Renal Transport Mechanisms

Question 1

Describe the Proximal Tubule Absorption

Answer 1

1) All Glucose and Amino Acids
2) Most other filtered substances should be resorbed here

Question 2

How is Na+ Reabsorbed into the blood after entering the Cell?

Answer 2

Na+/K+ Pump

Question 3

How does Na+ cross tthe cells apical border in the Proximal Tubule?

Answer 3

1) Na/H+ Exchanger
2) SGLT symporter

Question 4

How does Glucose get resorbed from the basolateral membrane

Answer 4

1) GLUT

Question 5

How is water resorbed?

Answer 5

Bulk Flow

Question 6

How does H20 enter cells?

Answer 6

AQP channels

Question 7

Decreased ECV will cause h20 to be ____

Answer 7

resorbed

Question 8

Increased ECV will cause h2o to ____

Answer 8

Not be reabsorbed

Question 9

Can H20 be reasorbed in the TAL?

Answer 9

NO; TAL is impermable to H2O

Question 10

Which ion gets reabsorbed the most in the TAL?

Answer 10

Mg2+

Question 11

TAL is a important site for resorption of ____ ___ ___ ____

Answer 11

N, K, Ca, Mg

Question 12

Describe the function of NKCC Channel in the TAL

Answer 12

1) Sympoter of 2Cl-, K, Na into the cell
2) Na+ and Cl- can then get reabsorbed into the blood
3) K+ can either get reabsorbed or it can be secreted back into the tubule lumen via ROMK
4) If secreted it will cause increased + charge which leads to increased charge
5) Drives Na+, Ca2+, K+ and Mg2+ to be transported via paracellularly

Question 13

ROMK is located on the ___ membrane

Answer 13

Basolateral

Question 14

Which area of the nephron will reabsorb the least amount of solutes?

Answer 14

Distal Tubule

Question 15

What cell types are present in the Distal Tubule?

Answer 15

Alpha - intercalated cells

Beta-intercalated cells

Principal Cels

Question 16

Which hormones are involved with the distal tubule

Answer 16

1) Aldosterone
2) ADH

Question 17

What is the most important site of regulation of the Nephron?

Answer 17

Distal Tubule

Question 18

What do principal cells reabsorb and secrete?

Answer 18

1) Reabsorb: Na+ and H20
2) Secrete: K+

Question 19

What do alpha intercalated cells reabsorb and secrete?

Answer 19

1) K+ and HCO3-
2) H+

Question 20

What do B-intercalated cells reabsorb and secrete?

Answer 20

1) H+ and Cl-
2) K+ and HCO3-

Question 21

Which part of the Distal Tubule is relatively impermeable to water?

Answer 21

Distal Convolulted Tubule

Question 22

With in the DCT NaCL is transported into the cell via

Answer 22

NCC channel

Question 23

NCC is a ___ and ____ cotransporteer

Answer 23

NA+ and Cl-

Question 24

NCC cotransporter is ___ sensitive

Answer 24

Thiazide

Question 25

Ca2+ crosses the apical membrane in the DCT via what channel?

Answer 25

TRPV5

Question 26

Ca2+ crosses the basolateral membrane of the DCT via \_\_\_\_

Answer 26

NCE

Question 27

Describe the NCE

Answer 27

1) NCE= Na+ Ca2+ exchanger 2

Question 28

In the Late DT and CD Na+ principal cell via...

Answer 28

ENaC

Question 29

What hormone increases the amount of ENaC and Na/K ATPase in the CT

Answer 29

Aldosterone

Question 30

1) Describe how Principal Cells and B-intercalated cells secrete K+

Answer 30

1) Na+/K+ ATPase moves K+ into cell from interstiatial fluid 2) Passive diffusion of K out of cell into tubular lumen via ROMK

Question 31

Describe how a-intercalated cells reabsorb K+

Answer 31

1) H-K ATPase moves K into the cells from the tubular lumen 2) K+ diffuses across the basolateral membrane through K channels

Question 32

What are the most important factors that stimulate sodium reabsorption?

Answer 32

1) Na+ deficiency 2) low Na+ diet 3) Hyponatremia 4) Na+ loss through severe diarrhea

Question 33

What are the most important factors that stimulate sodium secretion

Answer 33

1) Hypernatremia 2) ANP 3) Renal Prostaglandins

Question 34

What are the most important factors that stimulate potassium secretion in PRincipal cells and B-intercalated cells

Answer 34

1) Increased serum concentration of potassium 2) Aldosterone

Question 35

What is the most important factors that cause K+ reabsortion in alpha-intercalated cells

Answer 35

1) K+ 2) Low K+ diet 3) Hypokalemia 4) K+ loss through severe diarrhea

Question 37

What detect the change in osmolarity so that ADH can be secreted?

Answer 37

Osmoreceptors in the Hypothalamus and Liver

Question 38

Where does ADH increase water permeability?

Answer 38

Late DT and CD via Insertion of Aquaporins

Question 39

How does ADH increase Urea Permeability?

Answer 39

Inner Medullary Collecting Ducts (IMCD)

Question 40

Describe the influence that ADH has on NKCC2 channels

Answer 40

1) Increases activity in the TAL

Question 41

Aquaporin-2 channel is inserted into the apical membrane of principal cells via ____ stimulation

Answer 41

ADH

Question 42

Can Urea be reabsorbed in the CCD?

Answer 42

NO! Water can and this sets up a gradient for Urea to dissuse passsively ot of tuble in IMCD

Question 43

Vasa Recta prevent the _____ form being dissipated

Answer 43

Hyperosmolarity

Question 44

Increased RBF or Hypertension will lead to _____ urine

Answer 44

dilute

Question 45

Calculate Osmolar Clearance

Answer 45

Cosm = Uosm \* V / Posm

Question 46

How do you calculate Free Water Clearance

Answer 46

Ch2o = V- Cosm

Question 47

Describe what occurs when CH2O is negative

Answer 47

Excess solutes are removed , water conservation

Question 48

Describe what occurs when CH2O is positive

Answer 48

Water is being excreted forming dilute irine, water excess

Question 49

Describe Obligatory Urine Volume

Answer 49

How much urine we have to eliminate per day

Question 50

How do you calculate OUV

Answer 50

Minimum solute excretion per day / max urine concentrating ability

Question 51

Define Diuresis

Answer 51

Kidneyhs reabsorb solutes and fail to reabsorb water. High volume, dilute urine Low medullary solute concentrations

Question 52

Antidiuresis requires high ___ and High ____ of renal medullary interstitial fluid.

Answer 52

1) ADH 2) Osmolality

Question 53

Define Natriuresis

Answer 53

Excretion of large amount of sodium in urine espicially disproportional to exretion of water

Question 54

Causes of Natriuresis

Answer 54

1) Drugs 2) Hormones (ANP) 3) Significantly elevated renal perfusion pressure (pressure natriuresis