Brainscape's Knowledge GenomeTM

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


See full index

Physiology Block 7 > Filtration And Renal Blood Flow > Flashcards

Filtration And Renal Blood Flow Flashcards

1
Q

Where does filtration occur

A

Glomerulus only

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

What is the glomerulus

A
  • Capillary bed with two arterioles
  • afferent brings blood, efferent removes blood
  • efferent supply peritubualr capillary with renal blood flow (RBF)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is at the beginning of the PCT where filtrate enters after the glomerulus

A

Bowmans capsule

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

What forms the filtration membrane

A

Capillary endothelial cells, basement membrane and podocytes

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

How is rate of filtration measured

A

By glomerular rate

-GFR-clearance of inulin or creatinine

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

What is the best watt to determine GFR

A

By clearance of a molecule that is only filtered such a inulin or creatinine

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

What’s the quickest way to measure GFR

A

Blood creatinine levels.

-it takes a big change in GFR to change the creatinine levels in blood

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

Decreased GFR does what to creatinine

A

Increases

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

What gets filtered

A
  • water, small solutes
  • in proportion to their free plasma concentration
  • tubular fluid is same as plasma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What doesn’t filter

A
  • plasma proteins (mostly)

- small solutes bound to plasma proteins

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

Amount of solute that enters the tubular fluid

A

Filtered load

GFR*[Xa]
Usually reported as mg/min

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

What do we use filtered load to determine

A

How a solute is handled in the nephron because filtration and secretion adds solutes to the tubular fluid while secretion removes them we can say that

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

Filtered load + secretion =

A

Excretion

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

If secretion > filtered load then

A

(Net) secretion had to occur

-reabsorption COULD have occurred, just more secretion

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

If excretion < filtered load then

A

Net reabsorption had to occur

-secretion could have occurred, just more reabsorption

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

If excretion = filtered load

A

Then there was no net transport

Reabsorption and secretion could have occurred, just balanced

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

What are the forces that effect filtration

A

The same things that regulate filtration in other cap beds (pressure and osmolarity pressure)

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

Pressure in glomerulus

A

High because of two arterioles

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

Where is there low hydrostatic tissue pressure

A

Bowmans space, usually no osmotic pressure here

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is filtration heavily favored

A

Because of P(GC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why can we easily alter P(GC)

A

Because there are two arterioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the primary way of controlling GFR and RBF?

A

Altering P(GC) with the two arterioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Kf in kidneys

A

Huge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Effect on GFR if you increase P(GC)

A

Hypertension (increased GFR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Effect on GFR if you decreases P(GC)

A

Decrease (hypotension)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Effect on GFR if you increase osmotic (GC)

A

Decrease (dehydration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Effect on GFR if you decrease osmotic GC

A

Increase (liver failure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Effect on GFR if you increase P(BS)

A

Decrease (ureter blockage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Effect on GFR if you decrease P(BS)

A

Increase (hard to do this, its already low)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Effect on GFR if you increase osmotic (BS)

A

Increase (damage filtration membrane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Effect on GFR if you decrease osmotic (BS)

A

Decrease (hard to do, its already low)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Effect on GFR if you increase KF

A

Increase (damage filtration membrane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Effect on GFR if you decrease KF

A

Decrease (fibrosis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How many arterioles does the glomerulus have

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does changing either of the arterioles do

A

Affects GFR and renal blood flow

36
Q

Small changes in P(GC) result in what

A

LARGE changes in GFR, bc Kf is so large

37
Q

Changes in afferent diamter alter GFR and RBF how

A

In the same way.

  • constrict afferent-reduce both
  • dilate afferent-increase both
38
Q

Changes in efferent affect GFR and RBF how

A

In opposite ways

  • constrict-increase PGC and GFR but reduce RBF
  • dilate efferent-reduce PGC and GFR but increase RBF
39
Q

Dilating the afferent arteriole would have what affect on GFR and RBF

A

Increase both

40
Q

If a patients filtered load of K+ is 10mg/min and excretion rate is 1mg/min, how is K handled in the nephron

A

It is filtered, reabsorped, secreted,

41
Q

What is renal blood flow calculated by

A

PAH clearance

42
Q

Blood supply of the nephrons

A

Each nephron has its own blood supply, and is VERY close to a peritubular capillary to allow for transport

43
Q

What does the closeness of the nephron to the peritubular capillary ensure

A

Proper movement of solutes into and out of urine. Tight regulation is required

44
Q

What kind of flow does the vasa recta need to have

A

Low

45
Q

What kind of blood flow does kidneys have

A

High

46
Q

Kidney and control of blood flow

A

The kidney is able to control its own blood flow in response to change in pressure

47
Q

What kind of mechanism does the kidney use to regulate its own blood flow

A

Autoregulation

48
Q

How constant is the renal blood flow

A

Flow remains constant over 100mmHg + change in pressure

49
Q

What does increase in MAP do to GFR, renal blood flow, and urine output

A

Renal blood flow and GFR may be relatively constant, but as pressure increases there is an increase in urine flow

50
Q

What are the mechanisms of autoregulation that the kidney uses

A
  • myogenic response
  • tubuglomelur feedback
  • RAAS system
51
Q

Myogenic response of the kidney to regulate blood flow

A
  • response of smooth muscle to stretch
  • stretch a smooth muscle and it will actively contract against that force
  • maintains constant flow by changing resistance
52
Q

How does the myogenic response in the kidneys maintain constant flow

A

By changing resistance

53
Q

If you increase the transmural presure in a vessel, what happens

A

The diameter of the vessel gets smaller

54
Q

How does the tubuglomerular feedback work for regulation of renal blood flow

A

Nephron is able to sense GFR and regulate RBF to maintain it by alteration in diameter of afferent and/or efferent arterioles

55
Q

In the tubuglomerular feedback, what is linked with GFR and blood pressure?

A

Tubular sodium concentration

-high GFR=high tubular Na+

56
Q

Where does the tubuglomerular feedback occur

A

At the juxtaglomerular apparatus (JGA)

  • macula densa
  • juxtaglomerular cells
57
Q

In the tubuglomerular feedback, what happens if GFR is high

A

More NaCl will be filtered and will be taken up by macula densa

58
Q

What does more sodium in the tubular fluid do

A

Increases the activity of Na/K ATPase, which means more production of adenosine (Na levels low inside of cells because of the ATPase)

59
Q

What does build of adenosine do

A

Binds to smooth muscle cells and causes constriction of AFFERENT arterioles, reducing GFR and RBF

Also lowers renin production, so you get less AngII, which lowers pressure and GFR

60
Q

What happens if there is not enough NaCl

A

Dilates afferent and increases renin secretion

61
Q

All the things about increased GFR

A
  • increases Na flow
  • increased macula densa Na+ transport
  • increased adenosine release from macula densa
  • adenosine binds to A1 receptor
  • A1 receptor opens Ca channels in afferent
  • afferent constricts
  • P(GC) goes down
  • GFR goes back down towards normal
62
Q

All the things about not enough GFR

A
  • decrease flow of Na
  • decrease macula densa Na+ transport
  • decrease adenosine released from macula densa
  • less adenosine binds to A1 receptors
  • fewer A1 receptors opened Ca2+ channels in afferent arterioles
  • afferent dilates
  • P(GC) increases
  • GFR increases
63
Q

When is renin released from JGA

A
  • arterial pressure is low
  • tubular sodium decreases
  • effective circulating volume (ECV) decreases
64
Q

What is EVC (effective circulating volume)

A

How well tissues are being perfumed

65
Q

Does the GFR need to be high or low for renin to be released

A

Low

66
Q

What does release of renin eventually do

A

Increases AngII and aldosterone levels

67
Q

What do low levels of AngII do

A

Preferentially constricts efferent arterioles and increases GFR

68
Q

What do high levels of AngII do

A

Constrict afferent AND efferents. This can be damaging

69
Q

What does aldosterone do

A

Increases Na and water retention, which increases blood volume

70
Q

In which arterioles would the myogenic response autoregulatory response be most prominent

A

Afferent

71
Q

Myogenic and macula densa work mostly on the _____ arterioles

A

Afferent

72
Q

ANgII acts preferentially on _______ arterioles

A

Efferent

73
Q

Effect of afferent and efferent constriction and dilation on RBF and GFR

A

They have the same effect on RBF and opposite effects on GFR

74
Q

What is the kidney richly innervated by

A

SNS

75
Q

When does the SNS constrict the afferent AND efferent arterioles?

A

Only in times of high SNS stimulation (massive hemorrhage)

76
Q

What does norepinephrine and epinephrine do to kidney

A

Only used in extreme situations, will shut kidney down to preserve the heart and brain

77
Q

Nitric oxide action on the arterioles

A

Vasodilators, counteracts AngII’s effect on the AFFERENT

78
Q

Prostaglandins effects on arterioles of kidneys

A

Vasodilators, counteract AngIIs effect on AFFERENTS

79
Q

What are prostaglandins upregulated by

A

AngII and NE production to maintain GFR and RBF

80
Q

NSAIDS and prostaglandin in the kidneys

A

NSAIDS 9any COX inhibitors) will block production, could lead to kidney ischemia in already hypotensive patients

81
Q

Why should you not give someone NSAIDS if they are hypotensive

A

NSAIDS will block production of prostaglandins, could lead to kidney ischemia

82
Q

Kidney response to hemorrhage

A
  • decrease MAP, CO, preload, RBF, GFR
  • cant get a lot of blood to kidney, decreased Na+
  • myogenic response dilates afferent
  • JGA decreases adenosine, dilates afferent, decreases Ang, increases renin
  • increased renin causes constriction, AngII, increased TPR, constricted efferent, and increased MAP
83
Q

Kidneys response to massive MI

A

Decreased CO, MAP, profusion, RBF, GFR

Sets off chain, look it up

84
Q

Response to high dose of ACE-I

A

Less ANgII, decreases constriction of efferent, decrease TPR

85
Q

Low ECF

A

Increase in total blood volume

Physiology Block 7 (10 decks)

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