APHY 102 Exam 1 Questions With Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which organ is primarily responsible for filtering blood and
producing urine?
A. Liver
B. Heart
C. Kidney
D. Spleen
Rationale: The kidneys are the primary organs of the urinary system.
They continuously filter blood, remove metabolic wastes, regulate
electrolyte balance, maintain acid-base homeostasis, and control
blood volume by producing urine. The liver detoxifies substances but
does not produce urine.
2. The functional unit of the kidney is the:
,A. Neuron
B. Alveolus
C. Osteon
D. Nephron
Rationale: The nephron is the microscopic functional unit responsible
for filtration, reabsorption, secretion, and urine formation. Each
kidney contains approximately one million nephrons that work
together to maintain fluid and electrolyte balance.
3. Blood enters the nephron through the:
A. Peritubular capillary
B. Renal vein
C. Afferent arteriole
D. Efferent arteriole
Rationale: The afferent arteriole delivers blood into the glomerulus
where filtration begins. Blood exits through the efferent arteriole after
filtration has occurred.
4. Filtration occurs in the:
,A. Loop of Henle
B. Collecting duct
C. Distal convoluted tubule
D. Glomerulus
Rationale: The glomerulus is a specialized capillary network where
blood pressure forces water and small solutes into Bowman's capsule,
forming the filtrate that will eventually become urine.
5. Which structure surrounds the glomerulus?
A. Renal pelvis
B. Collecting duct
C. Bowman's capsule
D. Loop of Henle
Rationale: Bowman's capsule completely surrounds the glomerulus
and collects the filtrate produced during glomerular filtration before it
enters the proximal convoluted tubule.
6. Which blood vessel carries filtered blood away from the
glomerulus?
, A. Renal artery
B. Afferent arteriole
C. Venule
D. Efferent arteriole
Rationale: After filtration, blood leaves the glomerulus through the
efferent arteriole, which then forms the peritubular capillaries and
vasa recta that participate in reabsorption and secretion.
7. The majority of water and nutrient reabsorption occurs in the:
A. Distal convoluted tubule
B. Collecting duct
C. Loop of Henle
D. Proximal convoluted tubule
Rationale: Approximately 65–70% of filtered water and sodium, as
well as nearly all glucose and amino acids, are reabsorbed in the
proximal convoluted tubule.
8. Which portion of the nephron establishes the osmotic gradient
necessary for concentrating urine?
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which organ is primarily responsible for filtering blood and
producing urine?
A. Liver
B. Heart
C. Kidney
D. Spleen
Rationale: The kidneys are the primary organs of the urinary system.
They continuously filter blood, remove metabolic wastes, regulate
electrolyte balance, maintain acid-base homeostasis, and control
blood volume by producing urine. The liver detoxifies substances but
does not produce urine.
2. The functional unit of the kidney is the:
,A. Neuron
B. Alveolus
C. Osteon
D. Nephron
Rationale: The nephron is the microscopic functional unit responsible
for filtration, reabsorption, secretion, and urine formation. Each
kidney contains approximately one million nephrons that work
together to maintain fluid and electrolyte balance.
3. Blood enters the nephron through the:
A. Peritubular capillary
B. Renal vein
C. Afferent arteriole
D. Efferent arteriole
Rationale: The afferent arteriole delivers blood into the glomerulus
where filtration begins. Blood exits through the efferent arteriole after
filtration has occurred.
4. Filtration occurs in the:
,A. Loop of Henle
B. Collecting duct
C. Distal convoluted tubule
D. Glomerulus
Rationale: The glomerulus is a specialized capillary network where
blood pressure forces water and small solutes into Bowman's capsule,
forming the filtrate that will eventually become urine.
5. Which structure surrounds the glomerulus?
A. Renal pelvis
B. Collecting duct
C. Bowman's capsule
D. Loop of Henle
Rationale: Bowman's capsule completely surrounds the glomerulus
and collects the filtrate produced during glomerular filtration before it
enters the proximal convoluted tubule.
6. Which blood vessel carries filtered blood away from the
glomerulus?
, A. Renal artery
B. Afferent arteriole
C. Venule
D. Efferent arteriole
Rationale: After filtration, blood leaves the glomerulus through the
efferent arteriole, which then forms the peritubular capillaries and
vasa recta that participate in reabsorption and secretion.
7. The majority of water and nutrient reabsorption occurs in the:
A. Distal convoluted tubule
B. Collecting duct
C. Loop of Henle
D. Proximal convoluted tubule
Rationale: Approximately 65–70% of filtered water and sodium, as
well as nearly all glucose and amino acids, are reabsorbed in the
proximal convoluted tubule.
8. Which portion of the nephron establishes the osmotic gradient
necessary for concentrating urine?
