Brainscape's Knowledge GenomeTM

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


See full index

BIOL 204 > Lecture 14 -- Review questions > Flashcards

Lecture 14 -- Review questions Flashcards

1
Q

in which part of the nephron does glomerular filtration occur?

A

glomerulus

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

what is the overall purpose of tubular reabsorption?

A

reclaiming what the body needs to keep

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

in which part of the nephron does most reabsorption occur (essential solutes, electrolytes, water)?

A

PCT

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

which part of the nephron usually reabsorbs the most water and sodium?

A

PCT

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

what is meant by tubular secretion?

A

process of selectively moving substances from the blood into the filtrate

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

what is the difference b/n paracellular and trans cellular transport routes across tubule cells?

A

paracellular – substances cross tubule cells by passing the gap b/n them

transcellular – substances cross tubule cells by directly passing thru them

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

which structures must the substances inside the renal tubule cross if they want to be reabsorbed by the peritubular capillaries?

A

lumen –> apical membrane –> cytosol in tubule cell –> basolateral membrane –> interstitial fluid –> endothelial cell of capillary –> blood in peri tubular capillary

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

what does Tm stand for? When is the Tm reached?

A

Tm = transport maximum == max rate of reabsorption

Tm is reached when transporters are saturated

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

which factor limits the amount of solute the renal tubule can reabsorb and, thus, the Tm?

A

of transport proteins

(limited number of transport proteins –> limit the amount of solute that the renal tubule can reabsorb)

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

which pumps generate a strong concentration gradient for sodium reabsorption in the renal tubule?

where is it located (apical or basolateral membrane)?

A

Na+/K+ pumps

located in basolateral membrane on the side facing interstitial fluid

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

in which renal tubule segment is sodium reabsorbed with other solutes?

A

PCT

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

what does Na+/H+ anti porter (Na+/H+ exchanger-3) do in the renal tubule?

does it transport Na+ out or toward the tubule cell?

In which segment?

A

transports Na+ from filtrate into PCT
transports H+ from PCT out into filtrate

anti porter is located on apical membrane of PCT facing filtrate

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

which hormone stimulates the proximal tubule Na-H anti porter?

A

angiotensin-II

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

what do the Na+/K+ pumps do?

does it transport Na+ into the interstitial fluid or into inside the tubule cell?

how about K+?

A

generate strong [] gradient for Na+ reabsorption

transports Na+ out of tubule cell into interstitial fluid

transports K+ into tubule cell from interstitial fluid

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

what does SGLT stand for?

in which renal tubule segment can you find it?

what is its function?

A

Na+/glucose transporters

PCT

bring Na+ from filtrate into PCT with other solutes like glucose and amino acids

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

which segment of the nephron loop is permeable to water?

A

descending limb

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

which segment of the nephron loop is impermeable to water?

A

ascending limb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

which segment of the nephron loop is permeable to solutes?

A

ascending limb

19
Q

which segment of the nephron loop is impermeable to solutes?

A

descending limb

20
Q

why is the ascending limb of the nephron loop considered “the diluting segment of the nephron?”

A

solutes leave the filtrate at the ascending limb –> tubular fluid becomes diluted

21
Q

how many ions of potassium and chloride are cotransported with sodium in the thick ascending loop of Henle?

A

1 Na+
1 K+
2 Cl-

are all cotransported together

22
Q

what does Na+/K+/2 Cl- cotransporter do? (direction of ion movement)

A

moves ions out of the filtrate and into the blood

23
Q

in which type of kidney tubule are the Na+ - K+ - 2 Cl- symptorters (NKCC2) found?

A

thick ascending loop of Henle

24
Q

what is the function of the Na+ - Cl- cotransporters? (direction of ions movement)

where are they located?

A

moves Na+ and Cl- from urine back into DCT

25
Q

where are the principal cells in the renal tubule, and what is their primary function? (ions reabsorbed and secreted)

which hormone controls these processes?

A

located in the cortical collecting duct

adjust [electrolyte] by:
- reabsorbing Na+ and H2O
- secreting K+

aldosterone

26
Q

where are the type A intercalated cells located in the renal tubule, and what are 2 of their primary functions?

(ions reabsorbed and secreted)

A

located in the DCT

pH homeostasis (acid-base regulation)
- reabsorbing K+
- secreting H+

27
Q

how does the medullary portion of the collecting duct contribute to the hyper osmotic medullary interstitial fluid =

which solute diffuses from the CD and contributes to the medullary osmotic gradient?

A

reabsorbing urea

28
Q

which hormone controls water reabsorption and, therefore, urine concentration in the CD?

A

ADH

29
Q

which 2 factors allow the kidney to produce concentrated (hypertonic) urine?

A

medullary osmotic gradient:
- ISF of renal medulla has a high osmolarity - >
water gets reabsorbed and causes the urine to be more concentrated

ADH acting on DCT and CD:
- more aquaporins in DCT and CD –>
greater water permeability in DCT and CD –> more water gets reabsorbed and causes the urine to be more concentrated

30
Q

to produce concentrated urine, do you need to reabsorb more or less water?

A

you need to reabsorb more water

water leaves urine –> urine is more concentrated

31
Q

where can you find more concentrated interstitial fluid, deep in the medulla or the cortex?

A

deep in the medulla

32
Q

which 3 mechanisms help with creating and/or maintaining the medullar osmotic gradient?

A

(1) countercurrent multiplier

(2) recycling of urea

(3) countercurrent exchanger

33
Q

where does the countercurrent multiplier occur?

A

nephron loops of juxtamedullary nephrons

34
Q

why is the countercurrent multiplier system called a “multiplier”?

A

it multiplies the osmolarity deep in the medulla

by recapturing salt and returning it to the deep medullary tissue

35
Q

what does “countercurrent” mean regarding the countercurrent multiplier system?

A

filtrate flows in opposite direction (countercurrent) thru 2 adjacent parallel sections of a nephron loop

36
Q

Figure 1 – in this part of the nephron, water is drawn from the tubular fluid thru aquaporins, following an osmotic gradient created by which ion?

A

Na+

37
Q

in which segment of the nephron loop is the tubular fluid more concentrated in solutes?

A

bottom of the nephron loop

38
Q

Figure 2 – why are sodium ions leaving the filtrate at this point of the nephron loop and not before?

A

[NaCl] is the highest at this point

39
Q

what is responsible for increasing the interstitial fluid’s osmolarity of the medulla: pumping sodium outside the tubule or water?

A

pumping sodium outside the tubule

40
Q

what is the difference b/n countercurrent exchange and countercurrent multiplier?

A

countercurrent multiplier – creates the medullary gradient (causes medulla to have a much higher osmolarity)

countercurrent exchange – preserves the medullary gradient

41
Q

what are the purposes of the countercurrent exchange?

A

(1) prevent rapid removal of salt from the medullary interstitial space

(2) removing reabsorbed water

42
Q

what is the difference b/n obligatory vs. facultative water reabsorption?

A

obligatory – water is “obliged” by osmosis to follow solutes that have been reabsorbed

facultative – water is reabsorbed according to body’s needs –> regulated by hormones

43
Q

in which segments of the renal tubule does obligatory water reabsorption take place?

and facultative?

A

85% of water reabsorption –> PCT and descending limb of loop of Henle

15% of water reabsorption –> DCT and CD

44
Q

which parts of the renal tubule are considered aldosterone-sensitive?

A

distal nephron:

late DCT
connecting tubule
collecting duct

BIOL 204 (35 decks)

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