Proximal Tubule Phys

Question 1

Amount of blood entering the glomerulus via the afferent

Answer 1

600 ml/min and around 475 leaves so 125 ml/min is in the filtrate

Question 2

T/F 2/3 of all the filtered solutes and water are reabsorbed within the PT?

Answer 2

True

Question 3

Normal BUN

Answer 3

7-20

Question 4

Normal Bicarb

Answer 4

22-28

Question 5

Normal Cr-

Answer 5

Females: 88-128 ml/min
Males: 97-137 ml/min

Question 6

Normal Phosphorus

Answer 6

2.4-4.1 mg/dL

Question 7

Primary active transport

Answer 7

ATPases

Question 8

Secondary active transport

Answer 8

One solute moves down its EC gradient which provides the energy for another to cross against its gradient

Question 9

Na/K ATPase pump is located where?

Answer 9

ONLY on the basolateral membrane; it kicks 3 Na+ out and brings 2 K+ in
Is an ACIVE energy requiring pump

Question 10

SGLT?

Answer 10

Sodium-glucose linked transporters
1 and 2
90% of glucose is reabsorbed in the PT via SGLT 2 (1:1)

Question 11

Na+/H+ antiporter is driven by:

Answer 11

1. Increased CO2
2. Increased AG II
3. Increased SNS
4. Decreased pH

Question 12

Na+/glucose transporters:

Answer 12

Normally 100 % of all glucose is filtered in the PT
It is a transporter
Have a saturation point= transport maximum Tm

Question 13

Transport maximum

Answer 13

Saturation is maxed for glucose= 15mM glucose

Question 14

Why is glucosuria not a test for DM?

Answer 14

Transport mediated- some disorder or disease which wipes out the transporter
Normal serum glucose with glucosuria= PT transporter problem

Question 15

Purpose of formate?

Answer 15

Recycling to bring Cl- into the cells

Question 16

CrCl-

Answer 16

Estimate of GFR

Misled on the high end

Question 17

MDRD

Answer 17

Predictor of the true GFR b/c its not dependent in the same way on Cr-
Standardized to body size so if large or small it’ll be off
MDRD is good for long term changes

Question 18

How much bicarb is reclaimed in the PT?

Answer 18

80% is reclaimed

Question 19

PT reabsorption

Answer 19

66% of Na+, Cl- and H2O is reabsorbed

100% of glucose and 80% of HCO3- is reabsorbed in the PT

Question 20

If you take a toxin would you rather it be polar or nonpolar?

Answer 20

Polar as it is charged and cannot be reabsorbed from the lumen and is urinated out

Question 21

Liver transformation?

Answer 21

Adds charges onto things so it’ll get urinated out
Liver = Cyt P450
If this is the normal pathway to charge something and it is inhibited it will be reabsorbed= higher levels= must decrease the dose.

Question 22

Why do the kidneys filter so much per day?

Answer 22

To get rid of the stuff we don’t need

Question 23

WOA and WOB

Answer 23

Both secreted and reabsorbed

Question 24

What keeps WOA’s from being excreted?

Answer 24

Monocarboxylic acids are tagged and move into the cell via MCA channels