Theme 3: Lecture 10 - Drug treatments for CVD 1 Flashcards Preview

Module 103: The Heart, Lungs and Blood > Theme 3: Lecture 10 - Drug treatments for CVD 1 > Flashcards

Flashcards in Theme 3: Lecture 10 - Drug treatments for CVD 1 Deck (20)
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1
Q

Definition of hypertension

A

Persistently higher than normal blood pressure

2
Q

How do guidelines say BP should by measured

A

Using ABPM (ambulatory blood pressure monitoring) or HBPM (home blood pressure monitoring)

3
Q

When is high BP treated

A

If the mean BP is above 150/95

4
Q

What is a normal BP

A

120/80

5
Q

BP equation

A

BP =CO x TPR (total peripheral resistance)

6
Q

Cardiac output equation

A

CO = stoke volume x HR

7
Q

What is stoke volume regulated by

A

The ventricles

8
Q

What is total peripheral a measure of

A

The degree of constriction of the arterioles

9
Q

How does the sympathetic NS increase cardiac output

A
  • It releases noradrenaline and adrenaline which act on alpha 1 receptors on smooth muscle cells causing arterioles to constrict, this leads to an increase in afterload and total peripheral resistance
  • Noradrenaline and adrenaline also act on beta 1 receptors on the SAN and ventricular muscle to increase heart rate and force of contraction respectively
  • It causes the venules to constrict by acting on alpha 1 receptors of the smooth muscle cells which causes an increase in preload which causes an increase in the force of contraction
10
Q

Which neurotransmitter does the parasympathetic nervous system mainly use

A

Acetyl choline

11
Q

Describe the biochemical pathway that enables the sympathetic nervous system to increase the force and rate of contraction of the heart

A
  • Sympathetic NS releases adrenaline and noradrenaline
  • These act on beta 1 receptors
  • Causing an increase in cAMP
  • Causing an increase in intracellular Ca2+
  • Causing an increase in the force and rate of contraction
12
Q

describe the biochemical pathway that allows the parasympathetic nervous system to decrease the frequency of the heart rate

A
  • Parasympathetic NS releases acetyl choline
  • This acts on muscarinic 2 (M2) receptors
  • Causing a decrease in cAMP
  • Causing a decrease in the frequency of the heart rate
13
Q

Describe the biochemical pathway that enables the sympathetic NS to cause vasoconstriction

A
  • SNS releases noradrenaline
  • This acts on alpha 1 receptors
  • This causes an increase in inositol triphosphate (IP3)
  • This causes an increase in Ca2+ influx into the cell and releases Ca2+ from the intracellular stores
  • This leads to vasoconstriction
14
Q

Describe the biochemical pathway that enables the sympathetic NS to cause relaxation of blood vessels

A
  • SNS releases adrenaline
  • This acts on beta 2 receptors
  • This causes an increase in cAMP
  • This leads to relaxation
15
Q

What does angiotensin II do

A
  • Causes an increase in sympathetic activity
  • Tubular absorption of Na+ and Cl-, as well as K+ excretion leading to water retention
  • Causes aldosterone secretion
  • Constriction of arterioles
  • The pituitary gland to release ADH
16
Q

How is BP regulated by RAAS

A
  • Decreased cardiac output causes reduced renal flow
  • This activates RAAS causing the release of angiotensin II and aldosterone
  • Aldosterone causes Na+ and water retention through AT1 receptors which causes an increase in preload causing an increase in BP
  • Angiotensin II causes veno constriction through AT1 receptors which causes an increase in preload causing an increase in BP
  • Angiotensin II also causes arterio constriction through AT1 receptors causing an increase in afterload which causes an increase in BP
17
Q

AT1 receptor

A
  • Angiotensin II type 1 receptor

- Involved in the RAAS pathway

18
Q

Describe the biochemical pathway that causes an increase in angiotensin II to cause constriction of blood vessels

A
  • Increase in angiotensin II
  • Acts on AT1 receptors
  • Leads to an increase in IP3 (inositol triphosphate)
  • Leads to and increase in intracellular Ca2+
  • Causes constriction of arterioles
19
Q

What does the choice of drug depend on

A
  • Age
  • Race
  • Co existing diseases
20
Q

How does aldosterone aid Na+ and water retention

A
  • Aldosterone activates cytoplasmic receptors which bind to the nucleus to increase expression of Na+ channels
  • ENaC (epithelial Na+ channels) sit in the membrane of distal convoluted tubule allowing Na+ to be reabsorbed
  • An increase in Na+ retention causes an increase in water retention

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