L4: GFR cont/ Tubular function

Question 1

What are the 3 cells of the Juxtaglomerular apparatus?

Answer 1

MD -Macula densa
EGM - extraglomerular mesangium
GC - granular cells

Question 2

Info transmitted from ___ cells to the ____ of glomerulus to decrease the GFR by ____

Answer 2

MD, afferent arteriole, increase [Ca]

Question 3

4 summary steps of the TGF

Answer 3

1. Increase in GFR
2. Increase in [NaCl] in tubule fluid in the Loop of Henle
3. MD cells generate a singal
4. Increased resistance of aa (constrict)

Question 4

Draw the TGF figure

Question 5

What is Renal clearance based upon?

Answer 5

Conservation of mass (Fick’s principle)

Question 6

What is renal clearance?

Answer 6

Urinary excretion compared to plasma concentration

Question 7

Clearance of a substance is in referenece to the ____ and can be __,__,__

Answer 7

GFR

> <

Question 8

Renal Clearance Equation

Answer 8

C(s) = [U]s x V /[P]

Question 9

What is the numerator if the renal clearance calculation?

Answer 9

excretion rate of the substance

Question 10

Why is creatinine only estimated GFR?

Answer 10

bc it is secreted 10%

Question 11

When does GFR change? (5)

Answer 11

1. Loss of SA, Kf will decrease
2. Changes in PBS (kidney stones)
3. Altered renal perfusion pressure (PGC)
4. Drugs that dilate/constrict aterioles (can alter Kf)
5. Loss of protein in urine or increased protein synthesis (PiGC)

Question 12

When is FF altered?

Answer 12

Normally remains constant bc of GFR and RBF (autoreg)
Acute/dramatic changes in arterial BP may alter the FF
Decrease BP - diuretics
Increase - Renal artery stenosis

Question 13

Proteinuria

Answer 13

High levels of protein in urine

Question 14

Glomerulus does what

Answer 14

filters plasma

Question 15

Tubule does what

Answer 15

reabsorbs and secretes

Question 16

What is the corpuscle made up of?

Answer 16

Corpuscle = capsule + glomerulus

Question 17

What cells make up the tubule?

Answer 17

Epithelial cell (single layer)

Question 18

The tubule contains different ____ in different segments that are responsible for ____

Answer 18

cell types, diff functions

Question 19

What does the lumen of the tubule contains?

Answer 19

fluid from plasma filtrate

Question 20

Reabsorption is the direction of movement ___

Answer 20

out of the lumen

Question 21

Secretion is the direction of movement____

Answer 21

into the lumen

Question 22

Proximal convoluted tubule (PCT) - is responsible for? The apical surface facing the lumen contains? (for what purpose?) There are numerous transporters for electrolytes on the ________

Answer 22

reabsorption
microvilli - Inc SA
apical cell border

Question 23

Proximal convoluted tubule (PCT)
Reaborsption of ____ of filtered H2O, Na, K, Ca and ___ of HCO3

Answer 23

65%, 80%

Question 24

Proximal convoluted tubule (PCT) reaborbs what to 100%

Answer 24

filtered amino acids - peptides/proteins and glucose

Question 25

Proximal convoluted tubule (PCT) is primarly responsible for?

Answer 25

reabsorption

Question 26

Proximal Nephron is primarily responsible for?

Answer 26

secretion

Question 27

Proximal Straight Tubule (PST)
secretes (3)

Answer 27

1. Foreign substances
2. Substance not metabolized or partially/slow
3. Drug delivery to tubule

Question 28

What is the main purpose of the loop?

Answer 28

to concentrate the urine

Question 29

Loop of Henle
tDLH and tALH
What type of cells?

Answer 29

Cubodial epithelial cells - no active transport

Question 30

Loop of Henle
tDLH and tALH
Allows for osmotic gradient b/w ___ and _____
Passive H2O movement via ____
Passive ____ and ____ movement (channels)

Answer 30

cortex and medulla
aquaporins
Na and urea

Question 31

What is necessary for concentrating capacity of kidney?

Answer 31

Loop of Henle

Question 32

What part of the Loop of Henle is responsible for reabsorption?

Answer 32

TAL - thick ascending limb

Question 33

reabsorbtion of 25% of filtered Na, K and Ca occurs where?

Answer 33

TAL of the Loop of Henle

Question 34

TAL is the site of action of

Answer 34

loop diuretics

Question 35

Loop becomes more _____ going up as more electrolytes are removed and no ___ follows

Answer 35

diluted, water
Absence of water movement (No AQPs)

Question 36

The Distal Nephron is responsible for

Answer 36

reabsorption and secretion

Question 37

What occurs in the DCT and CD? (5)

Answer 37

Na reabsorption
K secretion
Water reabsorption
A/B homeostasis
Final adjustment of lumenal fluid volume and composition