Urinary 3 - Control of Blood Pressure

Question 1

Which forces are named ‘Starling’s forces’?

Answer 1

1) Hydrostatic pressure

2) Oncotic pressure

Question 2

Define hydrostatic pressure:

Answer 2

The pressure exerted by a liquid

Question 3

Define oncotic pressure:

Answer 3

Osmotic pressure exerted by proteins in plasma

Question 4

What effect does oncotic pressure usually have on water in the body?

Answer 4

It tends to pull water into the circulatory system

Question 5

What effect does hydrostatic pressure tend to have on water in the body?

Answer 5

Pushes water out of the circulatory system

Question 6

What effect does the sympathetic NS have on the RAA-system?

Answer 6

Stimulates Renin release and the RAA-system

Question 7

Name 2 factors which stimulate the RAA-system:

Answer 7

1) Sympathetic NS (beta-1)

2) Decreased [NaCl] in Distal Tubule (Macula Densa)

Question 8

How does the Macula Densa respond if it detects decreased [NaCl] in the Distal Tubule?

Answer 8

Stimulates Juxtaglomerular cells to release:

• Renin (stimulates RAA-system)
• Prostaglandins (vasodilation of afferent arteriole)

Question 9

What cells release Renin?

Answer 9

Juxtaglomerular cells in the kidney

Question 10

What is the function of Renin?

Answer 10

Enzyme causes conversion of Angiotensinogen to Angiotensin I

Question 11

Where is Angiotensinogen released from?

Answer 11

Liver

Question 12

What enzyme converts Angiotensin I to Angiotensin II?

Answer 12

ACE = Angiotensin Converting Enzyme

Question 13

Where is Angiotensin Converting Enzyme released from?

Answer 13

Vascular endothelium

Question 14

Name the main proteins involved in the RAA-system:

Answer 14

• Renin
• Angiotensinogen
• Angiotensin I
• Angiotensin Converting Enzyme
• Angiotensin II

Question 15

What effect does Angiotensin II have on aldosterone release?

Answer 15

Increases aldosterone release

Question 16

What effect does Angiotensin II have on ADH release?

Answer 16

Increases ADH release

Question 17

What effect does Angiotensin have on the thirst response?

Answer 17

Increases thirst response

Question 18

What is the overall effect of the RAA-system on blood pressure?

Answer 18

Increases blood pressure

Question 19

How does Aldosterone increase blood pressure?

Answer 19

Causes increased numbers of ENaC in Collecting Ducts

Question 20

How does ADH increase blood pressure?

Answer 20

Increases insertion of AQP2 into apical membrane of Collecting duct principle cells.

Question 21

Name the 2 types of Natriuretic peptides:

Answer 21

1) Atrial Natriuretic Peptide (ANP)

2) Brain Natriuretic Peptide (BNP)

Question 22

Where are natriuretic peptides synthesised and stored?

Answer 22

Heart (Atrial myocytes)

Question 23

Name 4 factors which increase the secretion of natriuretic peptides into the circulation:

Answer 23

1) Increased sympathetic NS stimulation to heart
2) Cardiac distension
3) Increased Angiotensin II
4) Increased Endothelin

Question 24

What is the overall effect of Natriuretic peptides on blood pressure?

Answer 24

Decrease blood pressure

Question 25

What is the overall effect of increased sympathetic stimulation on blood pressure?

Answer 25

Increased blood pressure

Question 26

What are the 2 main effects Natriuretic peptides have on the kidneys?

Answer 26

1) Natriuresis (causes diuresis) | 2) Decreased Renin release (decreases RAA-system)

Question 27

How do Natriuretic peptides effect blood vessels?

Answer 27

Cause vaso- and veno-constriction

Question 28

Name the most sensitive serum biomarker of heart failure:

Answer 28

Brain Natriuretic Peptide (BNP)

Question 29

How do natriuretic peptides affect GFR?

Answer 29

Increase GFR (vasodilation of afferent arteriole to cause natriuresis and diuresis)

Question 30

How does heart failure affect ADH release?

Answer 30

Increases release of ADH

Question 31

Describe the production of Prostaglandins:

Answer 31

Arachidonic Acid is converted to Prostaglandin via Cyclo-oxygenase (COX)

Question 32

What effect do Prostaglandins have on the GFR?

Answer 32

Increase GFR as vasodilate afferent arterioles

Question 33

What reaction is catalysed by Cyclo-oxygenase?

Answer 33

Arachidonic Acid to Prostaglandins

Question 34

Name the potent vasodilator produced by endothelial cells:

Answer 34

Nitric Oxide

Question 35

Describe the production of Bradykinin:

Answer 35

Kininogen is converted to Bradykinin via Kallikrein

Question 36

How do ACE inhibitors cause a cough?

Answer 36

ACEi also inhibit the breakdown of Bradykinin, so the pro-inflammatory Bradykinin settles in lung tissue, causing cough.

Question 37

How do ACE inhibitors affect Bradykinin?

Answer 37

They inhibit the breakdown of Bradykinin into inactive metabollites.

Question 38

What effect does Dopamine have on renal blood vessels and GFR?

Answer 38

Vasodilation = increased GFR

Question 39

What effect does Dopamine have on renal reabsorption of NaCl?

Answer 39

Inhibits Na+/H+ exchanger and Na+/K+-ATPase in PCT and TAL | = Decreases NaCl reabsorption

Question 40

Name some causes of hypertension:

Answer 40

- Conn's syndrome - Cushings syndrome - Phaeochromocytoma - Renovascular disease - Renal parenchymal disease (95% unknown cause)

Question 41

Name some non-pharmacological treatments of Hypertension:

Answer 41

- Weight loss - Increase exercise levels - Decrease salt intake

Question 42

Name some Pharmacological treatments of Hypertension:

Answer 42

- Thiazides (diuretics) - ACE inhibitors - DHP Ca2+ channel blockers - alpha1 antagonists - Angiotensin II Receptor Blockers (ARBs)

Question 43

Define hypertension:

Answer 43

Sustained BP > 140/90 mmHg