,CONTENT
Chapter 1 Medical Physiology: An Overview
Chapter 2 Cell Signaling, Membrane Transport, and Membrane Potential
Chapter 3 Action Potential, Synaptic Transmission, and Nerve Function
Chapter 4 Sensory Physiology
Chapter 5 Motor System
Chapter 6 Autonomic Nervous System
Chapter 7 Integrative Functions of the Central Nervous System
Chapter 8 Skeletal and Smooth Muscle
Chapter 9 Blood Composition and Function
Chapter 10 Immunology, Organ Interaction, and Homeostasis
Chapter 11 Overview of the Cardiovascular System and Hemodynamics
Chapter 12 Electrical Activity of the Heart
Chapter 13 Cardiac Muscle Mechanics and the Cardiac Pump
Chapter 14 The Systemic Circulation
Chapter 15 Microcirculation and Lymphatic System
Chapter 16 Special Circulations
Chapter 17 Control Mechanisms in Cardiovascular Function
Chapter 18 Ventilation and the Mechanics of Breathing
Chapter 19 Gas Transfer and Transport
Chapter 20 Pulmonary Circulation and Ventilation/Perfusion
Chapter 21 Control of Ventilation
Chapter 22 Kidney Function
Chapter 23 Regulation of Fluid and Electrolyte Balance
Chapter 24 Acid–Base Homeostasis
Chapter 25 Gastrointestinal System Functions
Chapter 26 Liver Functions and Immune Surveillance
Chapter 27 Motility and Gastrointestinal Regulation
Chapter 28 Regulation of Body Temperature
Chapter 29 Exercise Physiology
Chapter 30 Endocrine Control Mechanisms
Chapter 31 Hypothalamus and the Pituitary Gland
Chapter 32 Thyroid Gland
Chapter 33 Adrenal Gland
Chapter 34 Endocrine Pancreas
Chapter 35 Endocrine Regulation of Calcium, Phosphate, and Bone Homeostasis
Chapter 36 Male Reproductive System
Chapter 37 Female Reproductive System
Chapter 38 Fertilization, Pregnancy, and Fetal Development
,Chapter 1 — Medical Physiology: An Overview
Test Bank questions where each question aligns with the chapter, four options (A–
D), Correct answer shown followed by a deep rationale and a short list of key
words.
1. Which statement best captures the role of physiology in clinical medicine?
A. Physiology is primarily concerned with cataloguing normal anatomy for
surgeons.
B. Physiology studies isolated molecular events and has limited relevance to
patient care.
C. Physiology provides mechanistic, multiscale (molecule → cell → organ →
system) explanations of function that form the foundation for understanding
pathophysiology, diagnosis, and therapy.
D. Physiology’s main use is to define population reference ranges for laboratory
values.
Answer: C
Rationale: Physiology links molecular mechanisms to organ-level function and
whole-body responses; it is the conceptual base for interpreting how perturbations
produce signs/symptoms and for rational interventions (e.g., how reduced cardiac
contractility leads to fluid retention and targeted use of diuretics/vasodilators).
Reference ranges are useful, but mechanistic understanding guides diagnosis and
treatment.
Keywords: integrative physiology, mechanism → clinical translation,
pathophysiology.
2. Which statement most accurately distinguishes a biological steady state from
thermodynamic equilibrium?
A. At equilibrium there are no gradients and no net energy exchange; at steady
state gradients can persist but require continuous energy input to maintain.
B. At steady state there are no gradients and it requires no energy input; at
equilibrium gradients persist and require energy.
C. Steady state and equilibrium are interchangeable terms in physiology.
,D. Both steady state and equilibrium always require energy input to maintain.
Answer: A
Rationale: Physiologic variables (body temperature, ionic gradients) are often
stable yet maintained by metabolic energy — a steady state. Thermodynamic
equilibrium implies no net fluxes and no required energy input (rare in living
systems). Understanding this distinction clarifies why cells expend energy
continuously (e.g., Na⁺/K⁺-ATPase) to maintain function.
Keywords: steady state, equilibrium, energy input, gradients.
3. A patient with a sudden rise in arterial pressure demonstrates reflex bradycardia
and reduced sympathetic tone. This response is best classified as:
A. Negative feedback (baroreceptor reflex) that minimizes deviation from set
point.
B. Positive feedback that amplifies the pressure rise.
C. Feedforward control preparing the heart for anticipated changes.
D. An example of homeostatic failure.
Answer: A
Rationale: The baroreceptor reflex detects arterial stretch (sensor), transmits
afferent signals to brainstem (comparator/controller), and triggers efferent changes
(reduced sympathetic, increased parasympathetic) that lower heart rate and
vascular resistance — classic negative feedback that opposes the perturbation.
Keywords: baroreceptor, negative feedback, homeostasis, reflex arc.
4. Which of the following is the best example of physiological positive feedback?
A. Insulin secretion rising as blood glucose increases to restore normoglycemia.
B. Stretch reflex in maintaining posture.
C. Baroreflex response to elevated arterial pressure.
D. Oxytocin release during uterine contractions that intensifies contractions until
delivery.
Answer: D
Rationale: Positive feedback amplifies a process — oxytocin release increases
uterine contractions, which increases oxytocin secretion, continuing until a
terminating event (delivery) ends the cycle. Insulin and baroreflex are negative
feedback; stretch reflex is a local reflex stabilizing muscle length.
Keywords: positive feedback, oxytocin, parturition, amplification.
,5. In a physiologic negative-feedback control system, increasing the system gain
(controller responsiveness) generally results in:
A. Greater steady-state error and improved stability.
B. Always more stability and no change in steady-state error.
C. Reduced steady-state error but increased risk of oscillation or instability if gain
is excessive.
D. A shift in the set point of the controlled variable.
Answer: C
Rationale: Gain is the ratio of corrective output to error. High gain improves
tracking (smaller steady-state error) but can lead to overshoot and oscillations
(instability). Clinically, “loop gain” concept explains phenomena such as Cheyne–
Stokes breathing and central sleep apnea — high loop gain predisposes to periodic
breathing. Set point is separate.
Keywords: gain, stability, oscillation, loop gain, Cheyne-Stokes.
6. Which of these best exemplifies feedforward control in human physiology?
A. Cephalic-phase insulin release triggered by sight/smell of food that lowers
postprandial glucose excursions.
B. Renal retention of sodium in response to decreased arterial pressure.
C. Baroreflex responses to an acute hemorrhage.
D. Fever produced by hypothalamic set-point elevation.
Answer: A
Rationale: Feedforward control anticipates a disturbance and acts before the
controlled variable changes. The cephalic insulin response prepares tissues for
incoming glucose, reducing postprandial peaks. Baroreflex and renal retention are
feedback; fever is a set-point change (feedback with altered comparator).
Keywords: feedforward, cephalic phase, anticipatory control, insulin.
7. Fever during infection occurs because pyrogens increase the hypothalamic set
point. The principal adaptive advantage of a moderately elevated body temperature
is:
A. It increases basal metabolic efficiency in stressed tissue.
B. It enhances certain immune functions and reduces replication rates of some
pathogens.
,C. It primarily protects against circulatory collapse.
D. It is solely a maladaptive side effect of infection.
Answer: B
Rationale: Pyrogens (endogenous e.g., IL-1, TNF → PGE₂) raise the
thermoregulatory set point. Moderate fever can enhance leukocyte mobility,
antigen presentation, and impair replication of some microbes. However, extremes
are harmful; antipyretics act via PGE₂ inhibition (e.g., NSAIDs).
Keywords: fever, PGE₂, pyrogens, immune enhancement, set point.
8. An example of redundancy in physiological regulation (multiple mechanisms
serving the same function) is:
A. A single hepatic enzyme that converts all toxic compounds.
B. Erythropoietin being produced exclusively in the liver.
C. Blood pressure regulation via baroreceptor reflex, renin–angiotensin–
aldosterone system (RAAS), and pressure natriuresis by the kidney.
D. Tidal volume controlled only by the medullary respiratory center with no other
inputs.
Answer: C
Rationale: Redundancy means multiple overlapping mechanisms maintain a
critical function (blood pressure). If one mechanism fails or is stressed, others
compensate, conferring robustness. Understanding redundancy explains why
single-target failures often do not immediately produce collapse but chronic stress
can overwhelm multiple systems.
Keywords: redundancy, RAAS, baroreflex, pressure natriuresis, robustness.
9. Regarding acid–base compensation: which statement correctly describes relative
timing of respiratory vs renal compensation?
A. Renal compensation occurs within seconds, while respiratory compensation
takes days.
B. Respiratory compensation is rapid (minutes) and renal compensation is slow
(hours–days).
C. Both renal and respiratory compensations occur within minutes.
D. Neither system has any compensatory capacity; only buffers work.
Answer: B
Rationale: Ventilatory adjustments alter arterial CO₂ within minutes (rapid), while
renal adjustments (H⁺ secretion, HCO₃⁻ reclamation/generation) require hours to
, days to change plasma bicarbonate substantially. Immediate intracellular buffers
act quickly but are limited. Clinical interpretation of ABGs relies on timing.
Keywords: compensation, respiratory (minutes), renal (hours–days), buffers.
10. A patient with autonomic failure stands up and experiences profound
orthostatic hypotension with little compensatory tachycardia. Physiologically, this
occurs because:
A. Venous return increases on standing and the autonomic system overreacts.
B. The heart rate increases excessively due to hypersensitive baroreceptors.
C. Sympathetic efferent responses are impaired so vasoconstriction and heart-rate
increases are inadequate.
D. The kidneys acutely increase sodium excretion causing hypovolemia.
Answer: C
Rationale: On standing blood pools in the legs → decreased venous return →
lower stroke volume. Normally baroreflex increases sympathetic tone
(vasoconstriction, HR) to restore pressure. In autonomic failure the efferent
sympathetic response is blunted, so compensation fails, causing hypotension and
syncope.
Keywords: orthostatic hypotension, autonomic failure, baroreflex efferent.
11. Circadian modulation of homeostatic set points is best explained by which
mechanism?
A. Suprachiasmatic nucleus (SCN) orchestrating daily rhythms through neural and
hormonal outputs (e.g., HPA axis contributing to morning cortisol peak).
B. Circadian rhythms are only a property of peripheral tissues and not centrally
coordinated.
C. Hormones such as cortisol are secreted at steady constant rates and do not
follow circadian patterns.
D. Light and behavioral cues do not entrain physiological rhythms.
Answer: A
Rationale: The SCN acts as the central pacemaker, entrained by light, and
coordinates peripheral clocks and hormonal rhythms (cortisol peaks before
waking). This circadian modulation influences metabolism, temperature, and drug
pharmacodynamics/chronotherapy.
Keywords: circadian, SCN, HPA axis, cortisol peak, entrainment.
Chapter 1 Medical Physiology: An Overview
Chapter 2 Cell Signaling, Membrane Transport, and Membrane Potential
Chapter 3 Action Potential, Synaptic Transmission, and Nerve Function
Chapter 4 Sensory Physiology
Chapter 5 Motor System
Chapter 6 Autonomic Nervous System
Chapter 7 Integrative Functions of the Central Nervous System
Chapter 8 Skeletal and Smooth Muscle
Chapter 9 Blood Composition and Function
Chapter 10 Immunology, Organ Interaction, and Homeostasis
Chapter 11 Overview of the Cardiovascular System and Hemodynamics
Chapter 12 Electrical Activity of the Heart
Chapter 13 Cardiac Muscle Mechanics and the Cardiac Pump
Chapter 14 The Systemic Circulation
Chapter 15 Microcirculation and Lymphatic System
Chapter 16 Special Circulations
Chapter 17 Control Mechanisms in Cardiovascular Function
Chapter 18 Ventilation and the Mechanics of Breathing
Chapter 19 Gas Transfer and Transport
Chapter 20 Pulmonary Circulation and Ventilation/Perfusion
Chapter 21 Control of Ventilation
Chapter 22 Kidney Function
Chapter 23 Regulation of Fluid and Electrolyte Balance
Chapter 24 Acid–Base Homeostasis
Chapter 25 Gastrointestinal System Functions
Chapter 26 Liver Functions and Immune Surveillance
Chapter 27 Motility and Gastrointestinal Regulation
Chapter 28 Regulation of Body Temperature
Chapter 29 Exercise Physiology
Chapter 30 Endocrine Control Mechanisms
Chapter 31 Hypothalamus and the Pituitary Gland
Chapter 32 Thyroid Gland
Chapter 33 Adrenal Gland
Chapter 34 Endocrine Pancreas
Chapter 35 Endocrine Regulation of Calcium, Phosphate, and Bone Homeostasis
Chapter 36 Male Reproductive System
Chapter 37 Female Reproductive System
Chapter 38 Fertilization, Pregnancy, and Fetal Development
,Chapter 1 — Medical Physiology: An Overview
Test Bank questions where each question aligns with the chapter, four options (A–
D), Correct answer shown followed by a deep rationale and a short list of key
words.
1. Which statement best captures the role of physiology in clinical medicine?
A. Physiology is primarily concerned with cataloguing normal anatomy for
surgeons.
B. Physiology studies isolated molecular events and has limited relevance to
patient care.
C. Physiology provides mechanistic, multiscale (molecule → cell → organ →
system) explanations of function that form the foundation for understanding
pathophysiology, diagnosis, and therapy.
D. Physiology’s main use is to define population reference ranges for laboratory
values.
Answer: C
Rationale: Physiology links molecular mechanisms to organ-level function and
whole-body responses; it is the conceptual base for interpreting how perturbations
produce signs/symptoms and for rational interventions (e.g., how reduced cardiac
contractility leads to fluid retention and targeted use of diuretics/vasodilators).
Reference ranges are useful, but mechanistic understanding guides diagnosis and
treatment.
Keywords: integrative physiology, mechanism → clinical translation,
pathophysiology.
2. Which statement most accurately distinguishes a biological steady state from
thermodynamic equilibrium?
A. At equilibrium there are no gradients and no net energy exchange; at steady
state gradients can persist but require continuous energy input to maintain.
B. At steady state there are no gradients and it requires no energy input; at
equilibrium gradients persist and require energy.
C. Steady state and equilibrium are interchangeable terms in physiology.
,D. Both steady state and equilibrium always require energy input to maintain.
Answer: A
Rationale: Physiologic variables (body temperature, ionic gradients) are often
stable yet maintained by metabolic energy — a steady state. Thermodynamic
equilibrium implies no net fluxes and no required energy input (rare in living
systems). Understanding this distinction clarifies why cells expend energy
continuously (e.g., Na⁺/K⁺-ATPase) to maintain function.
Keywords: steady state, equilibrium, energy input, gradients.
3. A patient with a sudden rise in arterial pressure demonstrates reflex bradycardia
and reduced sympathetic tone. This response is best classified as:
A. Negative feedback (baroreceptor reflex) that minimizes deviation from set
point.
B. Positive feedback that amplifies the pressure rise.
C. Feedforward control preparing the heart for anticipated changes.
D. An example of homeostatic failure.
Answer: A
Rationale: The baroreceptor reflex detects arterial stretch (sensor), transmits
afferent signals to brainstem (comparator/controller), and triggers efferent changes
(reduced sympathetic, increased parasympathetic) that lower heart rate and
vascular resistance — classic negative feedback that opposes the perturbation.
Keywords: baroreceptor, negative feedback, homeostasis, reflex arc.
4. Which of the following is the best example of physiological positive feedback?
A. Insulin secretion rising as blood glucose increases to restore normoglycemia.
B. Stretch reflex in maintaining posture.
C. Baroreflex response to elevated arterial pressure.
D. Oxytocin release during uterine contractions that intensifies contractions until
delivery.
Answer: D
Rationale: Positive feedback amplifies a process — oxytocin release increases
uterine contractions, which increases oxytocin secretion, continuing until a
terminating event (delivery) ends the cycle. Insulin and baroreflex are negative
feedback; stretch reflex is a local reflex stabilizing muscle length.
Keywords: positive feedback, oxytocin, parturition, amplification.
,5. In a physiologic negative-feedback control system, increasing the system gain
(controller responsiveness) generally results in:
A. Greater steady-state error and improved stability.
B. Always more stability and no change in steady-state error.
C. Reduced steady-state error but increased risk of oscillation or instability if gain
is excessive.
D. A shift in the set point of the controlled variable.
Answer: C
Rationale: Gain is the ratio of corrective output to error. High gain improves
tracking (smaller steady-state error) but can lead to overshoot and oscillations
(instability). Clinically, “loop gain” concept explains phenomena such as Cheyne–
Stokes breathing and central sleep apnea — high loop gain predisposes to periodic
breathing. Set point is separate.
Keywords: gain, stability, oscillation, loop gain, Cheyne-Stokes.
6. Which of these best exemplifies feedforward control in human physiology?
A. Cephalic-phase insulin release triggered by sight/smell of food that lowers
postprandial glucose excursions.
B. Renal retention of sodium in response to decreased arterial pressure.
C. Baroreflex responses to an acute hemorrhage.
D. Fever produced by hypothalamic set-point elevation.
Answer: A
Rationale: Feedforward control anticipates a disturbance and acts before the
controlled variable changes. The cephalic insulin response prepares tissues for
incoming glucose, reducing postprandial peaks. Baroreflex and renal retention are
feedback; fever is a set-point change (feedback with altered comparator).
Keywords: feedforward, cephalic phase, anticipatory control, insulin.
7. Fever during infection occurs because pyrogens increase the hypothalamic set
point. The principal adaptive advantage of a moderately elevated body temperature
is:
A. It increases basal metabolic efficiency in stressed tissue.
B. It enhances certain immune functions and reduces replication rates of some
pathogens.
,C. It primarily protects against circulatory collapse.
D. It is solely a maladaptive side effect of infection.
Answer: B
Rationale: Pyrogens (endogenous e.g., IL-1, TNF → PGE₂) raise the
thermoregulatory set point. Moderate fever can enhance leukocyte mobility,
antigen presentation, and impair replication of some microbes. However, extremes
are harmful; antipyretics act via PGE₂ inhibition (e.g., NSAIDs).
Keywords: fever, PGE₂, pyrogens, immune enhancement, set point.
8. An example of redundancy in physiological regulation (multiple mechanisms
serving the same function) is:
A. A single hepatic enzyme that converts all toxic compounds.
B. Erythropoietin being produced exclusively in the liver.
C. Blood pressure regulation via baroreceptor reflex, renin–angiotensin–
aldosterone system (RAAS), and pressure natriuresis by the kidney.
D. Tidal volume controlled only by the medullary respiratory center with no other
inputs.
Answer: C
Rationale: Redundancy means multiple overlapping mechanisms maintain a
critical function (blood pressure). If one mechanism fails or is stressed, others
compensate, conferring robustness. Understanding redundancy explains why
single-target failures often do not immediately produce collapse but chronic stress
can overwhelm multiple systems.
Keywords: redundancy, RAAS, baroreflex, pressure natriuresis, robustness.
9. Regarding acid–base compensation: which statement correctly describes relative
timing of respiratory vs renal compensation?
A. Renal compensation occurs within seconds, while respiratory compensation
takes days.
B. Respiratory compensation is rapid (minutes) and renal compensation is slow
(hours–days).
C. Both renal and respiratory compensations occur within minutes.
D. Neither system has any compensatory capacity; only buffers work.
Answer: B
Rationale: Ventilatory adjustments alter arterial CO₂ within minutes (rapid), while
renal adjustments (H⁺ secretion, HCO₃⁻ reclamation/generation) require hours to
, days to change plasma bicarbonate substantially. Immediate intracellular buffers
act quickly but are limited. Clinical interpretation of ABGs relies on timing.
Keywords: compensation, respiratory (minutes), renal (hours–days), buffers.
10. A patient with autonomic failure stands up and experiences profound
orthostatic hypotension with little compensatory tachycardia. Physiologically, this
occurs because:
A. Venous return increases on standing and the autonomic system overreacts.
B. The heart rate increases excessively due to hypersensitive baroreceptors.
C. Sympathetic efferent responses are impaired so vasoconstriction and heart-rate
increases are inadequate.
D. The kidneys acutely increase sodium excretion causing hypovolemia.
Answer: C
Rationale: On standing blood pools in the legs → decreased venous return →
lower stroke volume. Normally baroreflex increases sympathetic tone
(vasoconstriction, HR) to restore pressure. In autonomic failure the efferent
sympathetic response is blunted, so compensation fails, causing hypotension and
syncope.
Keywords: orthostatic hypotension, autonomic failure, baroreflex efferent.
11. Circadian modulation of homeostatic set points is best explained by which
mechanism?
A. Suprachiasmatic nucleus (SCN) orchestrating daily rhythms through neural and
hormonal outputs (e.g., HPA axis contributing to morning cortisol peak).
B. Circadian rhythms are only a property of peripheral tissues and not centrally
coordinated.
C. Hormones such as cortisol are secreted at steady constant rates and do not
follow circadian patterns.
D. Light and behavioral cues do not entrain physiological rhythms.
Answer: A
Rationale: The SCN acts as the central pacemaker, entrained by light, and
coordinates peripheral clocks and hormonal rhythms (cortisol peaks before
waking). This circadian modulation influences metabolism, temperature, and drug
pharmacodynamics/chronotherapy.
Keywords: circadian, SCN, HPA axis, cortisol peak, entrainment.
