Chamberlain University BIOS-256 Anatomy &
Physiology IV with Lab – Comprehensive Study
Guide, Original Practice Questions & Answers, BIOS
256 Exam Preparation, A&P IV Review, Digestive
System, Nutrition & Metabolism, Urinary System,
Fluid & Electrolyte Balance, Acid-Base Balance,
Reproductive System, Endocrine Regulation,
Homeostasis & Laboratory Practicum Preparation
Question 1: Which of the following best describes the primary function of the
respiratory membrane in the context of gas exchange?
A. To transport oxygen bound to hemoglobin
B. To facilitate diffusion of gases between alveolar air and pulmonary capillary blood
C. To regulate the pH of the blood by controlling carbonic acid levels
D. To humidify and warm inspired air
CORRECT ANSWER: B. To facilitate diffusion of gases between alveolar air and
pulmonary capillary blood
Rationale: The respiratory membrane, composed of the alveolar epithelium, capillary
endothelium, and their fused basement membranes, provides a thin barrier that allows
for efficient diffusion of oxygen into the blood and carbon dioxide out of the blood.
Options A, C, and D describe other processes (transport, pH regulation, and
conditioning of air) that are not the primary function of this membrane.
Question 2: In renal physiology, what is the primary driving force for
glomerular filtration?
A. Osmotic pressure of plasma proteins
B. Hydrostatic pressure of blood in the glomerular capillaries
C. Active transport of sodium across the glomerular membrane
D. Capsular hydrostatic pressure within Bowman's space
CORRECT ANSWER: B. Hydrostatic pressure of blood in the glomerular
capillaries
Rationale: Glomerular filtration is a passive process driven primarily by the hydrostatic
pressure of blood in the glomerular capillaries, which forces fluid and solutes through
the filtration membrane. Osmotic pressure and capsular pressure oppose this, and
filtration does not involve active transport.
Question 3: Which of the following hormones directly increases water
reabsorption in the collecting ducts of the kidney?
,A. Aldosterone
B. Atrial natriuretic peptide
C. Antidiuretic hormone (ADH)
D. Parathyroid hormone
CORRECT ANSWER: C. Antidiuretic hormone (ADH)
Rationale: ADH acts on the collecting ducts to insert aquaporin-2 channels into the
apical membrane, increasing water permeability and reabsorption. Aldosterone
increases sodium reabsorption, ANP decreases it, and PTH primarily regulates calcium.
Question 4: Which arterial blood gas parameter is most directly affected by
changes in alveolar ventilation?
A. PaCO₂
B. PaO₂
C. HCO₃⁻
D. pH
CORRECT ANSWER: A. PaCO₂
Rationale: PaCO₂ is inversely proportional to alveolar ventilation; increased ventilation
reduces PaCO₂, and decreased ventilation raises it. PaO₂ is also affected but less directly,
and HCO₃⁻ is regulated metabolically.
Question 5: What is the normal resting value for the glomerular filtration rate
(GFR) in a healthy adult?
A. 25 mL/min
B. 80 mL/min
C. 125 mL/min
D. 250 mL/min
CORRECT ANSWER: C. 125 mL/min
Rationale: In a healthy adult, the normal GFR is approximately 125 mL/min, indicating
the volume of plasma filtered by the kidneys per minute. This value reflects efficient
kidney function.
Question 6: Which of the following best describes the role of the
juxtaglomerular apparatus in renal autoregulation?
A. It secretes renin in response to decreased blood pressure
B. It directly reabsorbs glucose from the filtrate
C. It produces ADH to increase water reabsorption
D. It regulates the concentration of urea in the medulla
,CORRECT ANSWER: A. It secretes renin in response to decreased blood
pressure
Rationale: The juxtaglomerular apparatus, comprising macula densa and granular cells,
secretes renin when renal blood pressure drops. This activates the renin-angiotensin-
aldosterone system to increase blood pressure and GFR.
Question 7: Which of the following is an essential component of the intrinsic
pathway of blood coagulation?
A. Tissue factor
B. Factor XII (Hageman factor)
C. Factor VII
D. Calcium ions only
CORRECT ANSWER: B. Factor XII (Hageman factor)
Rationale: The intrinsic pathway is initiated by Factor XII when it contacts negatively
charged surfaces, such as exposed collagen. Tissue factor and Factor VII are
components of the extrinsic pathway.
Question 8: In acid-base balance, which organ system is the primary
compensator for metabolic acidosis?
A. The kidneys
B. The lungs
C. The liver
D. The pancreas
CORRECT ANSWER: B. The lungs
Rationale: In metabolic acidosis, the lungs compensate by increasing ventilation to blow
off carbon dioxide, lowering PaCO₂. The kidneys are the primary regulators of
bicarbonate but respond more slowly.
Question 9: Which of the following statements about the countercurrent
multiplier system in the kidney is correct?
A. It establishes a concentration gradient in the renal medulla
B. It occurs primarily in the proximal convoluted tubule
C. It dilutes the urine to below plasma osmolarity
D. It depends on passive transport of sodium and chloride
CORRECT ANSWER: A. It establishes a concentration gradient in the renal
medulla
, Rationale: The countercurrent multiplier system, located in the loop of Henle, creates a
high osmotic gradient in the medulla by active transport of Na⁺ and Cl⁻, enabling the
kidney to concentrate urine.
Question 10: Which of the following conditions would most likely cause an
increased anion gap metabolic acidosis?
A. Diarrhea
B. Renal tubular acidosis
C. Diabetic ketoacidosis
D. Chronic obstructive pulmonary disease
CORRECT ANSWER: C. Diabetic ketoacidosis
Rationale: Diabetic ketoacidosis produces ketoacids, increasing the anion gap due to
unmeasured anions. Diarrhea and renal tubular acidosis cause normal anion gap
acidosis, and COPD typically causes respiratory acidosis.
Question 11: What is the role of erythropoietin in the body?
A. To stimulate platelet production
B. To enhance the production of red blood cells in the bone marrow
C. To increase the affinity of hemoglobin for oxygen
D. To break down fibrin clots
CORRECT ANSWER: B. To enhance the production of red blood cells in the
bone marrow
Rationale: Erythropoietin, produced primarily by the kidneys in response to hypoxia,
stimulates erythropoiesis in the bone marrow, increasing the red blood cell mass and
oxygen-carrying capacity.
Question 12: Which of the following is the correct order of blood flow through
the nephron?
A. Glomerulus → Proximal convoluted tubule → Loop of Henle → Distal convoluted
tubule → Collecting duct
B. Glomerulus → Loop of Henle → Proximal convoluted tubule → Distal convoluted
tubule → Collecting duct
C. Proximal convoluted tubule → Glomerulus → Loop of Henle → Collecting duct →
Distal convoluted tubule
D. Collecting duct → Proximal convoluted tubule → Loop of Henle → Distal convoluted
tubule → Glomerulus
Physiology IV with Lab – Comprehensive Study
Guide, Original Practice Questions & Answers, BIOS
256 Exam Preparation, A&P IV Review, Digestive
System, Nutrition & Metabolism, Urinary System,
Fluid & Electrolyte Balance, Acid-Base Balance,
Reproductive System, Endocrine Regulation,
Homeostasis & Laboratory Practicum Preparation
Question 1: Which of the following best describes the primary function of the
respiratory membrane in the context of gas exchange?
A. To transport oxygen bound to hemoglobin
B. To facilitate diffusion of gases between alveolar air and pulmonary capillary blood
C. To regulate the pH of the blood by controlling carbonic acid levels
D. To humidify and warm inspired air
CORRECT ANSWER: B. To facilitate diffusion of gases between alveolar air and
pulmonary capillary blood
Rationale: The respiratory membrane, composed of the alveolar epithelium, capillary
endothelium, and their fused basement membranes, provides a thin barrier that allows
for efficient diffusion of oxygen into the blood and carbon dioxide out of the blood.
Options A, C, and D describe other processes (transport, pH regulation, and
conditioning of air) that are not the primary function of this membrane.
Question 2: In renal physiology, what is the primary driving force for
glomerular filtration?
A. Osmotic pressure of plasma proteins
B. Hydrostatic pressure of blood in the glomerular capillaries
C. Active transport of sodium across the glomerular membrane
D. Capsular hydrostatic pressure within Bowman's space
CORRECT ANSWER: B. Hydrostatic pressure of blood in the glomerular
capillaries
Rationale: Glomerular filtration is a passive process driven primarily by the hydrostatic
pressure of blood in the glomerular capillaries, which forces fluid and solutes through
the filtration membrane. Osmotic pressure and capsular pressure oppose this, and
filtration does not involve active transport.
Question 3: Which of the following hormones directly increases water
reabsorption in the collecting ducts of the kidney?
,A. Aldosterone
B. Atrial natriuretic peptide
C. Antidiuretic hormone (ADH)
D. Parathyroid hormone
CORRECT ANSWER: C. Antidiuretic hormone (ADH)
Rationale: ADH acts on the collecting ducts to insert aquaporin-2 channels into the
apical membrane, increasing water permeability and reabsorption. Aldosterone
increases sodium reabsorption, ANP decreases it, and PTH primarily regulates calcium.
Question 4: Which arterial blood gas parameter is most directly affected by
changes in alveolar ventilation?
A. PaCO₂
B. PaO₂
C. HCO₃⁻
D. pH
CORRECT ANSWER: A. PaCO₂
Rationale: PaCO₂ is inversely proportional to alveolar ventilation; increased ventilation
reduces PaCO₂, and decreased ventilation raises it. PaO₂ is also affected but less directly,
and HCO₃⁻ is regulated metabolically.
Question 5: What is the normal resting value for the glomerular filtration rate
(GFR) in a healthy adult?
A. 25 mL/min
B. 80 mL/min
C. 125 mL/min
D. 250 mL/min
CORRECT ANSWER: C. 125 mL/min
Rationale: In a healthy adult, the normal GFR is approximately 125 mL/min, indicating
the volume of plasma filtered by the kidneys per minute. This value reflects efficient
kidney function.
Question 6: Which of the following best describes the role of the
juxtaglomerular apparatus in renal autoregulation?
A. It secretes renin in response to decreased blood pressure
B. It directly reabsorbs glucose from the filtrate
C. It produces ADH to increase water reabsorption
D. It regulates the concentration of urea in the medulla
,CORRECT ANSWER: A. It secretes renin in response to decreased blood
pressure
Rationale: The juxtaglomerular apparatus, comprising macula densa and granular cells,
secretes renin when renal blood pressure drops. This activates the renin-angiotensin-
aldosterone system to increase blood pressure and GFR.
Question 7: Which of the following is an essential component of the intrinsic
pathway of blood coagulation?
A. Tissue factor
B. Factor XII (Hageman factor)
C. Factor VII
D. Calcium ions only
CORRECT ANSWER: B. Factor XII (Hageman factor)
Rationale: The intrinsic pathway is initiated by Factor XII when it contacts negatively
charged surfaces, such as exposed collagen. Tissue factor and Factor VII are
components of the extrinsic pathway.
Question 8: In acid-base balance, which organ system is the primary
compensator for metabolic acidosis?
A. The kidneys
B. The lungs
C. The liver
D. The pancreas
CORRECT ANSWER: B. The lungs
Rationale: In metabolic acidosis, the lungs compensate by increasing ventilation to blow
off carbon dioxide, lowering PaCO₂. The kidneys are the primary regulators of
bicarbonate but respond more slowly.
Question 9: Which of the following statements about the countercurrent
multiplier system in the kidney is correct?
A. It establishes a concentration gradient in the renal medulla
B. It occurs primarily in the proximal convoluted tubule
C. It dilutes the urine to below plasma osmolarity
D. It depends on passive transport of sodium and chloride
CORRECT ANSWER: A. It establishes a concentration gradient in the renal
medulla
, Rationale: The countercurrent multiplier system, located in the loop of Henle, creates a
high osmotic gradient in the medulla by active transport of Na⁺ and Cl⁻, enabling the
kidney to concentrate urine.
Question 10: Which of the following conditions would most likely cause an
increased anion gap metabolic acidosis?
A. Diarrhea
B. Renal tubular acidosis
C. Diabetic ketoacidosis
D. Chronic obstructive pulmonary disease
CORRECT ANSWER: C. Diabetic ketoacidosis
Rationale: Diabetic ketoacidosis produces ketoacids, increasing the anion gap due to
unmeasured anions. Diarrhea and renal tubular acidosis cause normal anion gap
acidosis, and COPD typically causes respiratory acidosis.
Question 11: What is the role of erythropoietin in the body?
A. To stimulate platelet production
B. To enhance the production of red blood cells in the bone marrow
C. To increase the affinity of hemoglobin for oxygen
D. To break down fibrin clots
CORRECT ANSWER: B. To enhance the production of red blood cells in the
bone marrow
Rationale: Erythropoietin, produced primarily by the kidneys in response to hypoxia,
stimulates erythropoiesis in the bone marrow, increasing the red blood cell mass and
oxygen-carrying capacity.
Question 12: Which of the following is the correct order of blood flow through
the nephron?
A. Glomerulus → Proximal convoluted tubule → Loop of Henle → Distal convoluted
tubule → Collecting duct
B. Glomerulus → Loop of Henle → Proximal convoluted tubule → Distal convoluted
tubule → Collecting duct
C. Proximal convoluted tubule → Glomerulus → Loop of Henle → Collecting duct →
Distal convoluted tubule
D. Collecting duct → Proximal convoluted tubule → Loop of Henle → Distal convoluted
tubule → Glomerulus
