Brainscape's Knowledge GenomeTM

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


See full index

My Renal > Handling of Sodium > Flashcards

Handling of Sodium Flashcards

1
Q

Which transporter is needed to transport sodium actively

A

Na+/K+ ATPase

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

Which two ions are exchanged for Na+ rather than cotransported?

A

H+ and K+

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

Na+ moves across the apical cell membrane by ______ transport while it moves across the basolateral membrane by _______ transport

A
  • Passive

- Active

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

Na+ is transported across the apical membrane _______ (against/down) its concentration gradient

  • Does it require energy?
  • What is this type of transport called?
A

Down the concentration gradient

It does not require energy

It is secondary active transport

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

Examples of ions/molecules that are reabsorbed/secreted against their concentration gradient across the apical membrane by secondary active transport

A 
Amino acids
glucose
H+ ions
Cl-
lactate
citrate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How is the secretion of H+ ions essential for the reabsorption of bicarbonate

A

When H+ ion are secreted, they combine with bicarb in the lumen of the renal tubule to form carbon dioxide which then diffuses into the cell and then dissociates into H+ ions and bicarb (which are absorbed)

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

Why does the amount of Na+ in the body determine blood volume and ultimately blood pressure?

A

Na+ is the major cation of the ECF and water usually follows it, so if there are a lot of Na+ ions in the ECF there will be a lot of water in the plasma which will increase blood volume which would lead to an increased blood pressure

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

Majority of Na+ is reabsorbed in which portion of the nephron

A

Proximal convoluted tubule

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

Aldosterone can lead to an increase in blood volume & pressure. How?

A

Aldosterone causes an increase in the number of Na+ channels on the luminal surface and an increase in the number of Na+/K+ channels on the basolateral membrane of the principal cells.

This will lead to an increase in the amount of sodium that is reabsorbed which will ultimately pull water in and increase blood volume and pressure

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

Which molecule is the main molecule transported with sodium in the distal convoluted tubule

A

Cl-

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

A [TF/P] ratio greater than 1 indicates what?

Example of an ion/molecule with a ratio >1

A
  • indicates that the amount of the solute in the tubular fluid is greater than the amount in the plasma
  • Eg: creatinine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A [TF/P] ratio less than 1 indicates what?

Example of an ion/molecule with a ratio <1

A
  • indicates that the amount of the solute in the tubular fluid is less than the amount in the plasma
  • Eg: glucose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

A [TF/P] ratio equal to 1 indicates what?

Example of an ion/molecule with a ratio = 1

A
  • indicates that the amount of the solute in the tubular fluid is the same as the amount in the plasma
  • Eg: Na+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the normal value for the fractional excretion of sodium

A

0.5%

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

Loop diuretics affect which transporter and part of the nephron?

What can result from this?

A
  • Affects the Na+/K+/Cl- co transporter in the thick ascending limb
  • this can result in hypo naturemia, kalemia, calcemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which transporter in which part of the nephron is responsible for maintaining paracellular flow of Mg2+ and Ca2+?

A

Na+/K+/Cl- co transporter in the thick ascending limb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Thiazide diuretics affect which transporter and part of the nephron?

What can result from this?

A

Affects the Na/Cl- co transporter in the distal collecting tubule

  • this can result in hyponaturemia
18
Q

the electrochemical gradient in the medulla is created by the action of which transporter in which part of the nephron

A

Na+/K+/Cl- co transporter in the thick ascending limb

19
Q

In a failing kidney, the fractional excretion of Na+ is _______ (greater or lesser)

A

Greater

20
Q

Fractional excretion of sodium (FENa) is used to differentiate between which two most common forms of acute renal failure

A

“prerenal” azotemia and acute tubular necrosis (ATN)

21
Q

The fractional excretion of Na+ is usually greater in which type of acute renal failure

A

acute tubular necrosis (ATN)

22
Q

Why is the fractional excretion of sodium decreased in “prerenal” azotemia

A

Because due to volume loss, the body with try to reabsorb all the Na+ as a compensatory mechanism

23
Q

Equation for fractional excretion of sodium

A

(Na+ excreted / Na+ filtered) * 100

24
Q

Bartter’s syndrome is a salt-wasting disease caused by gene mutations in the Na/2Cl/K cotransporter (NKCC) what may be seen in this condition?

A

very large urinary losses of NaCl and also urinary wasting of Ca2+ and Mg2+

25
Q

Why does sodium excretion increase then return to normal after treatment with Thiazide diuretic

A

Sodium excretion will initially increase and this will cause a decrease in blood volume which activates the renin-angiotensin-aldosterone system which will cause an increase in the sodium transporters in the principal cells and proximal tubule that will once again increase sodium reabsorption

26
Q

What is pressure diuresis?

A

the effect of increased blood pressure to raise urinary volume excretion

27
Q

What is pressure natriuresis?

A

the rise in sodium excretion that occurs with elevated blood pressure

28
Q

How do Thiazides decrease positive free water clearance?

A

Thiazides block Na+/Cl- channels, allowing for more excretion of solutes in the urine and since positive free water clearance is the excess of water free of solutes that is excreted, this volume would decrease because more solutes would now be present

29
Q

How is negative free water clearance ADH’s job?

A

negative free water clearance causes a more concentrated urine because less free water is being excreted, ADH would aid in this because ADH allows for increased reabsorbed of water (ie. less clearance)

30
Q

What is the equation for calculating free water clearance?

A

[ 1 - (urine osmolarity/ plasma osmolarity) ] * vol. of urine

31
Q

What are the two primary physiological regulators of ADH secretion ?

A

The osmolality of the body fluids (osmotic) and the volume and pressure of the vascular system

32
Q

Which two areas of the brain are responsible for secretion of ADH

A

Supraoptic and paraventricular nuclei of the hypothelamus

33
Q

Where in the brain is ADH stored

A

Posterior pituitary

34
Q

Which G protein does ADH stimulate by binding to V2 receptors in the basolaterol membrane of principal cells

A

Gs

35
Q

True or False:

ADH stimulates reabsorption of urea

A

True

The urea transporters (UT-A1 and UT) - are activated by ADH, increasing transport of urea out of the inner medullary collecting duct

36
Q

What is the main issue in central diabetes insipidus

A

Inability to produce or release ADH

37
Q

What are the two possibilities resulting in nephrogenic diabetes insipidus

A

Failure of the countercurrent mechanism to form a hyperosmotic renal medullary interstitium or failure of the distal and collecting tubules and collecting ducts to respond to ADH

38
Q

How can you distinguish central diabetes insipidus from nephrogenic diabetes insipidus?

A

Administer a synthetic form of ADH (desmopressin) and if a decrease in urine volume is not seen then the issue is nephrogenic

39
Q

How can diabetes insipidus (both neurogenic and nephrogenic) lead to hypernaturemia

A

Because of the lack of influence of ADH there will be increased fluid loss which will decrease blood volume, the RAAS will be activated in response and cause decreased sodium excretion leading to hypernaturemia

40
Q

How can Syndrome of inappropriate ADH secretion (SIADH) lead to hyponaturemia?

A

Because of the increased influence of ADH there will be increased fluid retention which will increase blood volume, the RAAS will be deactivated in response and cause increased sodium excretion leading to hyponaturemia

41
Q

What is urine specific gravity a measure of?

A

It is a measure of the weight of solutes in a given volume of urine

My Renal (9 decks)

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