Ch. 35: Structure and Function of the Renal and Urologic Systems

Question 1

Which of the following is NOT one of the three kinds of nephrons?
  Superficial cortical nephrons
  Midcortical nephrons
  Juxtamedullary nephrons
  Glomerular nephrons

Answer 1

Glomerular nephrons

Nephrons are the functional units of the kidney. The three types include superficial, midcortical, and juxtamedullary.

Question 2

In the distal tubule, which cells reabsorb sodium and water but secrete potassium?
  Distal cells
  Proximal cells
  Principal cells
  Intercalated cells

Answer 2

Principal cells

Principal cells reabsorb sodium and water and secrete potassium. Intercalated cells secrete either hydrogen or bicarbonate and reabsorb potassium. Distal and proximal refer to the tubules.

Question 3

Which muscle lies between the two openings of the ureter and urethra?
  Micturition
  Detrusor
  Trigone
  Urethra

Answer 3

Trigone

The trigone is a smooth triangular area in the bladder that lies between the openings of the two ureters and the urethra. The detrusor muscle distends as the bladder fills with urine and is composed of smooth muscle fibers that weave around the bladder bag. Micturition is another term for urination. Urethra is the term for the tube that connects the bladder to the outside of the body.

Question 4

Which of the following is TRUE regarding renal blood flow?
The kidneys are highly vascular organs and receive 1000 to 1200 ml of blood per minute.
The kidneys receive 50% of cardiac output.
The GFR is not related to renal blood flow.
No autoregulation is found in renal blood flow.

Answer 4

The kidneys are highly vascular organs and receive 1000 to 1200 ml of blood per minute.

The kidneys are vascular organs and receive 1000 to 1200 ml of blood per minute and 20% to 25% of cardiac output. The GFR is related to renal blood flow, and autoregulation is found in renal blood flow.

Question 5

A person experiences hypotension. Which of the following enzymes is primarily released?
  Renin
  Angiotensin I
  Angiotensin II
  Angiotensin III

Answer 5

Renin

Primarily, renin is released, which starts a cascade of events that leads to the angiotensins.

Question 6

What is the appropriate term for when fluid moves from the tubular lumen to the peritubular capillary plasma?
  Ultrafiltration
  Tubular reabsorption
  Tubular secretion
  Excretion

Answer 6

Tubular reabsorption

Tubular reabsorption is the movement of fluids and solute from the tubular lumen to the peritubular capillary plasma. Ultrafiltration is the process of filtration across the glomerular capillaries to form a filtrate of protein-free plasma. Tubular secretion refers to substances moving from the plasma of the capillary to the tubular lumen. Excretion is the elimination of the substance in the final urine.

Question 7

Which substance controls final urine concentration?
  Antidiuretic hormone
  Renin
  Angiotensin I
  Urea

Answer 7

Antidiuretic hormone

Antidiuretic hormone is secreted from the posterior pituitary; it increases water permeability in the last segment of the distal tubule. Renin stimulates the renin-angiotensin-aldosterone system, which can increase systemic arterial pressure and change renal blood flow. Renin forms angiotensin I that is converted to angiotensin II, which stimulates the secretion of aldosterone.

Question 8

Which of the following is a correct finding in a normal urinalysis?
  pH <5
  Dark yellow urine
  Specific gravity 1.016 to 1.022 
  Two to five red blood cells

Answer 8

Specific gravity 1.016 to 1.022

The pH is generally 5 to 6.5, the urine is light yellow, the specific gravity is 1.016 to 1.022, and there are no white or red blood cells.