Short Term Control Of Blood Pressure

Question 1

What is the main driving force pushing blood through the circulation?

Answer 1

MAP

Question 2

Where are the baroreceptors located?

Answer 2

In the aortic arch and carotid sinus

Question 3

What nerves are the carotid sinus and aortic arch innervated by?

Answer 3

Carotid sinus - glossopharyngeal nerve

Aortic arch - vagus nerve

Question 4

What stimulates the barorecptors?

Answer 4

They respond to the strecth therefore an increase in MAP

Question 5

What is the normal resting value of MAP of the baroreceptor firing rate?

Answer 5

80mmHg

Normal MAP is between 70-105

Question 6

Where do the baroreceptors synapse?

Answer 6

The medullary cardiovascular center

Question 7

What does the activation of the sympathetic fibres from the cardiovascular center result in?

Answer 7

Noradrenaline released from sympathetic fibres
Bind to b1 receptors in the sino atrial node causing increase in HR
Bind to A1 recepors in vessels causing arteriolar constriction and venoconstriction
Bind to B1 receptors in the myocardium causing an increase in contractility of the ventricles. It does this by increasing the release of calcium therefore increasing strength of contraction