Kidney 2 Flashcards Preview

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Flashcards in Kidney 2 Deck (37)
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1
Q

This artery branches off the abdominal aorta

A

Renal artery

2
Q

What does the renal artery do?

A

Brings unfiltered blood into the kidneys

3
Q

Interlobar arteries: path

A

Travel down renal columns and between pyramids

4
Q

Arcuate arteries: path

A

Arch over pyramids in cortical medullary junction

5
Q

Interlobular arteries connect to

A

Afferent arteriole

6
Q

Afferent arteriole branches off

A

Renal artery

7
Q

Afferent arteriole controls

A

Blood flow into the glomerulus

8
Q

Glomerular capillaries

A
  • fist-like structure

- forms filter

9
Q

Efferent arteriole

A

Carries blood minus filtrate out of glomerulus

10
Q

Peritubular capillaries

A
  • surround tubules and loop of Henle

- involved in reabsorption and secretion

11
Q

Vasa recta

A

part of peritubular system responsible for concentrating urine and blood supply to kidneys

12
Q

Renal vein delivers filtered and reabsorbed blood to

A

Inferior vena cava

13
Q

Renal blood flow per minute

A

1000-1200 mL, or 20-25% cardiac output per minute

14
Q

GFR =

A

Glomerular filtration rate

Rate of filtration and cleansing of blood

15
Q

GFR is related to _____ and _____, and is controlled by these types of actions

A
  • blood flow
  • blood pressure
  • neural/hormonal
16
Q

Renal blood flow: auto-regulation

Arterial BP

A

80-100 mmHg

17
Q

Renal blood flow: auto-regulation

These cells sense Na+ filtration

A

Macula densa

18
Q

Renal blood flow: auto-regulation

What about this controls GFR?

A

Constriction or dilation of afferent arteriole

19
Q

ANS regulation of RBF (renal blood flow)

Sympathetic

A

Sympathetic stimulation reflexively causes VASOCONSTRICTION of afferent arteriole

20
Q

Reflexive vasoconstriction of renal arterioles: how does this affect GFR and RBF?

A

GFR and RBF are decreased

21
Q

How does decreased RBF promote an increase in systemic pressure?

A

Decreased RBF

» decreased Na+ and water secretion

»» increased blood volume

»»» increased systemic pressure

22
Q

This system is a large regulator of renal blood flow (And therefore, BP)

A

Renin-angiotensin-aldosterone system (RAAS)

23
Q

Renin =

A

Enzyme formed and stored in cells of the juxtaglomerular apparatus

24
Q

What causes renin to be released with the goal of increasing BP?

A
  • Low BP sensed intrinsically by cells
  • Sympathetic NS component (receptors located on cells)
  • Macula densa cells sense low pressure in glomerulus (decreased Na+)
25
Q

The effects of the RAAS combine with those of _____ to regulate blood volume

A

ADH

26
Q

When is ADH release signaled?

A
  • decreased BP or BV signals hypothalamus

- hypothalamus signals posterior pituitary to release ADH

27
Q

What happens to water when ADH is released?

A

Reabsorbed into blood vessels from

  • distal tubules
  • collecting ducts
28
Q

How does the RAAS impact BP?

A

RAAS RAISES BP!

29
Q

Describe the RAAS

A
  1. Renin causes liver hepatocytes to release angiotensinogen
  2. ACE converts angiotensinogen to angiotensin I
  3. Angiotensin I » Angiotensin II
  4. Angiotensin II » Aldosterone
30
Q

What else affects renal blood flow?

A

Effects of

  • exercise
  • hypoxia
  • increased BP
31
Q

Renal blood flow: effects of exercise

A
  • sodium and water loss
  • relative decrease in BV and loss of Na+ (sweating)
  • increased BP
32
Q

Renal blood flow: effects of hypoxia

A
  • sympathetic response

- decrease in RBF

33
Q

Renal blood flow: effects of increased BP

A
  • renin and ADH decreased

- afferent arteriole dilated to increase filtration

34
Q

The nephron filters blood/plasma to:

A
  • reabsorb water, electrolytes, glucose, proteins within tubular system and capillaries
  • maintain fluid volume, electrolyte balance, pH
35
Q

GFR in a day

A

180L per day

36
Q

GFR: how much urine produced per day?

A

1-2 L per day

37
Q

How much water is reabsorbed by glomerular filtration?

A

99%