Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chronic Kidney Failure > Tubular function 2 > Flashcards

Tubular function 2 Flashcards

1
Q

Is filtrate hyper, hypo, or isosmotic with plasma after passing PCT?

A

Isosmotic

goes into loop of henle

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

Which limb of Loop of Henle is permeable to water? What is the aquaporin channel responsible?

A

Descending thin limb

AQP1

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

Descending limb is less permeable to what 2 molecules?

A

NaCl and urea

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

What is reabsorbed in ascending limb? 3 molecules.

A

Na+, Cl- and K+

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

Thin ascending limb – passive? Active? How much?

A

Passive
little reabsorption
mostly Na+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The protein channel that transports 3 molecules? Where do they go? Which membrane are they located on?

A

Symporter protein, located on apical membrane.

Go into cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does Cl- leave the cell?

A

Passive diffusion through basolateral Cl- channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

About how much (Minority/majority?) of K+ leaves the cell. To which side? How? What effect does this have?

A

Majority leaks back into lumen via apical K+ channels.
Tubular lumen becomes +ve charge
Drives paracellular diffusion of Na+, Ca2+ and Mg2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does Na+ leave the cells?

A

Sodium pump via electrochemical gradient

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

What are 2 consequences of the ascending loop of Henle being impermeable to water?

A

Osmolality of tubular fluid will decrease (solutes removed but water can’t move with it - more water in tubular fluid)
Interstitual fluid gets more concentrated (hyperosmotic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which protein channel do loop diuretics work on?

A

Sodium comes in by co-transport with K+ and 2Cl- (sodium pump?)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is the interstitial fluid of medulla hyper, iso, or hypoosmotic as a result of the actions of the ascending limb of loop of henle? What is the effect of this?
Filtrate entering the DCT is now hyper, hypo, or isosmotic?

A

Hypoosmotic when it enters the DCT (more dilute)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens in the early DCT?

What are the ions involved?

A

Continues active dilution
Impermeable to water
Na+, Cl-, Ca2+, Mg2+, K+, H+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which protein channel do Thiazides act on?

A

Sodium and chloride symporter proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are 2 buffer naturally present in the luminal fluid?

DCT

A

HPO42- or NH3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are 2 cells present on the late DCT? What do each of them do?

A

Principle cells - reabsorb Na+ and water, secrete K+

Intercalated cells - secrete H+, reabsorb HCO3- and K+

17
Q

What are 3 hormones that regulate kidney function? What do each of them do?

A

Aldosterone: INCREASE Na+ reabsorption, K+ and H+ secretion
ANP: DECREASE Na+ reabsorption
ADH/vasopressin: INCREASE H2O and urea reabsorption

18
Q

Where is aldosterone secreted from?

A

From zona glomerulosa of adrenal cortex

19
Q

Explain the 3 functions of Aldosterone

A
  1. Enhances Na+ reabsorption - inc number and activity of apical Na+ channels, and activity of basolateral Na+ pump.
  2. Enhances K+ secretion in principal cells: Inc, number and activity of apical K+channels, basolateral Na+ pump and Na+ reabsorption
  3. Enhances H+ secretion in intercalated cells - stimulates H+ATPase pump.
20
Q

Is the DCT and Collecting duct naturally permeable or less permeable to water?

A

naturally less permeable

21
Q

What does ADH do? Which aquaporin does it stimulate?

A

facilitates reabsorption of water

activates AQP2

22
Q

Explain the biochemical pathway of ADH action. What is the secondary messenger?

A

acts on receptors in basolateral membrane

uses cAMP as secondary messenger to insert AQP2 on apical side

23
Q

Where are AQP3 and 4 located?

A

basolateral membrane

24
Q

What is the 2nd key role of ADH?

A

increases permeability of IMCD to urea (inner medullary collecting duct)

25
Q

Normally, what parts of the nephron are permeable to urea?

A

proximal tubule and inner medulla

26
Q

What is the name of the transporter than allows urea transport in the presence of ADH?

A

Urea transporter (UT1)

27
Q

Urea recycling: which parts of the nephron does urea diffuse into?

A

eventually into descending and ascending lims of loop of henle

28
Q

What are 3 disorders of ADH?

A

Diabetes insipidus (inadequate secretion or response to ADH -> polyuria, polydipsia)
SIADH (inappropriate secretion of ADH -> hyponatremia)
Nocturnal enuresis/bed-wetting (ADH secretion in circadian rhythm increases at night)

Chronic Kidney Failure (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions