BIOS 255 Exam 2 Questions and Answers with Rationales |
CHAMBERLAIN UNIVERSITY
Question 1. Which effect would most directly accompany severe disruption of lymphatic valve system?
A. transport of many absorbed long-chain dietary lipids would decrease
B. clearance of senescent red cells from blood would decrease
C. lymph would reflux and dependent tissue edema would become more likely
D. local mucosal immune responses would be less effective
Correct Answer: C. lymph would reflux and dependent tissue edema would become more likely
Explanation: The most direct consequence is that lymph would reflux and dependent tissue edema would become more
likely. That prediction follows because lymphatic valve system normally has this role: maintains one-way lymph flow
despite very low intraluminal pressure. The distractors reflect dysfunction of other structures or processes rather than the
most direct consequence here.
Question 2. Which observation would provide the strongest evidence of normal capillary hydrostatic
pressure function?
A. The system demonstrates that it pushes fluid out of capillaries into the interstitial space.
B. The system demonstrates that it provides rapid short-term stabilization of arterial pressure.
C. The system demonstrates that it is the peak arterial pressure reached during ventricular systole.
D. The system demonstrates that it pulls water into capillaries because plasma proteins are largely retained within
the vascular compartment.
Correct Answer: A. The system demonstrates that it pushes fluid out of capillaries into the interstitial space.
Explanation: The strongest evidence is the outcome linked to the normal role of capillary hydrostatic pressure: pushes
fluid out of capillaries into the interstitial space. This expected result depends on the mechanism that the pressure
gradient favors filtration, especially toward the arterial side of many capillary beds. The other outcomes would point to
different physiologic functions rather than intact capillary hydrostatic pressure activity.
Question 3. Which normal function best matches germinal center?
A. supports maturation and selection of T lymphocytes
B. filters blood by removing aged or damaged erythrocytes and serves as a reservoir for blood components
C. provides immune surveillance at mucosal surfaces that communicate with the external environment
D. supports proliferation and selection of activated B lymphocytes within a lymphoid follicle
Correct Answer: D. supports proliferation and selection of activated B lymphocytes within a lymphoid follicle
Explanation: The correct choice describes this function: supports proliferation and selection of activated B lymphocytes
within a lymphoid follicle. This is the primary role associated with germinal center, and it is supported by the
mechanism that antigen-stimulated B cells proliferate and undergo processes that improve the antibody response. The
other choices describe functions performed by different components within the same course domain.
,Question 4. Which option gives an internally consistent description of skeletal muscle pump?
A. It assists venous return by compressing veins during limb-muscle contraction; this is enabled because forward
pressure opens the cusps while reversed pressure fills them and closes the lumen.
B. It assists venous return by compressing veins during limb-muscle contraction; this is enabled because vasomotor
activity in the muscular wall adjusts regional resistance and flow.
C. It assists venous return by compressing veins during limb-muscle contraction; this is enabled because small
changes in radius create large changes in resistance, strongly influencing local flow and arterial pressure.
D. It assists venous return by compressing veins during limb-muscle contraction; this is enabled because muscle
contraction raises local venous pressure and propels blood toward the heart while valves prevent reversal.
Correct Answer: D. It assists venous return by compressing veins during limb-muscle contraction; this is enabled
because muscle contraction raises local venous pressure and propels blood toward the heart while valves prevent
reversal.
Explanation: The correct pairing links skeletal muscle pump to this role: assists venous return by compressing veins
during limb-muscle contraction, and to this mechanism: muscle contraction raises local venous pressure and propels
blood toward the heart while valves prevent reversal. A correct function paired with the wrong mechanism is still an
incorrect description. The other options deliberately mix the role of skeletal muscle pump with mechanisms that belong
to different components.
Question 5. Which finding most directly supports effective thymus function?
A. The system demonstrates that it filters blood by removing aged or damaged erythrocytes and serves as a reservoir
for blood components.
B. The system demonstrates that it supports maturation and selection of T lymphocytes.
C. The system demonstrates that it supports proliferation and selection of activated B lymphocytes within a
lymphoid follicle.
D. The system demonstrates that it absorbs dietary lipids from the small intestine into lymph.
Correct Answer: B. The system demonstrates that it supports maturation and selection of T lymphocytes.
Explanation: The strongest evidence is the outcome linked to the normal role of thymus: supports maturation and
selection of T lymphocytes. This expected result depends on the mechanism that immature T cells undergo
differentiation and selection before entering peripheral lymphoid tissues. The other outcomes would point to different
physiologic functions rather than intact thymus activity.
Question 6. Which paired feature-and-effect description is internally consistent for diastolic arterial
pressure?
A. Feature: it can follow major hemorrhage or severe fluid loss / Dysfunction: mean arterial pressure and coronary
perfusion conditions would change if this value changed markedly.
B. Feature: it is the blood pressure acting against the inside of the capillary wall / Dysfunction: mean arterial
pressure and coronary perfusion conditions would change if this value changed markedly.
C. Feature: stretch-sensitive receptors in the carotid sinus and aortic arch alter autonomic output when pressure
changes / Dysfunction: mean arterial pressure and coronary perfusion conditions would change if this value
changed markedly.
D. Feature: it corresponds to the lower number in a standard blood-pressure reading / Dysfunction: mean arterial
pressure and coronary perfusion conditions would change if this value changed markedly.
Correct Answer: D. Feature: it corresponds to the lower number in a standard blood-pressure reading /
Dysfunction: mean arterial pressure and coronary perfusion conditions would change if this value changed
markedly.
Explanation: For diastolic arterial pressure, the identifying feature is that it corresponds to the lower number in a
standard blood-pressure reading, and severe dysfunction would mean that mean arterial pressure and coronary perfusion
conditions would change if this value changed markedly. Both halves of the pairing must be correct for the option to be
valid. The distractors combine the correct consequence with a defining feature that belongs to another item.
, Question 7. A student is distinguishing closely related structures and processes. Which finding best
identifies lymphatic obstruction?
A. it appears as a pale central region in a secondary lymphoid follicle during an active immune response
B. it produces localized lymphedema downstream from blocked or removed lymphatic pathways
C. it is lymphoid tissue arranged around branches of the splenic arterial circulation
D. numerous valves divide collecting vessels into short functional segments
Correct Answer: B. it produces localized lymphedema downstream from blocked or removed lymphatic
pathways
Explanation: The identifying feature is that it produces localized lymphedema downstream from blocked or removed
lymphatic pathways. That characteristic is consistent with lymphatic obstruction and its normal role: causes protein-rich
interstitial fluid to accumulate when lymph drainage is inadequate. The other findings are characteristic of different
items and do not identify lymphatic obstruction as precisely.
Question 8. A student builds a causal chain for plasma colloid osmotic pressure. Which sequence is most
physiologically sound?
A. the pressure gradient favors filtration, especially toward the arterial side of many capillary beds -> therefore it
pulls water into capillaries because plasma proteins are largely retained within the vascular compartment.
B. elastic recoil and peripheral resistance maintain arterial pressure while the ventricle relaxes -> therefore it pulls
water into capillaries because plasma proteins are largely retained within the vascular compartment.
C. impermeant plasma proteins create an osmotic force that opposes filtration -> therefore it pulls water into
capillaries because plasma proteins are largely retained within the vascular compartment.
D. increased stretch raises afferent signaling and tends to reduce sympathetic drive while increasing
parasympathetic influence -> therefore it pulls water into capillaries because plasma proteins are largely retained
within the vascular compartment.
Correct Answer: C. impermeant plasma proteins create an osmotic force that opposes filtration -> therefore it
pulls water into capillaries because plasma proteins are largely retained within the vascular compartment.
Explanation: The sound causal chain begins with this mechanism: impermeant plasma proteins create an osmotic force
that opposes filtration. That mechanism allows plasma colloid osmotic pressure to fulfill the following role: pulls water
into capillaries because plasma proteins are largely retained within the vascular compartment. The other chains attach an
unrelated mechanism to the correct final role and therefore fail physiologically.
Question 9. Which effect would most directly accompany severe disruption of splenic red pulp?
A. clearance of senescent red cells from blood would decrease
B. rapid local expansion of activated B-cell clones would be reduced
C. transport of many absorbed long-chain dietary lipids would decrease
D. functional T-cell development would be impaired
Correct Answer: A. clearance of senescent red cells from blood would decrease
Explanation: The most direct consequence is that clearance of senescent red cells from blood would decrease. That
prediction follows because splenic red pulp normally has this role: filters blood by removing aged or damaged
erythrocytes and serves as a reservoir for blood components. The distractors reflect dysfunction of other structures or
processes rather than the most direct consequence here.
Question 10. Which feature is most characteristic of tunica intima?
A. it is the middle vessel layer and is especially thick in arteries
B. it is the outermost vascular layer and contains collagen-rich connective tissue
C. it generally has a larger lumen and thinner wall than a comparable artery
D. it is the layer directly contacting the blood and includes endothelium
Correct Answer: D. it is the layer directly contacting the blood and includes endothelium
CHAMBERLAIN UNIVERSITY
Question 1. Which effect would most directly accompany severe disruption of lymphatic valve system?
A. transport of many absorbed long-chain dietary lipids would decrease
B. clearance of senescent red cells from blood would decrease
C. lymph would reflux and dependent tissue edema would become more likely
D. local mucosal immune responses would be less effective
Correct Answer: C. lymph would reflux and dependent tissue edema would become more likely
Explanation: The most direct consequence is that lymph would reflux and dependent tissue edema would become more
likely. That prediction follows because lymphatic valve system normally has this role: maintains one-way lymph flow
despite very low intraluminal pressure. The distractors reflect dysfunction of other structures or processes rather than the
most direct consequence here.
Question 2. Which observation would provide the strongest evidence of normal capillary hydrostatic
pressure function?
A. The system demonstrates that it pushes fluid out of capillaries into the interstitial space.
B. The system demonstrates that it provides rapid short-term stabilization of arterial pressure.
C. The system demonstrates that it is the peak arterial pressure reached during ventricular systole.
D. The system demonstrates that it pulls water into capillaries because plasma proteins are largely retained within
the vascular compartment.
Correct Answer: A. The system demonstrates that it pushes fluid out of capillaries into the interstitial space.
Explanation: The strongest evidence is the outcome linked to the normal role of capillary hydrostatic pressure: pushes
fluid out of capillaries into the interstitial space. This expected result depends on the mechanism that the pressure
gradient favors filtration, especially toward the arterial side of many capillary beds. The other outcomes would point to
different physiologic functions rather than intact capillary hydrostatic pressure activity.
Question 3. Which normal function best matches germinal center?
A. supports maturation and selection of T lymphocytes
B. filters blood by removing aged or damaged erythrocytes and serves as a reservoir for blood components
C. provides immune surveillance at mucosal surfaces that communicate with the external environment
D. supports proliferation and selection of activated B lymphocytes within a lymphoid follicle
Correct Answer: D. supports proliferation and selection of activated B lymphocytes within a lymphoid follicle
Explanation: The correct choice describes this function: supports proliferation and selection of activated B lymphocytes
within a lymphoid follicle. This is the primary role associated with germinal center, and it is supported by the
mechanism that antigen-stimulated B cells proliferate and undergo processes that improve the antibody response. The
other choices describe functions performed by different components within the same course domain.
,Question 4. Which option gives an internally consistent description of skeletal muscle pump?
A. It assists venous return by compressing veins during limb-muscle contraction; this is enabled because forward
pressure opens the cusps while reversed pressure fills them and closes the lumen.
B. It assists venous return by compressing veins during limb-muscle contraction; this is enabled because vasomotor
activity in the muscular wall adjusts regional resistance and flow.
C. It assists venous return by compressing veins during limb-muscle contraction; this is enabled because small
changes in radius create large changes in resistance, strongly influencing local flow and arterial pressure.
D. It assists venous return by compressing veins during limb-muscle contraction; this is enabled because muscle
contraction raises local venous pressure and propels blood toward the heart while valves prevent reversal.
Correct Answer: D. It assists venous return by compressing veins during limb-muscle contraction; this is enabled
because muscle contraction raises local venous pressure and propels blood toward the heart while valves prevent
reversal.
Explanation: The correct pairing links skeletal muscle pump to this role: assists venous return by compressing veins
during limb-muscle contraction, and to this mechanism: muscle contraction raises local venous pressure and propels
blood toward the heart while valves prevent reversal. A correct function paired with the wrong mechanism is still an
incorrect description. The other options deliberately mix the role of skeletal muscle pump with mechanisms that belong
to different components.
Question 5. Which finding most directly supports effective thymus function?
A. The system demonstrates that it filters blood by removing aged or damaged erythrocytes and serves as a reservoir
for blood components.
B. The system demonstrates that it supports maturation and selection of T lymphocytes.
C. The system demonstrates that it supports proliferation and selection of activated B lymphocytes within a
lymphoid follicle.
D. The system demonstrates that it absorbs dietary lipids from the small intestine into lymph.
Correct Answer: B. The system demonstrates that it supports maturation and selection of T lymphocytes.
Explanation: The strongest evidence is the outcome linked to the normal role of thymus: supports maturation and
selection of T lymphocytes. This expected result depends on the mechanism that immature T cells undergo
differentiation and selection before entering peripheral lymphoid tissues. The other outcomes would point to different
physiologic functions rather than intact thymus activity.
Question 6. Which paired feature-and-effect description is internally consistent for diastolic arterial
pressure?
A. Feature: it can follow major hemorrhage or severe fluid loss / Dysfunction: mean arterial pressure and coronary
perfusion conditions would change if this value changed markedly.
B. Feature: it is the blood pressure acting against the inside of the capillary wall / Dysfunction: mean arterial
pressure and coronary perfusion conditions would change if this value changed markedly.
C. Feature: stretch-sensitive receptors in the carotid sinus and aortic arch alter autonomic output when pressure
changes / Dysfunction: mean arterial pressure and coronary perfusion conditions would change if this value
changed markedly.
D. Feature: it corresponds to the lower number in a standard blood-pressure reading / Dysfunction: mean arterial
pressure and coronary perfusion conditions would change if this value changed markedly.
Correct Answer: D. Feature: it corresponds to the lower number in a standard blood-pressure reading /
Dysfunction: mean arterial pressure and coronary perfusion conditions would change if this value changed
markedly.
Explanation: For diastolic arterial pressure, the identifying feature is that it corresponds to the lower number in a
standard blood-pressure reading, and severe dysfunction would mean that mean arterial pressure and coronary perfusion
conditions would change if this value changed markedly. Both halves of the pairing must be correct for the option to be
valid. The distractors combine the correct consequence with a defining feature that belongs to another item.
, Question 7. A student is distinguishing closely related structures and processes. Which finding best
identifies lymphatic obstruction?
A. it appears as a pale central region in a secondary lymphoid follicle during an active immune response
B. it produces localized lymphedema downstream from blocked or removed lymphatic pathways
C. it is lymphoid tissue arranged around branches of the splenic arterial circulation
D. numerous valves divide collecting vessels into short functional segments
Correct Answer: B. it produces localized lymphedema downstream from blocked or removed lymphatic
pathways
Explanation: The identifying feature is that it produces localized lymphedema downstream from blocked or removed
lymphatic pathways. That characteristic is consistent with lymphatic obstruction and its normal role: causes protein-rich
interstitial fluid to accumulate when lymph drainage is inadequate. The other findings are characteristic of different
items and do not identify lymphatic obstruction as precisely.
Question 8. A student builds a causal chain for plasma colloid osmotic pressure. Which sequence is most
physiologically sound?
A. the pressure gradient favors filtration, especially toward the arterial side of many capillary beds -> therefore it
pulls water into capillaries because plasma proteins are largely retained within the vascular compartment.
B. elastic recoil and peripheral resistance maintain arterial pressure while the ventricle relaxes -> therefore it pulls
water into capillaries because plasma proteins are largely retained within the vascular compartment.
C. impermeant plasma proteins create an osmotic force that opposes filtration -> therefore it pulls water into
capillaries because plasma proteins are largely retained within the vascular compartment.
D. increased stretch raises afferent signaling and tends to reduce sympathetic drive while increasing
parasympathetic influence -> therefore it pulls water into capillaries because plasma proteins are largely retained
within the vascular compartment.
Correct Answer: C. impermeant plasma proteins create an osmotic force that opposes filtration -> therefore it
pulls water into capillaries because plasma proteins are largely retained within the vascular compartment.
Explanation: The sound causal chain begins with this mechanism: impermeant plasma proteins create an osmotic force
that opposes filtration. That mechanism allows plasma colloid osmotic pressure to fulfill the following role: pulls water
into capillaries because plasma proteins are largely retained within the vascular compartment. The other chains attach an
unrelated mechanism to the correct final role and therefore fail physiologically.
Question 9. Which effect would most directly accompany severe disruption of splenic red pulp?
A. clearance of senescent red cells from blood would decrease
B. rapid local expansion of activated B-cell clones would be reduced
C. transport of many absorbed long-chain dietary lipids would decrease
D. functional T-cell development would be impaired
Correct Answer: A. clearance of senescent red cells from blood would decrease
Explanation: The most direct consequence is that clearance of senescent red cells from blood would decrease. That
prediction follows because splenic red pulp normally has this role: filters blood by removing aged or damaged
erythrocytes and serves as a reservoir for blood components. The distractors reflect dysfunction of other structures or
processes rather than the most direct consequence here.
Question 10. Which feature is most characteristic of tunica intima?
A. it is the middle vessel layer and is especially thick in arteries
B. it is the outermost vascular layer and contains collagen-rich connective tissue
C. it generally has a larger lumen and thinner wall than a comparable artery
D. it is the layer directly contacting the blood and includes endothelium
Correct Answer: D. it is the layer directly contacting the blood and includes endothelium
