RAAS

Question 1

What does RAAS regulate ?

Answer 1

Blood volume

Systemic vascular resistance

Question 2

What kind of hormones are renin, angiotensin II and aldosterone?

Answer 2

Renin - enzymatic hormone
Angiotensin II - peptide hormone
Aldosterone - steroid hormone

Question 3

What leads to a decrease in blood volume ?

Answer 3

1. Dehydration
2. Na+ deficiency
3. Haemorrhage
4. Hypovolaemia

Question 4

What secretes renin?

Answer 4

Juxtaglomerular cells

Question 5

Where are juxtaglomerular cells located ?

Answer 5

Afferent arterioles in the kidneys

Question 6

What is the function of the kidneys ?

Answer 6

To filter the blood

Question 7

What is the name of the functional unit of the kidney?

Answer 7

Nephron

Question 8

What is the filtering component of the nephron .

Answer 8

Glomerulus

Question 9

Where do fluids or solutes that are filtered from the blood enter ?

Answer 9

Proximal tubule

Question 10

How is blood brought to the blood?

Answer 10

Afforestation arteriole

Question 11

What type of cells are juxtaglomerular cells?

Answer 11

Specialised smooth muscle cells

Question 12

How is a decrease in perfusion pressure detected ?

Answer 12

By baroreceptors

Question 13

What detects a decrease in Na+ and where is this detected ?

Answer 13

Macula dense cells in the DCT

Question 14

What type of cells are macula dense cells?

Answer 14

Specialised epithelial cells

Question 15

What is there present on the juxtaglomerular cells that respond to noradrenaline?

Answer 15

B1- adrenergic receptor

Question 16

What causes renin to be secreted ?

Answer 16

1. Drop in blood volume
2. Drop in Na+
3. Sympathetic stimulation

Question 17

What produces angiotensinogen ?

Answer 17

Plasma protein released by the liver

Question 18

What does ACE do?

Answer 18

It converts Ang I to Ang II

Question 19

Where is ACE usually found?

Answer 19

Endothelial lining of the vasculature of the lungs

Question 20

Where does Ang II travel to and what does this stimulate ?

Answer 20

The adrenal cortex

Aldosterone secretion

Question 21

Where does aldosterone travel and what does it do?

Answer 21

To the kidneys
Increases reabsorption of sodium and water
Increases secretion of K+ and H+ in urine

Question 22

What does the increase in Na+ and water reabsorption cause?

Answer 22

Increased blood volume causing Bp to return to normal

Question 23

What does Ang II cause in arterioles? What does this cause ?

Answer 23

Vasoconstriction

Raises peripheral resistance and blood pressure

Question 24

What can Ang II do?

Answer 24

1. Cause arteriole vasoconstriction by binding to AT1 receptor
2. Acts on hypothalamus to increase secretion of ADH
3. Stimulate sympathetic response to increase secretion of noradrenaline
4. Increase aldosterone secretion
5. Increase Na+/water reabsorption in PCT/vasoconstriction of renal arterioles

Question 25

Where are AT1 receptors found?

Answer 25

Vascular smooth muscle cells Brain Kidney Adrenal cortex

Question 26

What type of receptors are AT1 receptors?

Answer 26

G-protein linked receptors that are linked to PL-C in vsmc which leads to increase in Ca++

Question 27

Where are AT2 receptors found?

Answer 27

Fetus | Brain

Question 28

What will activation of AT2 receptor do?

Answer 28

1. Antagonise growth effects 2. Opens K+ channels 3. Increase NO production

Question 29

What type of receptors are AT2 receptors?

Answer 29

G-protein linked to various phosphatases

Question 30

Ang I receptors cause ______ | Ang II receptors cause ______

Answer 30

Vasoconstriction | Vasodilation

Question 31

What do AngII receptor activation cause to decrease ?

Answer 31

- VSMC proliferation - inflammation - oxidative stress - fibrosis - atherosclerosis - vascular remodelling - ischaemic brain damage - insulin resistance (Same as inhibiting AT1 receptors)

Question 32

What can overactivity of RAAS system cause which would result in hypertension ?

Answer 32

1. Renin-secreting tumour (RARE) 2. Increase angiotensinogen production 3. Renal artery stenosis

Question 33

List ways you could have increased angiotensinogen production.

Answer 33

1. Side effect of taking Steroid medication 2. Excessive cortisol production 3. Increase oestrogen levels (oral contraceptive pills) 4. During pregnancy

Question 34

What can suppress RAAS activity ?

Answer 34

1. Inhibitors of prostaglandin synthesis (reduces secretion of renin) 2. Beta adrenergic blockers 3. Renin inhibitors 4. ACE Inhibitors 5. AT receptors antagonists or blockers

Question 35

How do the macula dense cells communicate to the juxtaglomerular cells?

Answer 35

Through the production of prostaglandins

Question 36

Give an example of inhibitors for prostaglandin synthesis

Answer 36

Indomethacin

Question 37

Give an example of B-adrenergic blockers

Answer 37

Propranolol

Question 38

Give an example of renin inhibitors

Answer 38

Pepstatin | Enalkiren

Question 39

Give an example of ACE inhibitors

Answer 39

Captopril | Enalapril

Question 40

Give an example of AT receptor antagonists or blockers

Answer 40

Losarton

Question 41

What do ACE inhibitors do to bradykinin?

Answer 41

They decrease the degradation of bradykinin