Renal - Pt 4 Reabsorption/Secretion/Hormones Flashcards

1
Q

[] % of reabsorption occurs in the TAL.

A

25%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

There are no [] reabsorption in the TAL due to true tight junctions.

A

Paracellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

TAL Reabsorption: Apical Membrane

  1. [] (NKCC) symporters present in the apical membrane. This transporter brings the 3 ions [] the cell.
  2. [] leak channels allow K+ to leak out of the cell.
A
  1. Na+/K+/2 CL- (NKCC) symporters present in the apical membrane. This transporter brings the 3 ions into the cell.
  2. Potassium leak channels allow K+ to leak out of the cell.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  1. Resorption in the TAL differs from the PCT in that water [] follow the electrolytes as they are reabsorbed.
  2. The TAL of the loop of Henle is always [] to water.
A
  1. cannot
  2. impermeable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  • [] inhibits the NKCC transport in the TAL
  • This causes urine output to dramatically []
  • Urine sodium amounts []
    • However the body tries to [] Na+ past hthe TAL
  • Plasma Potassium Amounts drastically []
A
  • Furosemide inhibits the NKCC transport in the TAL
  • This causes urine output to dramatically increase
  • Urine sodium amounts increase
    • However the body tries to reabsorb Na+ past the TAL
  • Plasma Potassium Amounts drastically decrease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

TAL Reabsorption: Basolateral Side

  1. [] and [] leak channels allow the ions to to be reabsorbed through the basolateral membrane
  2. Na+/K+ pumps move Sodium acorss the basolateral membrane for [].
A
  1. Cl- and K+ leak channels allow the ions to to be reabsorbed through the basolateral membrane
  2. Na+/K+ pumps move Sodium acorss the basolateral membrane for resorption.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T/F

Active transport moves Na+ into the interstitial fluid of th descending limb of the loop of Henle.

A

False

There is not active transport in the descending limb of the loop of Henle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  • In the descending loop of Henle, [] transport of solutes does not readily occur and there is limited [] to sodium and chloride ions.
  • However, [] is freely permeable to move via osmosis to the [] fluid.
A
  • In the descending loop of Henle, active transport of solutes does not readily occur and there is limited permeability to sodium and chloride ions.
  • However, water is freely permeable to move via osmosis to the interstitial fluid.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The medullary gradient is formed by the [] cotransporters in the [].

A

The medullary gradient is formed by the NKCC cotransporters in the TAL.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The osmolarity of fluids in the interstitial space of the cortex is approximately [] mOsm/L, while the osmolarity within the medulla can climb up to values of approx [] mOsm/L.

A

300 mOsm/L

1200 mOsm/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  1. The loop of Henle is associated with the Counter-current [] system
  2. The vasa recta participate in a diffusion process called the counter current [] system.
A
  1. Multiplier
  2. Exchange
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

T/F

No reabsorption happens in the DCT.

A

False

Roughly 5% of solutes still need to be reabsorbed around the DCT…but most solutes are absorbed in the PCT and TAL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  1. The [] is the main site of hormone reabsorption regulation
  2. The 2 hormones involved are [] and []
A
  1. DCT
  2. Aldosterone and ADH (anti-diuretic Hormone)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  1. Aldosterone controls [] reabsorption
  2. ADH controls [] reabsorption
A
  1. Sodium
  2. water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. The largest percentage of secretion occurs in the [] and [] []
  2. This is because [] junctions are not true tight junctions in the [], but they are in the DCT. So, when something is [] in the DCT, it stays secreted and cannot leak back into the interstitial fluid.
A
  1. The largest percentage of secretion occurs in the DCT and collecting duct
  2. This is because tight junctions are not true tight junctions in the PCT, but they are in the DCT. So, when something is secreted in the DCT, it stays secreted and cannot leak back into the interstitial fluid.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Most of the secretion that occurs in the DCT and Collecting Duct is by [] transport via [] carriers.

A

active

protein

17
Q

Potassium is secreted in the [] DCT and collecting duct via a sodium/potassium ATPase embedded in the [] membrane, and a [] [] channel in the [] membrane.

A

Potassium is secreted in the late DCT and collecting duct via a sodium/potassium ATPase embedded in the basolateral membrane, and a K+ leak channel in the apical membrane.

18
Q
  • Water is [] by the hormone ADH (also called []) from the [] [] gland.
  • ADH leads to the insertion of proteins called [] into the mebranes of the late DCT and Colecting Ducts…allowing for the [] of water.
A
  • Water is saved by the hormone ADH (also called vasopressin) from the posterior pituitary gland.
  • ADH leads to the insertion of proteins called aquaporins into the mebranes of the late DCT and Colecting Ducts…allowing for the reabsorption of water.
19
Q
  • Sodium is saved by the hormone [] from the adrenal glands.
  • This hormone [] the number and activity of sodium/potassium pumps in the tubule allowing for an increase in sodium []and potassium [].
A
  • Sodium is saved by the hormone aldosterone from the adrenal glands.
  • This hormone increases the number and activity of sodium/potassium pumps in the tubule allowing for an increase in sodium reabsorption and potassium secretion.
20
Q

The release of ADH is controlled by cells in the hypothalamus called [].

A

Osmoreceptors

21
Q

Osmoreceptors and ADH

  • Osmoreceptors are receptive to their own cell []
  • If the oncentrationf of extracellular fluid becomes high (like during []) –> the cell []—> increass rate of action potentials –> [] release of ADH
A
  • Osmoreceptors are receptive to their own cell size
  • If the concentration of extracellular fluid becomes high (like during dehydration) –> the cell shrinks —> increases rate of action potentials –> increases release of ADH
22
Q

An [] in the stretch of baroreceptors will lead to a [] secretion of ADH

A

An increase in the stretch of baroreceptors will lead to a decrease secretion of ADH

23
Q

What 2 mechanisms did we learn of that can effect the release of ADH from the posterior pituitary?

A

Osmoreceptors - stimulation causes increased ADH

Baroreceptors - stimulation causes decreased ADH

24
Q

If both the baroreceptors and osmoreceptors are signaling the posterior pituitary for ADH, the [] will have a greater effect.

A

Osmoreceptors

25
Q
  • ADH travels through the bloodstream and binds to [] receptors in the late DCT and CD.
  • This stimulates the insertion of [] channels into the apical membrane and allows for [] of water.
A
  • ADH travels through the bloodstream and binds to V2 receptors in the late DCT and CD.
  • This stimulates the insertion of aquaporin-2 channels into the apical membrane and allows for reabsorption of water.
26
Q

Other effects of ADH:

  • Stimulates []
  • Increases activity of the[] symporter in the [] [] limb of hte loop of Henle
  • Increaes nephron permeability to [] in the medullary [] [].
A
  • Stimulates thirst
  • Increases activity of the NKCC symporter in the thick ascending limb of hte loop of Henle
  • Increases nephron permeability to urea in the medullary collecting duct.
27
Q

ADH also leads to the insertion of urea transporters, called [] in the medullary [] [].

A

ADH also leads to the insertion of urea transporters, called ureaporins in the medullary collecting duct.

28
Q

Production of Hypo-Osmotic Urine:

  • Drink H2O —> decrease plasma osmolarity —> [] osmoreceptor firing —> [] ADH release —> decrease H2O reabsorption in Late DCT and Collecting Duct —> [] urine osmolarity & [] urine volume —> [] plasma osmolarity
A

Drink H2O —> decrease plasma osmolarity —> decrease osmoreceptor firing —> decrease ADH release —> decrease H2O reabsorption in Late DCT and Collecting Duct —> decrease urine osmolarity & increase urine volume —> increase plasma osmolarity

29
Q

Production of Hyper-Osmotic Urine

  • Deprived of H2O —> increase plasma osmolarity —> [] osmoreceptor firing —> []ADH release —> increase H2O reabsorption in Late DCT and Collecting Duct —> [] urine osmolarity & [] urine volume —> [] plasma osmolarity
A

Deprived of H2O —> increase plasma osmolarity —> increase osmoreceptor firing —> increase ADH release —> increase H2O reabsorption in Late DCT and Collecting Duct —> increase urine osmolarity & decrease urine volume —> decrease plasma osmolarity