Brainscape's Knowledge GenomeTM

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


See full index

c > renal structure and function 2 > Flashcards

renal structure and function 2 Flashcards

1
Q

define osmosis

A

the tendency of water to move from a more dilute solution to a more concentrated solution

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

define osmotic pressure

A

the tendency of a solution to take in water by osmosis

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

define osmol

A

the unit defining the osmotic strength of a solution

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

what is the osmolarity of the blood plasma?

A

300mOsm

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

how much of the blood is in the capillaries and veins?

A

65%

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

which sensors regulate blood volume?

A

volume sensors - neuronal and hormonal

sodium sensors

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

where are neuronal volume sensors found?

A

sensory fibres found mostly in RA as well as LA (less in LA)

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

how do neuronal volume sensors work?

A

act as stretch receptors - as venous return increases, they stretch more
signals volume of blood return to the heart/minute via the vagus

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

what are hormonal volume sensors and where are they found?

A

specialized muscle cells also found in the RA and IVC

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

what can cause increase stretching of hormonal volume sensors?

A

increased preload bc of increased blood volume

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

in response to stretch. what do hormonal volume sensors release?

A

atrial natriuretic peptide

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

explain how hormonal volume sensors help in restoring blood volume

A

release ANP –> decreases Na+ reabsorption in DCT –> increased water loss –> reduces blood volume –> brings it back to normal

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

what cells secrete BNP and when?

A

ventricular muscle cells when ventricles are overstretched e.g in heart failure

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

what do ANP and BNP do?

A

increase sodium excretion

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

how does the hypothalamus attach to the pituitary gland?

A

pituitary stalk

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

what sensors are found in the hypothalamus?

A

sensors that monitor osmotic strength of the blood

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

what is the hypothalamus?

A

a structure composed of tiny nuclei packed together

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

what are the two important nuclei involved in water balance?

A

the supraoptic and paraventricular nuclei.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how does the hypothalamus cause ADH secretion?

A

contains nuclei which contain receptors that measure osmotic pressure
also receive info from blood volume receptors via relays in the brainstem NTS

Send axons down pituitary stalk to end as secretory terminals on capillaries in the PPG  axons secrete ADH

20
Q

what is ADH?

A

antidiuretic hormone - peptide containing 9 amino acids

21
Q

what stimulates ADH release?

A

high blood solute concentration

sympathetic arousal

22
Q

which sensors detect blood sodium levels?

A

sodium detectors in the kidney

23
Q

what sensors detect blood osmolarity?

A

osmoreceptors in the kidney

24
Q

what condition must be met for concentrated urine to be formed?

A

if there is concentrated fluid in the extracellular space in the renal medulla

25
Q

what is the vasa recta?

A

capillary network which surrounds the loops of Henle juxtamedullary nephrons

26
Q

which is thinner - the descending or ascending loop of Henle?

A

Descending

27
Q

what channels are found in the descending loop of Henle?

A

aquaporins

28
Q

what happens to fluid as it goes down the descending loop of Henle?

A

gets more and more concentrated

29
Q

what is the ascending loop of Henle impermeable to?

A

water

30
Q

what mechanisms in the ascending loop of Henle causes ions to be pumped out into the ECF?

A

ROMK - renal outer medullary potassium channel
NKCC2 channels
Na+/K+ pump

31
Q

where is ROMK found?

A

in the epithelial cells lining the cells of the ascending loops

32
Q

what do ROMK do?

A

transport potassium out into the lumen, creating a positive voltage in the tubular lumen

33
Q

where are NKCC2 channels found?

A

in the luminal walls of epithelial cells of the ascending loop of Henle

34
Q

what does the NKCC2 channel do?

A

Pumps 1 sodium, 1 potassium and 2 chlorides into the ascending limb from the lumen

35
Q

how are sodium and chlorine moved into the ECF from the ascending limb?

A

sodium is actively pumped out by a Na+/K+ pump

chloride moves out passively with sodium

36
Q

how do loop diuretics work?

A

Block the transport of sodium and chloride out of the loop of Henle

37
Q

what type of drug is furosemide and how does it work?

A

loop diuretic
block the transport of sodium and chloride out of the loop of Henle by inhibiting NKCC2 channels –> ons aren’t pumped into the ascending limb wall and therefore can’t be pumped into the ISF –> conc urine cant be formed

38
Q

what is a risk of furosemide?

A

similar NKCC2 channel exists in the ear - too much furosemide can lead to irreversible hearing loss

39
Q

what are side effects of furosemide?

A

low BP with standing, ringing in the ears and sensitivity to the sun.

40
Q

what is the site of ADH action?

A

collecting duct

41
Q

what happens to urine in the absence of ADH?

A

no reabsorption of water

dilute urine

42
Q

what happens to urine in the presence of ADH?

A

reabsorption of water –> urine as concentrated as renal medullary fluid

43
Q

what happens to urea in the kidneys?

A

actively pumped out of collecting duct into the ISF –> increases solute conc of renal medulla –> more concentrated urine
some urine passes into the ascending limb
some is lost in the urine

44
Q

what is the countercurrent multiplier?

A

process of pumping salts into the extracellular fluid around the loop of Henle.

45
Q

what is the countercurrent exchange?

A

provided by vasa recta which maintains concentration gradient. These prevent the wash out of blood as it follows the tubule in osmolarity

46
Q

what is water diuresis and what does it lead to?

A

due to drinking too much water, blood becomes dilute. ADH release inhibited –> high volume of dilute urine –> called diabetes insipidus

47
Q

what is osmotic diuresis and what does it lead to?

A

excess glucose in the blood, glucose isn’t totally reabsorbed in the PCT. Some glucose through the collecting duct provides an osmotic force –> water pulled into the urine –> high volume sugary urine –> called diabetes mellitus

c (25 decks)

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