NU110 Exam 4 Actual Exam Style V3 | NU
110 Integrated Human Sciences | Galen
1. Which part of the nephron is primarily responsible for the reabsorption of the majority of
water, glucose, and amino acids?
A. Distal convoluted tubule
B. Proximal convoluted tubule
C. Loop of Henle
D. Collecting duct
Answer: B
Rationale: The proximal convoluted tubule is the site where approximately 65 percent of
the glomerular filtrate is reabsorbed into the blood. It contains specialized microvilli that
significantly increase the surface area available for the transport of solutes. This structure
is essential for recovering vital nutrients before they can be excreted in the urine.
2. Which hormone is secreted by the posterior pituitary to increase water reabsorption in the
collecting ducts?
A. Aldosterone
B. Renin
C. Antidiuretic hormone (ADH)
,D. Atrial natriuretic peptide
Answer: C
Rationale: Antidiuretic hormone, also known as vasopressin, acts directly on the kidneys
to conserve body water. It increases the permeability of the collecting ducts to water,
allowing more water to be returned to the circulatory system. This hormone is crucial for
maintaining fluid balance and regulating the concentration of urine.
3. What is the primary stimulus for the release of renin from the juxtaglomerular apparatus?
A. High levels of circulating sodium
B. An increase in blood glucose levels
C. A decrease in plasma potassium levels
D. A decrease in blood pressure or blood volume
Answer: D
Rationale: Renin is an enzyme released by the kidneys when a drop in blood pressure or
blood volume is detected. It initiates the renin-angiotensin-aldosterone system, which
ultimately leads to vasoconstriction and sodium retention. This physiological response is a
critical homeostatic mechanism to stabilize systemic blood pressure.
4. Glomerular filtration rate (GFR) is defined as the volume of filtrate formed by both kidneys
per:
A. Second
, B. Hour
C. Day
D. Minute
Answer: D
Rationale: Glomerular filtration rate is a standard measure of kidney function that
calculates the amount of blood filtered per minute. In a healthy adult, the average GFR is
approximately 125 milliliters per minute. Monitoring this rate is vital for diagnosing and
managing various stages of chronic kidney disease.
5. The countercurrent multiplier mechanism occurs primarily in which part of the renal
tubule?
A. Proximal tubule
B. Bowman’s capsule
C. Distal tubule
D. Loop of Henle
Answer: D
Rationale: The Loop of Henle utilizes a countercurrent multiplier system to create an
osmotic gradient in the renal medulla. This gradient is necessary for the kidneys to produce
concentrated urine and conserve water. Without this mechanism, the body would lose
excessive amounts of fluid and struggle to maintain electrolyte balance.
110 Integrated Human Sciences | Galen
1. Which part of the nephron is primarily responsible for the reabsorption of the majority of
water, glucose, and amino acids?
A. Distal convoluted tubule
B. Proximal convoluted tubule
C. Loop of Henle
D. Collecting duct
Answer: B
Rationale: The proximal convoluted tubule is the site where approximately 65 percent of
the glomerular filtrate is reabsorbed into the blood. It contains specialized microvilli that
significantly increase the surface area available for the transport of solutes. This structure
is essential for recovering vital nutrients before they can be excreted in the urine.
2. Which hormone is secreted by the posterior pituitary to increase water reabsorption in the
collecting ducts?
A. Aldosterone
B. Renin
C. Antidiuretic hormone (ADH)
,D. Atrial natriuretic peptide
Answer: C
Rationale: Antidiuretic hormone, also known as vasopressin, acts directly on the kidneys
to conserve body water. It increases the permeability of the collecting ducts to water,
allowing more water to be returned to the circulatory system. This hormone is crucial for
maintaining fluid balance and regulating the concentration of urine.
3. What is the primary stimulus for the release of renin from the juxtaglomerular apparatus?
A. High levels of circulating sodium
B. An increase in blood glucose levels
C. A decrease in plasma potassium levels
D. A decrease in blood pressure or blood volume
Answer: D
Rationale: Renin is an enzyme released by the kidneys when a drop in blood pressure or
blood volume is detected. It initiates the renin-angiotensin-aldosterone system, which
ultimately leads to vasoconstriction and sodium retention. This physiological response is a
critical homeostatic mechanism to stabilize systemic blood pressure.
4. Glomerular filtration rate (GFR) is defined as the volume of filtrate formed by both kidneys
per:
A. Second
, B. Hour
C. Day
D. Minute
Answer: D
Rationale: Glomerular filtration rate is a standard measure of kidney function that
calculates the amount of blood filtered per minute. In a healthy adult, the average GFR is
approximately 125 milliliters per minute. Monitoring this rate is vital for diagnosing and
managing various stages of chronic kidney disease.
5. The countercurrent multiplier mechanism occurs primarily in which part of the renal
tubule?
A. Proximal tubule
B. Bowman’s capsule
C. Distal tubule
D. Loop of Henle
Answer: D
Rationale: The Loop of Henle utilizes a countercurrent multiplier system to create an
osmotic gradient in the renal medulla. This gradient is necessary for the kidneys to produce
concentrated urine and conserve water. Without this mechanism, the body would lose
excessive amounts of fluid and struggle to maintain electrolyte balance.
