukocyte
chemotaxis. Prostaglandins interact with the kinin system to
stimulate nerve endings and cause pain, among other actions.
Bradykinin is the most important product of the kinin system and
causes vascular permeability, smooth muscle contraction, and pain.
20. What is the inflammatory effect of nitric oxide (NO)?
, a. Increases capillary permeability, and causes pain
b. Increases neutrophil chemotaxis and platelet aggregation
c. Causes smooth muscle contraction and fever
d. Decreases mast cell function, and decreases platelet aggregation ---
correct answers ---ANS: D
Effects of NO on inflammation include vasodilation by inducing
relaxation of vascular smooth muscle, a response that is local and
short-lived, and by suppressing mast cell function, as well as platelet
adhesion and aggregation. NO does not increase capillary permeability
and cause pain, increase neutrophil chemotaxis and platelet
aggregation, or cause smooth muscle contraction and fever.
21. What is the correct sequence in phagocytosis?
a. Engulfment, recognition, fusion, destruction
b. Fusion, engulfment, recognition, destruction
c. Recognition, engulfment, fusion, destruction
d. Engulfment, fusion, recognition, destruction --- correct answers ---
ANS: C
Once the phagocytic cell enters the inflammatory site, the only correct
sequence of phagocytosis involves the following steps: (1)