Endocrine and neuronal regulation of blood pressure Flashcards Preview

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Flashcards in Endocrine and neuronal regulation of blood pressure Deck (44):
1

What are the two ways in which blood pressure is controlled?

Short term regulation

Long term regulation

2

What controls short term regulation of blood pressure ?

Autonomic nervous system

Baroreflex

3

What controls long term regulation of blood pressure?

Kidney

4

What is an example of something that triggers short term control of blood pressure ?

Postural hypotension - decrease in blood pressure due to gravity to head/neck

5

What is an example of something that triggers long term control of blood pressure?

Increase uptake of salt/ water fue to consumption of salty food

6

How does the baroreflex control blood pressure?

Baroreceptors detect changes in arterial pressure

Signal is sent to the medulla of the brainstem

Vagus nerve adjusts heart rate

Sympathetic nerves adjust cardiac contractility and peripheral resistance

7

How does the vagus nerve adjust heart rate?

Decrease in vagal activity leads to an increase in heart rate

8

How do the sympathetic nerves adjust cardiac contractility and peripheral resistance?

Causes vasoconstriction of peripheral blood vessels

9

How do the kidneys regulate long term control of blood pressure?

Hormones act on the kidney to regulate long term control of blood pressure

10

How do the hormones released that act on the kidney affect long term control of blood pressure?

Affect sodium and water reabsorption

11

What are the three hormones that act on the kidney that regulate long-term control of blood pressure?

Atrial natriuretic peptide

Renin-angiotensin system

ADH

12

What organ synthesises ANP?

The heart

13

What is the goal of ANP?

To decrease blood volume

14

How does ANP control blood pressure?

ANP binds to receptors on the DCT and collecting ducts

Interacts with NCC (sodium-chlorine cotransporter) and ENaC (epithelial sodium channel)

ANP also inhibits renin secretion - inhibits the renin-aldosterone system

15

What is the effect of ANP on the renin-angiotensin system?

Inhibits the renin-angiotensin system

Inhibits renin secretion

16

What part of the heart secretes ANP?

Cardiac atrial myocytes synthesise and store ANP

17

What do ventricles produce?

BNP

Brain natriuretic peptide

First isolated in the brain

18

Structure of ANP

28 aa peptide

17 aa ring in the middle of the molecule

19

What is the main goal of the renin-angiotensin system?

Increase blood pressure

20

What is the sensor of the renin-angiotensin system?

The juxtaglomerular apparatus

21

What does the juxtaglomerular apparatus control?

Blood pressure

Concentration of solutes in the plasma

22

What is the juxtaglomerular apparatus made of?

Glomerulus

Macula densa cells

Granular renin producing cells

Afferent and efferent arterioles

23

Which cells produce renin?

Granular renin producing cells

24

What are granular renin producing cells sensitive to?

Perfusion pressure - when P is low in afferent arteriole, it stimulates renin secretion

NaCl deliver to macula densa cells - when decreased, renin secretion is enhanced

25

What happens when delivery of NaCl to macula densa cells is decreased?

Renin secretion is enhanced

26

Describe the steps of renin-angiotensin system

1. Angiotensinogen is released from the liver

2. Renin is released from the kidneys, converts Angiotensinogen -> Angiotensin I

3. Angiotensin I is inactive

4. ACE releasedfrom the lungs and converts Angiotensin I -> II

27

What are the effects of Angiotensin II?

Can affect smooth muscle receptors

Causes release of Aldosterone from the adrenal gland

When in high concentration, can activate the release of ADH

28

What does Angiotensin II release when in high concentration?

ADH

29

What is ADH?

A small peptide

30

What is another name for ADH?

Vasopressin

31

What are the two receptors for ADH?

V1

V2

32

Where is the receptor V1 found?

In the vasculature

33

What happens when ADH binds to V1?

G-protein coupled receptor

Increases IP3+ and Ca2+ levels

Causes vasoconstriction and release of von Willebrand factor/ factor VIII from endothelial cells

34

What happens when ADH binds to V2?

G-protein coupled receptor

Increases cAMP levels

Causes insertion of aquaporin-2 channels into the luminal membrane of principal cells

35

Which cells of the collecting duct does ADH affects?

Principal cells

36

What types of receptors are V1 and V2?

G-protein coupled receptors

37

What is normal plasma osmolarity?

280 - 330 mosm/L

38

What releases ADH?

Posterior pituitary

39

Which nucleus of the posterior pituitary releases ADH?

Suprachiasmatic nucleus

40

What happens to the kidneys upon prolonged hypertension?

Kidney injury develops

Leads to hypertensive nephropathy

Damage to the capillaries leads to fibrosis

41

What consequences does kindey injury have on blood volume regulation?

Kidney injury impairs blood volume regulation

42

What causes benign arterial hypertension?

Excess sodium in the blood leads to activation of Angiotensin

43

Pathogenesis of benign arterial hypertension

Activation of angiotensin causes accumulation of hyaline in the wall of arterioles

Narrowing lumina and thickening walls leads to ischaemia

Tubular atrophy, interstitial fibrosis , glomerular alterations and periglomerular fibrosis

In advanced stages = renal failure

44

What structural changes does benign arterial hypertension cause?

Tubular atrophy

Interstitial fibrosis

Glomerular alterations

Periglomerular fibrosis