Nephron Physiology

Question 1

Where does PTH allow for Phosphate Excretion?

Answer 1

Early PCT

Question 2

Where does AT2 stimulate Na+/H+ exchange?

Answer 2

Early PCT

Question 3

Role of Thin ascending loop?

Answer 3

Make Urine Hypertonic

Question 4

Role of Thick ascending loop?

Answer 4

Make Urine Hypotonic

Question 5

Receptor in Thick ascending Loop?

Answer 5

NKCC

Question 6

Makes urine most dilute (hypotonic)?

Answer 6

Early DCT

Question 7

Where does PTH induced Ca2+ absorption occur?

Answer 7

Early DCT

Question 8

ADH—acts at V2 receptor to do?

Answer 8

insertion of aquaporin H2O channels on apical side.

Question 9

Principal Cells regulates

Answer 9

K+ and Na+

Question 10

å-Intercalated cells secrete? Reabsorb?

Answer 10

Acid (H+)

Bicarb

Question 11

Highest TF/P=?

Answer 11

PAH

Question 12

Which substances have a TF/P>1?

Answer 12

PAH, Inulin, Creatinine, Urea, Cl-

Question 13

Lowest TF/P?

Answer 13

Glucose

Question 14

TF/P closest to 1?

Answer 14

Na and K+

Question 15

What three things increase Renin? Who is it sensed by?

Answer 15

Decreased BP (JG cells)
Decreased Na+ delivery (Macula densa cells)
Increased Symp. TOne (B1 receptors)

Question 16

AT2 does two things?

Answer 16

1. Tenses Angios (Vasoconstriction and Constriction of efferent arteriole)
2. Increase Na and H20 reabsorption+ thirst via hypothalamus

Question 17

Na+H+ activity in the PCT can lead to?

Answer 17

Contraction alkalosis

Question 18

How does ANP and BNP affect RAAS system?

Answer 18

Relaxes vascular smooth muscle via cGMP=>increased GFR and decrease Renin

Question 19

What primarily regulates Osmolarity?

Answer 19

Vasopressin

Question 20

What primarily regulates ECF volume and Na+ content?

Answer 20

Aldosterone

Question 21

JG cells secrete renin in response to?

Answer 21

Low Renal BP

Increased Symp (B1)

Question 22

Macula densa cells secrete renin in response to?

Answer 22

Decreased Na+ delivery

Question 23

Macula densa cells sense Increased NaCl=Increased GFR and release what?

Answer 23

Adenosine=>to vasoconstrict

Question 24

B-BLockers decrease BP by blocking?

Answer 24

B1 stimulation in JG cells

Question 25

In hypoxic states, EPO is secreted by which cells of the kidney?

Answer 25

interstitial cells in peritubular capillary bed

Question 26

PCT cells convert 25-OH vitamin D to 1,25- (OH)2 vitamin D (active form) via?

Answer 26

1α-hydroxylase

Question 27

PGE is produced by?

Answer 27

Paracrine secretion

Question 28

ANP secretion in response to increased atrial pressure leads to?

Answer 28

Na+ loss and volume loss

Question 29

PTH is stimulated via 3 ways?

Answer 29

1. Decreased plasma [Ca2+] 2. Increased 􏰀plasma [PO43–], 3. Decreased 􏰁plasma 1,25 (active form)

Question 30

PTH Does 4 Things, what are they?

Answer 30

1. Increased 􏰀[Ca2+] reabsorption (DCT), 􏰁2. Decreased [PO43–] reabsorption (PCT), and 3. Increased 􏰀1,25-(OH)2 D3 production 4. 􏰀Ca2+ and PO43– absorption from gut via vitamin D

Question 31

Vasopressin is secreted in response to?

Answer 31

Increased plasma osmolarity and decreased volume=>increases number of AQ porins

Question 32

A Patient With Hyperkalemia?

Answer 32

DO LAβS

Question 33

DO LAβS

Answer 33

``` Digitalis (blocks Na+/K+ ATPase) HyperOsmolarity Lysis of cells (e.g., crush injury, rhabdomyolysis, cancer) Acidosis β-blocker High blood Sugar (insulin deficiency) ```

Question 34

Insulin shifts K+ into cells causing?

Answer 34

Hypokalemia