Endocrine and neuronal regulation of blood pressure

Question 1

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

Answer 1

Short term regulation

Long term regulation

Question 2

What controls short term regulation of blood pressure ?

Answer 2

Autonomic nervous system

Baroreflex

Question 3

What controls long term regulation of blood pressure?

Answer 3

Kidney

Question 4

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

Answer 4

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

Question 5

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

Answer 5

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

Question 6

How does the baroreflex control blood pressure?

Answer 6

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

Question 7

How does the vagus nerve adjust heart rate?

Answer 7

Decrease in vagal activity leads to an increase in heart rate

Question 8

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

Answer 8

Causes vasoconstriction of peripheral blood vessels

Question 9

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

Answer 9

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

Question 10

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

Answer 10

Affect sodium and water reabsorption

Question 11

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

Answer 11

Atrial natriuretic peptide

Renin-angiotensin system

ADH

Question 12

What organ synthesises ANP?

Answer 12

The heart

Question 13

What is the goal of ANP?

Answer 13

To decrease blood volume

Question 14

How does ANP control blood pressure?

Answer 14

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

Question 15

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

Answer 15

Inhibits the renin-angiotensin system

Inhibits renin secretion

Question 16

What part of the heart secretes ANP?

Answer 16

Cardiac atrial myocytes synthesise and store ANP

Question 17

What do ventricles produce?

Answer 17

BNP

Brain natriuretic peptide

First isolated in the brain

Question 18

Structure of ANP

Answer 18

28 aa peptide

17 aa ring in the middle of the molecule

Question 19

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

Answer 19

Increase blood pressure

Question 20

What is the sensor of the renin-angiotensin system?

Answer 20

The juxtaglomerular apparatus

Question 21

What does the juxtaglomerular apparatus control?

Answer 21

Blood pressure

Concentration of solutes in the plasma

Question 22

What is the juxtaglomerular apparatus made of?

Answer 22

Glomerulus

Macula densa cells

Granular renin producing cells

Afferent and efferent arterioles

Question 23

Which cells produce renin?

Answer 23

Granular renin producing cells

Question 24

What are granular renin producing cells sensitive to?

Answer 24

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

Question 25

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

Answer 25

Renin secretion is enhanced

Question 26

Describe the steps of renin-angiotensin system

Answer 26

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

Question 27

What are the effects of Angiotensin II?

Answer 27

Can affect smooth muscle receptors Causes release of Aldosterone from the adrenal gland When in high concentration, can activate the release of ADH

Question 28

What does Angiotensin II release when in high concentration?

Answer 28

ADH

Question 29

What is ADH?

Answer 29

A small peptide

Question 30

What is another name for ADH?

Answer 30

Vasopressin

Question 31

What are the two receptors for ADH?

Answer 31

V1 V2

Question 32

Where is the receptor V1 found?

Answer 32

In the vasculature

Question 33

What happens when ADH binds to V1?

Answer 33

G-protein coupled receptor Increases IP3+ and Ca2+ levels Causes vasoconstriction and release of von Willebrand factor/ factor VIII from endothelial cells

Question 34

What happens when ADH binds to V2?

Answer 34

G-protein coupled receptor Increases cAMP levels Causes insertion of aquaporin-2 channels into the luminal membrane of principal cells

Question 35

Which cells of the collecting duct does ADH affects?

Answer 35

Principal cells

Question 36

What types of receptors are V1 and V2?

Answer 36

G-protein coupled receptors

Question 37

What is normal plasma osmolarity?

Answer 37

280 - 330 mosm/L

Question 38

What releases ADH?

Answer 38

Posterior pituitary

Question 39

Which nucleus of the posterior pituitary releases ADH?

Answer 39

Suprachiasmatic nucleus

Question 40

What happens to the kidneys upon prolonged hypertension?

Answer 40

Kidney injury develops Leads to hypertensive nephropathy Damage to the capillaries leads to fibrosis

Question 41

What consequences does kindey injury have on blood volume regulation?

Answer 41

Kidney injury impairs blood volume regulation

Question 42

What causes benign arterial hypertension?

Answer 42

Excess sodium in the blood leads to activation of Angiotensin

Question 43

Pathogenesis of benign arterial hypertension

Answer 43

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

Question 44

What structural changes does benign arterial hypertension cause?

Answer 44

Tubular atrophy Interstitial fibrosis Glomerular alterations Periglomerular fibrosis