Long-term Control of Blood Pressure Flashcards Preview

Cardiovascular > Long-term Control of Blood Pressure > Flashcards

Flashcards in Long-term Control of Blood Pressure Deck (20)
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1
Q

What is key in regulating mean arterial pressure?

A

Controlling plasma volume

2
Q

What are the functions of the kidneys?

A
Excretion of waste products 
Maintenance of ion balance
Regulation of pH 
Regulation of osmolarity 
Regulation of plasma volume
3
Q

In the kidney how is a very high osmolarity created outside the collecting duct?

A

By the renal counter-current system

4
Q

What determines the osmotic gradient?

A

Control over sodium ion transport

5
Q

What determines if water follows the osmotic gradient?

A

Control over the permeability of the collecting duct

6
Q

How is plasma volume conserved?

A

By making the collecting duct very permeable resulting in a lot of water reabsorption

7
Q

How is plasma volume reduced?

A

By making the collecting duct very impermeable resulting in little reabsorption of water

8
Q

What are the 3 hormone systems that regulate the process of plasma volume regulation?

A

Renin-angiotensin-aldosterone system
Antidiuretic hormone
Atrial natriuretic factor and brain natriuretic factor

9
Q

Where is renin produced?

A

From the juxtaglomerular of the kidney

10
Q

What triggers renin production?

A

Activation of sympathetic nerves to the juxtaglomerular apparatus
Decreased distension of afferent arterioles (the “renal baroreflex”)
Decreased delivery of Na+/Cl- through the tubule

11
Q

What does release of renin indicate?

A

Low mean arterial pressure

12
Q

What does renin do?

A

Converts inactive angiotensinogen to angiotensin I, which is turned into angiotensin II by angiotensin converting enzyme

13
Q

What does angiotensin II do?

A

Stimulates release of aldosterone from the adrenal cortex
Increases release of antidiuretic hormone (ADH) from the pituitary
Is a vasoconstrictor

14
Q

What is the total effect of angiotensin II on the body?

A

Increases mean arterial pressure

15
Q

Where is ADH produced?

A

Synthesised in the hypothalamus and released from the posterior pituitary gland

16
Q

What does ADH do?

A

Increases permeability of the collecting duct to water so reduces diuresis and increases plasma volume
Causes vasoconstriction

17
Q

Where is atrial natriuretic peptide (ANP) produced?

A

Produced in, and released from myocardial cells in the atria

18
Q

What triggers ANP release?

A

Increased distension of the atrium

19
Q

What is increased distension of the atrium a sign of?

A

Increased mean arterial pressure

20
Q

What does ANP do?

A

Increases excretion of sodium ions
Inhibits release of renin
Acts on medullary cardiovascular centres to reduce MAP