SCI 221 Final Exam V1 | SCI 221 Human
Physiology with Intervention Skill-Based
(ISB) Experiential Learning | Q&A with
Rationale (SCI221 Final Exam) |
Nightingale College
1. A patient is experiencing severe dehydration. Which hormone would you expect to be
significantly elevated in the blood to help conserve water?
A. Atrial Natriuretic Peptide (ANP)
B. Antidiuretic Hormone (ADH)
C. Oxytocin
D. Luteinizing Hormone
Correct Answer: B
Rationale: Antidiuretic hormone (ADH) is released by the posterior pituitary in response
to high plasma osmolarity or low blood volume. It acts on the collecting ducts of the
nephrons to increase water reabsorption by inserting aquaporins. This physiological
response is crucial for maintaining fluid balance and preventing further dehydration.
2. In the neuromuscular junction, what specific event triggers the release of acetylcholine
(ACh) into the synaptic cleft?
A. The binding of calcium to troponin
,B. The influx of sodium into the axon terminal
C. The movement of tropomyosin off the actin binding sites
D. The influx of calcium through voltage-gated channels
Correct Answer: D
Rationale: When an action potential reaches the axon terminal of a motor neuron, it opens
voltage-gated calcium channels. The resulting influx of calcium ions triggers the exocytosis
of synaptic vesicles containing acetylcholine. Acetylcholine then diffuses across the
synaptic cleft to bind with receptors on the motor end plate.
3. A person is frightened by a loud noise. Which division of the autonomic nervous system is
activated, and what is a primary physiological effect?
A. Parasympathetic; increased digestion
B. Somatic; voluntary muscle contraction
C. Parasympathetic; decreased heart rate
D. Sympathetic; pupillary dilation
Correct Answer: D
Rationale: The sympathetic nervous system is responsible for the ‘fight-or-flight’ response
during stressful or frightening situations. Activation leads to physiological changes such as
increased heart rate, bronchodilation, and pupillary dilation (mydriasis) to improve
, survival chances. These changes are mediated by the release of norepinephrine and
epinephrine from the adrenal medulla.
4. During the cardiac cycle, when does the majority of ventricular filling occur?
A. During atrial systole
B. During the passive filling phase of diastole
C. During the isovolumetric contraction phase
D. During the ventricular ejection phase
Correct Answer: B
Rationale: The majority of ventricular filling, approximately 70-80%, occurs passively
while both the atria and ventricles are in diastole. Atrial systole only contributes the final
20-30% of the end-diastolic volume, often called the ‘atrial kick.’ Understanding this phase
is vital for interpreting conditions like atrial fibrillation where the atrial kick is lost.
5. What is the primary function of the surfactant produced by Type II alveolar cells?
A. To increase the surface tension of the fluid in the lungs
B. To act as a primary barrier against bacterial infection
C. To facilitate the diffusion of CO2 out of the capillaries
D. To reduce the surface tension and prevent alveolar collapse
Correct Answer: D
Physiology with Intervention Skill-Based
(ISB) Experiential Learning | Q&A with
Rationale (SCI221 Final Exam) |
Nightingale College
1. A patient is experiencing severe dehydration. Which hormone would you expect to be
significantly elevated in the blood to help conserve water?
A. Atrial Natriuretic Peptide (ANP)
B. Antidiuretic Hormone (ADH)
C. Oxytocin
D. Luteinizing Hormone
Correct Answer: B
Rationale: Antidiuretic hormone (ADH) is released by the posterior pituitary in response
to high plasma osmolarity or low blood volume. It acts on the collecting ducts of the
nephrons to increase water reabsorption by inserting aquaporins. This physiological
response is crucial for maintaining fluid balance and preventing further dehydration.
2. In the neuromuscular junction, what specific event triggers the release of acetylcholine
(ACh) into the synaptic cleft?
A. The binding of calcium to troponin
,B. The influx of sodium into the axon terminal
C. The movement of tropomyosin off the actin binding sites
D. The influx of calcium through voltage-gated channels
Correct Answer: D
Rationale: When an action potential reaches the axon terminal of a motor neuron, it opens
voltage-gated calcium channels. The resulting influx of calcium ions triggers the exocytosis
of synaptic vesicles containing acetylcholine. Acetylcholine then diffuses across the
synaptic cleft to bind with receptors on the motor end plate.
3. A person is frightened by a loud noise. Which division of the autonomic nervous system is
activated, and what is a primary physiological effect?
A. Parasympathetic; increased digestion
B. Somatic; voluntary muscle contraction
C. Parasympathetic; decreased heart rate
D. Sympathetic; pupillary dilation
Correct Answer: D
Rationale: The sympathetic nervous system is responsible for the ‘fight-or-flight’ response
during stressful or frightening situations. Activation leads to physiological changes such as
increased heart rate, bronchodilation, and pupillary dilation (mydriasis) to improve
, survival chances. These changes are mediated by the release of norepinephrine and
epinephrine from the adrenal medulla.
4. During the cardiac cycle, when does the majority of ventricular filling occur?
A. During atrial systole
B. During the passive filling phase of diastole
C. During the isovolumetric contraction phase
D. During the ventricular ejection phase
Correct Answer: B
Rationale: The majority of ventricular filling, approximately 70-80%, occurs passively
while both the atria and ventricles are in diastole. Atrial systole only contributes the final
20-30% of the end-diastolic volume, often called the ‘atrial kick.’ Understanding this phase
is vital for interpreting conditions like atrial fibrillation where the atrial kick is lost.
5. What is the primary function of the surfactant produced by Type II alveolar cells?
A. To increase the surface tension of the fluid in the lungs
B. To act as a primary barrier against bacterial infection
C. To facilitate the diffusion of CO2 out of the capillaries
D. To reduce the surface tension and prevent alveolar collapse
Correct Answer: D
