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Flashcards in Reabsorption And Secretion Deck (20)
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1
Q

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

A
  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
Q

Different types of PROTEIN MEDIATED TRANSPORT?

A
  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
Q

What is Transport Maximum?

A
  1. Maximal rate of transport for a substance when its transport protein is fully saturated
4
Q

What is the only way to ⬆️TM?

A
  1. ⬆️Transport proteins
5
Q

What is primary transport?

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

Na+-K+ -ATPase

6
Q

What is secondary transport?

A
  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
Q

These substance have an equal Filtration Load = Excretion Rate?

A
  1. Inulin

2. Mannitol

8
Q

How do you calculate the Filtration Load?

A

Filtration Load= GFR x Px

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

9
Q

How do you calculate Excretion Rate?

A

Excretion Rate= (Ux)(V)

Ux= urine concentration 
V= urine flow rate
10
Q

What is clearance?

A

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

11
Q

How is Renal Clearance Calculated?

A

Renal Clearance= (Ux)(V)/ Px

12
Q

What limits Glucose Reabsorption?

A

TM for glucose.

⬆️Glucose concentration—> TM —> ⬆️Glucose excretion

13
Q

Excellent marker for TM secretion?

A
  1. P-aminohippuric acid (PAH) secretion
14
Q

Percentage of PAH that is always filtered vs secreted?

A
  1. Filtered: 20%

2. Secreted: 80%

15
Q

PAH is an excellent marker for ?

A

ERPF
(Effective Renal Plasma Flow)

Kidney Blood Flow that DOES NOT go to the glomerulus

16
Q

How do you calculate RBF?

A

RBF= RPF/1-Hct

17
Q

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

A

Renal clearance for PAH.

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

18
Q

Drugs competing for same Organic Anion Transporter? (OAT)

A

FAPS

  1. Furosemide
  2. Acetazolamide
  3. Penicillin
  4. Salicylate
19
Q

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

A

CAMPA

  1. Cimetidine
  2. Amiloride
  3. Morphine
  4. Procainamide
  5. Atropine
20
Q

Useful substance to calculate GFR?

A

Inuline