L6: Tubular Function 3

Question 1

What is the filtered load?

Answer 1

How much is coming into the tubule

Question 2

Filtered load “s” =

Answer 2

Filtered load “s” = GFR x plasma concentration (Ps)

Question 3

Excretion rate =

Answer 3

Excretion rate = V x urinary concentration (of a specific solute)

Question 4

Fractional excretion (FE) =

Answer 4

FEs = excretion rate of s/ filtered load of s

Question 5

The PST secretes __

Answer 5

organic anions (OA)/ organic cations (OC)

Question 6

The PCT, TAL, IC secretes___

Answer 6

NH4,H,HCO3

Question 7

CD principal cells secrete __

Answer 7

K (aldosterone)

Question 8

What is the site of secretion of organic compunds?

Answer 8

PST

Question 9

OAT

Answer 9

Organic anion transporters

Question 10

Some OATs are depend on

Answer 10

dependant

Question 11

How can we transport many OA?

Answer 11

The OATs have low specificity so transport of many

Question 12

The secrtion of OA is linked to ___

Answer 12

alpha-KG

Question 13

What do OAs compete for?

Answer 13

secretory pathways

Question 14

What is the ATP dependent pathway in OC secretion?

Answer 14

MDR1

Question 15

For cations we only need ___ type of transporter

Answer 15

1

Question 16

MATE

Answer 16

multi drug and toxin exchanger

Question 17

Where is the OCT2?

Answer 17

on the basolateral membrane

Question 18

Where is the rate limiting step ____? why?

Answer 18

on the apical membrane because MDR1 is ATP-dependant

Question 19

Is organic cation transport specific?

Answer 19

no it is non-specific or polyspecific (can pretty much carry any organic cations)

Question 20

Give two examples of endo and exo OC and OA secreted by PST

Answer 20

OA
endo - creatinine, Bile salts
exo - Penicilin G, PAH

OC
endo- Dopamine, histamine
exo- Morphine, NMN

Question 21

Aldosterone promotes ___ secretion in ____ _____

Answer 21

K+, prinicipal cells

Question 22

Aldosterone is a steroid so it can move thorugh cells

Answer 22

passively through diffusion

Question 23

4 steps of aldosterone PE

Answer 23

1. Diffuses into cell (CollectingD)
2. Binds to Mineralcorticoid recpetor)
3. Synthesis of mRNA for ENaC (epithelial sodium channel) and Na/K ATPase
4. Increase NaR

Question 24

What are the 3 functions of aldosterone?

Answer 24

Increasing ATPase
Increaseing ENaC
Increasing ability of potassiom to move through K channels

Question 25

Aldosterone promtoes Na ____ and K _____

Answer 25

Na - rabs
K - sec

Question 26

What is the antagonist of aldosterone?

Answer 26

sprionolactone

Question 27

Summary steps of K secretion

Answer 27

1. increase K
2. increase aldosterone
3. Increase K sec in collecting duct
4. increase K excretion

Question 28

What is the main electrolyte of the ICF?

Answer 28

K

Question 29

What is the main electrolyte of the ECF?

Answer 29

Na

Question 30

osmolality

Answer 30

ability to pull water

Question 31

Disturbances in the ____ volume can lead to CV imbalance

Answer 31

ECF

Question 32

Hypernatremia

Answer 32

a dangerous rise in plasma Na
If you only drank sea water