PSIO202 Exam 4 - Urinary Anatomy

Question 1

What are the two primary functions of the kidney?

Answer 1

filter waste from the plasma of the blood, return valuable resources (water and solutes) to the blood

Question 2

How much blood is filtered per minute and per day by the kidneys? How does that relate to normal blood volume?

Answer 2

125 mL per minute
180 L per day
That is 40 times the total blood volume of an adult

Question 3

Kidneys regulate…

Answer 3

ionic composition (Na+, K+, Ca2+, Cl-, phosphate)
blood pH and osmolarity
blood glucose
blood volume (water)
blood pressure (renin or renal resistance)

Question 4

Kidneys release…(2 hormones)

Answer 4

erythropoietin and calcitriol

Question 5

Kidneys excrete…(two things)

Answer 5

wastes and foreign substances

Question 6

What are the 4 major physiological functions of the kidney?

Answer 6

filtration, reabsorption, secretion, and excretion

Question 7

99% of nutrients, electrolytes, etc. filtered from blood plasma…

Answer 7

are returned to the blood through reabsorption

Question 8

What is a renal threshold?

Answer 8

value for all nutrients and electrolytes that will be returned to the blood, and anything above that threshold will be lost in urine

Question 9

About how much water, sodium, bicarbonate, and chloride are excreted each day?

Answer 9

less than 1%

water - 1.5 (out of 180)
sodium - 150 (out of 25,000)
bicarbonate - 2 (out of 4,500)
chloride - 150 (out of 18,000)

Question 10

The kidney has over ——– nephrons, which is (constant/increasing) from birth.

Answer 10

1 million
constant

Question 11

Increased kidney size indicates…

Answer 11

increase size of individual nephrons

Question 12

Can injured kidneys or nephrons be repaired/replaced?

Answer 12

No

Question 13

When does kidney dysfunction become evident? Why?

Answer 13

when it declines to less than 25% of normal

remaining nephrons can handle larger work loads when necessary, and if one kidney is removed the remaining kidney’s nephrons enlarge to handle the additional work)

Question 14

if one kidney is removed, the other kidney can filter –% of the normal rate of two kidneys.

Answer 14

80%

Question 15

The two main parts of a nephron are the…
Their functions are to…

Answer 15

corpuscle (plasma filtration) and tubule (reabsorption)

Question 16

What composes the renal corpuscle? Functions?

Answer 16

glomerulus - knot of capillaries where filtration occurs
glomerular/Bowman’s capsule - double walled epithelial cup that collects filtrate

Question 17

What composes the renal tubule? Basic functions?

Answer 17

proximal convoluted tubule - reabsorption and secretion
loop of Henle - only reabsorption
distal convoluted tubule - reabsorption and secretion

Question 18

How many DCTs drain into one collecting duct?

Answer 18

1 or more

Question 19

What vessels approach and exit the glomerulus?

Answer 19

afferent - approach
efferent - exit

Question 20

What structures do the efferent arterioles immediately lead into?

Answer 20

peritubular capillaries or vasa recta

Question 21

Describe blood flow starting at the renal artery, and ending at the afferent arteriole.

Answer 21

renal artery
segmental arteries
interlobar arteries
arcuate arteries
cortical radiate arteries
afferent arteriole

Question 22

Describe blood flow starting at the efferent arteriole, and ending at the renal vein.

Answer 22

efferent arteriole, peritubular capillaries/vasa recta, cortical radiate veins, arcuate veins, interlobar veins, interlobar veins, renal vein

Question 23

What materials enter the cortical radiate vein, and from what structures?

Answer 23

vasa recta - reabsorbed/secreted
peritubular capillaries - reabsorbed/secreted
efferent arteriole - not filtered

Question 24

The glomerular capsule is always located in the…

Answer 24

cortex

Question 25

The loop of Henle always…

Answer 25

dips down into the medulla

Question 26

What percent of nephrons are cortical vs juxtamedullary?

Answer 26

80-85% cortical
15-20% juxtamedullary

Question 27

Describe the different between cortical and juxtamedullary nephrons.

Answer 27

cortical -
renal corpuscle in outer cortex
loops of Henle in cortex with a dip down into the medulla

juxtamedullary -
corpuscles are in the cortex but close to the medulla
loops of Henle are long and extend deep, almost entirely in the medulla

Question 28

The medulla gets —— as it gets deeper, so a deeper loop of Henle results in more —— reabsorption.

Answer 28

saltier
water reabsorption

Question 29

The kidney receives about –% of the resting cardiac output.

Answer 29

25%

Question 30

What is the difference between the functions of glomerular capillaries and peritubular capillaries/vasa recta?

Answer 30

glomerular - filtration
peritubular capillaries/vasa recta - carry away things reabsorbed from filtrate

Question 31

What regulates the blood flow/renal resistance to the kidney? How?

Answer 31

sympathetic vasomotor nerves alter diameter of arterioles via vasoconstriction and vasodilation

Question 32

Thin epithelium allows for more ——-, so simple squamous is located in the ———- (opposed to the normal simple cuboidal everywhere else)

Answer 32

diffusion

parietal layer of glomerular capsule, descending and thin ascending limbs of the loop of Henle

Question 33

Where are microvilli located? Why?

Answer 33

PCT (proximal con. tubule)
intercalated cells of the collecting duct

more surface area for more reabsorption

Question 34

Where are hormone receptors found, and why?

Answer 34

Distal convoluted tubule cells and principal cells of the collecting duct
regulate BP and filtration rate