Kidney

Question 1

Q: What are the three major regions of the kidney?

Answer 1

A: Cortex/ medulla/ renal pelvis.

Question 2

Q: What structures are found in the renal cortex?

Answer 2

A: Glomeruli and convoluted tubules.

Question 3

Q: What structures are found in the renal medulla?

Answer 3

A: Loops of Henle and collecting ducts.

Question 4

Q: Trace the renal blood pathway.

Answer 4

A: Renal artery → afferent arteriole → glomerulus → efferent arteriole → peritubular capillaries → renal vein.

Question 5

Q: What percentage of nephrons are cortical nephrons?

Answer 5

A: 85%.

Question 6

Q: What is the function of cortical nephrons?

Answer 6

A: Bulk reabsorption; short loops.

Question 7

Q: What is the function of juxtamedullary nephrons?

Answer 7

A: Long loops that create osmotic gradient for concentrated urine.

Question 8

Q: List the main segments of the nephron.

Answer 8

A: Glomerular capsule / PCT / loop of Henle / DCT / collecting duct.

Question 9

Q: What is filtration?

Answer 9

A: Blood → tubule (glomerulus to Bowman’s capsule).

Question 10

Q: What is reabsorption?

Answer 10

A: Moving useful solutes (nutrients/ ions) and water out of the tubules and back into the blood.

Question 11

Q: What is secretion?

Answer 11

A: Moving substances from the Blood to the tubules (toxins / drugs / ions).

Question 12

Q: What is excretion?

Answer 12

A: Removal of urine from the body.

Question 13

Q: What structures create the filtration membrane?

Answer 13

A: Fenestrated capillaries / basement membrane / podocyte slits.

Question 14

Q: What is the normal Glomerular Filtration Rate (GFR)?

Answer 14

A: ~125 mL/min (~180 L/day).

Question 15

Q: What is the effect of the basement membrane’s negative charge?

Answer 15

A: Helps keep proteins in the blood.

Question 16

Q: What pressures determine glomerular filtration?

Answer 16

A: Hydrostatic pressure / osmotic pressure / capsular pressure.

Question 17

Q: What are intrinsic controls of GFR?

Answer 17

A: Myogenic mechanism & tubuloglomerular feedback.

Question 18

Q: What are extrinsic controls of GFR?

Answer 18

A: Heart rate & blood pressure regulation.

Question 19

Q: How much Na⁺ and water does the PCT reabsorb?

Answer 19

A: ~65%.

Question 20

Q: What else is reabsorbed in the PCT?

Answer 20

A: Glucose and amino acids.

Question 21

Q: What does the descending limb reabsorb?

Answer 21

A: Water only.

Question 22

Q: What does the ascending limb reabsorb?

Answer 22

A: Na⁺/ K⁺/ Cl⁻ (impermeable to water).

Question 23

Q: What hormones act on the DCT?

Answer 23

A: Aldosterone and ADH.

Question 24

Q: What does aldosterone do in the kidney?

Answer 24

A: Increases Na⁺ & water reabsorption; K⁺ secretion

Question 25

Q: What does ADH do in the nephron?

Answer 25

A: Inserts aquaporin-2 → increases water reabsorption.

Question 26

Q: What substances are secreted in the PCT?

Answer 26

A: H⁺/ K⁺/ drugs/ organic anions.

Question 27

Q: What is secreted in the DCT?

Answer 27

A: K⁺.

Question 28

Q: What does Atrial Natriuretic Peptide (ANP) do?

Answer 28

A: Inhibits Na⁺ reabsorption → increases urine output.

Question 29

Q: What does the renin-angiotensin system regulate?

Answer 29

A: Blood pressure and GFR.

Question 30

Q: How do sympathetic nerves affect urine formation?

Answer 30

A: Increase HR/BP → increase filtration → more urine

Question 31

Q: How does the myogenic mechanism respond to ↑ BP?

Answer 31

A: Afferent arteriole constricts → lowers GFR.

Question 32

Q: How does the macula densa respond to high NaCl?

Answer 32

A: Releases adenosine → afferent constriction → ↓ GFR.

Question 33

Q: How does the macula densa respond to low NaCl?

Answer 33

A: Releases prostaglandins → renin release → efferent constriction → restores GFR.

Question 34

Q: What labs assess kidney function?

Answer 34

A: GFR / creatinine clearance / BUN.