Urinary System

Question 1

What are the functions of the urinary system & kidneys? (6)

Answer 1

filters the blood, removes waste, regulates blood volume, produces renin and EPO, metabolizes vitamin D, and maintain salt and pH balance

Question 2

Which kidney sits lower?

Answer 2

the right one

Question 3

Where is the juxtaglomerular apparatus located?

Answer 3

distal part of the ascending limb against the afferent arteriole

Question 4

What three things does the juxtaglomerular apparatus regulate?

Answer 4

GFR (rate at which plasma is filtered), BP, sodium & chloride

Question 5

Where is the filtration membrane located?

Answer 5

between blood & interior of glomerular capsule

Question 6

What are the three layers of the filtration membrane?

Answer 6

capillary endothelium, podocytes, and a shared basement membrane (between the two)

Question 7

What does the filtration membrane do?

Answer 7

allows passage of water and solutes smaller than plasma proteins

Question 8

What are the 3 processes of urine formation?

Answer 8

glomerular filtration, tubular absorption, and tubular secretion

Question 9

What is glomerular filtration?

Answer 9

forming filtrate (pre-urine) - movement from glomerular capillary into capsule space

Question 10

What is tubular absorption?

Answer 10

reabsorbing back water and nutrients - movement from renal tubules into peritubular capillary bed

Question 11

What is tubular secretion?

Answer 11

removing waste from blood stream - movement of substances into renal tubules

Question 12

What is net filtration pressure?

Answer 12

10 mm Hg

Question 13

What force is in FAVOR of making filtrate?

Answer 13

glomerular hydrostatic pressure (BP) - 55 mm Hg

Question 14

What forces are AGAINST making filtrate? (2)

Answer 14

• blood osmotic pressure - 30 mm Hg

- capsular hydrostatic pressure - 15mm Hg

Question 15

Where are all substances your body wants back reabsorbed the most?

Answer 15

proximal convoluted tubule

Question 16

What % of water is reabsorbed by the proximal convoluted tubule?

Answer 16

65%

Question 17

What % of water is reabsorbed via the descending loop?

Answer 17

15%

Question 18

What is the countercurrent multiplier?

Answer 18

• descending loop is permeable to water but not Na & Cl
• ascending loop is permeable to Na & Cl but not water
• this creates an osmotic gradient

Question 19

What hormone is the distal convoluted tubule sensitive to?

Answer 19

ADH

Question 20

When will you produce ADH and what happens?

Answer 20

• ADH is produced when you’re dehydrated

- ADH causes aquaporins to open in the DCT, causing the reabsorption of water

Question 21

What substances are removed during tubular secretion?

Answer 21

metabolic waste, excess ions (H+ ions), metabolized drugs

Question 22

What is the pH of urine?

Answer 22

6, slightly acidic

Question 23

What is a normal urine volume per day?

Answer 23

1-2 liters

Question 24

Urine should not contain what? (7)

Answer 24

RBC, glucose, plasma proteins, ketones, bile pigments, proteins, leukocytes (pus)

Question 25

Where do kidney stones form?

Answer 25

loop of henle

Question 26

What 3 layers make up the ureter?

Answer 26

inner - mucus membrane
middle - muscularis
outer - adventitia

Question 27

How long is the female urethra?

Answer 27

1.5 inches long

Question 28

How long is the male urethra?

Answer 28

penile varies, prostatic urethra is 1 inch, intermediate is

Question 29

What muscle causes the urinary bladder to contract and at how many mL of urine does it contract?

Answer 29

detruser muscle, 300 mL

Question 30

How much urine can your bladder hold?

Answer 30

up to 500mL or 1 pint

Question 31

What are the internal and external urethral sphincters made of?

Answer 31

internal - smooth muscle

external - skeletal muscle