Renal Anatomy
What is the correct order of the encapsulating layers of the kidney from outside to inside?
A. Renal capsule, perirenal fat, perirenal fascia, pararenal fat
B. Pararenal fat, perirenal fascia, perirenal fat, renal capsule
C. Pararenal fat, perirenal fat, perirenal fascia, renal capsule
D. Perirenal fascia, pararenal fat, renal capsule, perirenal fat
E. Pararenal fat, renal capsule, perirenal fat, perirenal fascia
B. Pararenal fat, perirenal fascia, perirenal fat, renal capsule
Which two components make up the renal corpuscle in the nephron?
Glomerulus and Bowman capsule
In the RAAS, which of the following is a trigger of the secretion of renin?
A. Low serum potassium concentration
B. High systemic arterial blood pressure
C. Stimulation of β1 receptors in the kidneys
D. Release of angiotensin II
E. Production of aldosterone
C. Stimulation of β1 receptors in the kidneys
Which of the following conditions may result from excessive aldosterone levels?
A. Hyponatremia
B. Hyperkalemia
C. Metabolic acidosis
D. Hypovolemia
E. None of the above
E. None of the above
Excessive aldosterone secretion would tend to result in hypernatremia, hypokalemia, metabolic alkalosis, hypervolemia, as well as hypertension.
Which of the following is a direct effect of ANP on the kidneys?
A. Increased renin secretion
B. Decreased excretion of NaCl
C. Increased excretion of NaCl and water
D. Increased sodium reabsorption in the collecting ducts
E. Vasoconstriction of renal blood vessels
C. Increased excretion of NaCl and water
Which structures are found in the renal cortex?
A. Loops of Henle and collecting ducts
B. Minor and major calyces
C. Glomeruli, proximal convoluted tubules, distal convoluted tubules, and cortical collecting ducts
D. Renal pyramids and renal papillae
E. Vasa recta and arcuate arteries
C. Glomeruli, proximal convoluted tubules, distal convoluted tubules, and cortical collecting ducts
Which process occurs in the renal corpuscle?
A. Active transport of glucose into the tubules
B. Passive filtration of plasma
C. Secretion of renin
D. Reabsorption of water
E. Production of erythropoietin
B. Passive filtration of plasma
What effect does aldosterone have in the RAAS?
A. Causes vasodilation
B. Promotes water excretion
C. Inhibits sodium reabsorption
D. Stimulates potassium secretion
E. Decreases blood pressure
D. Stimulates potassium secretion
In which condition is aldosterone secretion most likely to be decreased?
A. Conn syndrome
B. Renovascular hypertension
C. Addison's disease
D. Hyperthyroidism
E. Cushing's syndrome
C. Addison's disease
- In Conn syndrome, there is typically an autonomous production of aldosterone due to a tumor in the adrenal gland. This results in increased aldosterone secretion rather than decreased secretion.
- Renovascular hypertension can lead to increased aldosterone secretion due to decreased renal perfusion, which activates the renin-angiotensin-aldosterone system (RAAS).
- Hyperthyroidism typically does not directly affect aldosterone secretion.
- Cushing's syndrome is associated with excess cortisol production, which can suppress the secretion of aldosterone.
Two questions (must correctly answer both Q's for credit):
1) What is the primary trigger for the release of ADH from the posterior pituitary?
2) In the absence of ADH, which of the following occurs?
A. Increased water reabsorption in the collecting duct
B. Decreased urine output
C. Increased urine osmolarity
D. Decreased plasma osmolarity
E. Increased urine output
1) Increased plasma osmolarity
2) E. Increased urine output
Which statement is true regarding the renal medulla?
A. It contains the glomeruli and Bowman's capsules
B. It is more vulnerable to hypoxia due to relatively low blood flow
C. It has higher blood flow compared to the renal cortex
D. It extends inward as renal columns dividing the cortex
E. It is enveloped by the perirenal fascia
B. It is more vulnerable to hypoxia due to relatively low blood flow
What is the glomerular filtration rate (GFR) a measure of?
A. The total amount of urine produced per day
B. The volume of primary ultrafiltrate filtered into the Bowman capsule per unit of time
C. The amount of blood flowing through the kidneys per minute
D. The concentration of electrolytes in the urine
E. The reabsorption rate of glucose in the proximal tubule
B. The volume of primary ultrafiltrate filtered into the Bowman capsule per unit of time
Which hormone is responsible for negative feedback regulation of the RAAS?
A. Renin
B. Angiotensin II
C. Aldosterone
D. Atrial natriuretic peptide (ANP)
E. Dopamine
D. Atrial natriuretic peptide (ANP)
Negative feedback:
↑ systemic arterial blood pressure
→ ANP release from atrial myocytes
→ inhibition of renin release
→ vasodilation, natriuresis, and ↑ diuresis
Which of the following describes the function of aldosterone in the kidney?
A. Inhibiting sodium reabsorption
B. Stimulating potassium retention
C. Promoting water excretion
D. Inhibiting hydrogen ion secretion
E. Enhancing chloride reabsorption
E. Enhancing chloride reabsorption
Explanation: Aldosterone promotes sodium reabsorption, which indirectly leads to chloride reabsorption.
Aldosterone increases the expression of apical hydrogen ATPases to stimulate hydrogen ion excretion into the lumen. This helps to maintain acid-base balance.
Define pressure natriuresis.
Pressure natriuresis (PN) is the process by which the kidneys increase sodium excretion and decrease extracellular fluid when renal perfusion pressure increases. This process helps maintain normal sodium balance and systemic arterial pressure.
The renal hilum is the entry and exit point for which structures?
A. Renal arteries and veins and renal pelvis
B. Ureters, blood vessels, lymph vessels, and nerves
C. Adrenal gland, perirenal fascia, and pararenal fat
D. Minor calyces, major calyces, and renal pyramids
E. Glomeruli, loops of Henle, and cortical collecting ducts
B. Renal pelvis, vessels, and nerves
How do NSAIDs affect renal function?
Decrease prostaglandin synthesis, leading to reduced renal blood flow
(Prostaglandins dilate the afferent arteriole)
Which component of the renin-angiotensin-aldosterone system (RAAS) is likely to be affected in primary adrenal insufficiency?
A. Renin
B. Angiotensin-converting enzyme (ACE)
C. Aldosterone
D. Angiotensin II
E. Atrial natriuretic peptide (ANP)
Answer: C. Aldosterone
What are the primary sites of aldosterone action within the nephron? (2 sites)
Distal convoluted tubule and collecting duct
ADH primarily acts on which part of the nephron to regulate water reabsorption?
Collecting duct
Which of the following correctly describes the relationship of the left renal vein to the aorta and superior mesenteric artery? (You may answer by describing OR drawing the relationship.)
The left renal vein crosses between the aorta and SMA.
(The left renal vein is anterior to the aorta and posterior to the SMA.)
What is the role of countercurrent multiplication in the kidney?
A. It converts calcidiol to calcitriol in the proximal convoluted tubule
B. It allows for passive water reabsorption due to a hypertonic interstitium
C. It stimulates erythropoiesis in response to hypoxia
D. It regulates the secretion of renin in response to blood pressure changes
E. It increases sodium excretion in the proximal convoluted tubule
B. It allows for passive water reabsorption due to a hypertonic interstitium
Name four drug classes that target the RAAS.
1. Direct renin inhibitors
2. Angiotensin-converting enzyme (ACE) inhibitors
3. Angiotensin II receptor blockers (ARBs)
4. Aldosterone antagonists (aldosterone receptor blockers)
Name two medications which directly block aldosterone receptors in the kidney.
Spironolactone & Eplerenone
These drugs are known as mineralocorticoid receptor antagonists (MRAs) and are used to counteract the effects of aldosterone in conditions such as heart failure and hypertension.
Two questions (must correctly answer both Q's for credit):
1) Define effective circulating volume
2) Which of the following play a role in regulating effective circulating volume? (select all that apply)
A. RAAS
B. ANP
C. ADH
D. Insulin
E. Thirst mechanism
1) Def. of effective circulating volume - The portion of extracellular fluid in the arterial system that effectively perfuses tissue.
2) Regulators of effective circulating volume: All except insulin