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Flashcards in Reabsorption And Secretion Deck (20):
1

What are the different types of transport mechanisms in the Kidney?

1. Simple Diffusion: down concentration gradient, no protein nor energy

2. Facilitated Diffusion: down concentration gradient, PROTEIN NEEDED, no ATP.

3. Active Transport: AGAINST concentration gradient, PROTEIN and ATP needed

2

Different types of PROTEIN MEDIATED TRANSPORT?

1. Uniport: one molecule crosses the membrane. (Facilitated diffusion)
2. Symport or Cotransport: 2 or more molecules cross membrane in same direction.
3. Antiport or Countertransport: 2 or more molecules move on opposite directions

3

What is Transport Maximum?

1. Maximal rate of transport for a substance when its transport protein is fully saturated

4

What is the only way to ⬆️TM?

1. ⬆️Transport proteins

5

What is primary transport?

1. Active transport in which ATP is involved directly in the transport of a molecule.

Na+-K+ -ATPase

6

What is secondary transport?

1. Active transport in which ATP is involved indirectly in the movement of a molecule across the membrane.

EXAMPLE: Na+K+ATPase necessary for NA+Glucose Contransport or Na+H+ Contratransport

7

These substance have an equal Filtration Load = Excretion Rate?

1. Inulin
2. Mannitol

8

How do you calculate the Filtration Load?

Filtration Load= GFR x Px

Px= free concentration of substance in plasma (mg/ml)

9

How do you calculate Excretion Rate?

Excretion Rate= (Ux)(V)

Ux= urine concentration
V= urine flow rate

10

What is clearance?

The removal of a substance per volume of plasma per unit of time

11

How is Renal Clearance Calculated?

Renal Clearance= (Ux)(V)/ Px

12

What limits Glucose Reabsorption?

TM for glucose.

⬆️Glucose concentration—> TM —> ⬆️Glucose excretion

13

Excellent marker for TM secretion?

1. P-aminohippuric acid (PAH) secretion

14

Percentage of PAH that is always filtered vs secreted?

1. Filtered: 20%
2. Secreted: 80%

15

PAH is an excellent marker for ?

ERPF
(Effective Renal Plasma Flow)

Kidney Blood Flow that DOES NOT go to the glomerulus

16

How do you calculate RBF?

RBF= RPF/1-Hct

17

If 100% of PAH is excreted by the Kidneys, ERPF must equal what?

Renal clearance for PAH.


EPRF= Urinary Concentration PAH x V/Plasma concentration PAH = Clearance PAH

18

Drugs competing for same Organic Anion Transporter? (OAT)

FAPS

1. Furosemide
2. Acetazolamide
3. Penicillin
4. Salicylate

19

Drugs that compete with same Organic Cation Transporter? (OCT)

CAMPA

1. Cimetidine
2. Amiloride
3. Morphine
4. Procainamide
5. Atropine

20

Useful substance to calculate GFR?

Inuline