short term control of blood pressure

Question 1

what is responsible for short-term control of arterial blood pressure?

Answer 1

arterial baroreflex

Question 2

define baroreceptors:

Answer 2

they are stretch-sensitive mechanoreceptors located in the walls of the carotid arteries and aorta.

Question 3

state 2 types of baroreceptors, and describe how they send signals to the brain:

Answer 3

Aortic arch baroreceptors →Vagus nerve → Medullary cardiovascular centres

Carotid sinus baroreceptors → Glossopharyngeal nerve → Medullary cardiovascular centres

Ensures adequate blood flow to the brain and heart by maintaining sufficient mean arterial pressure.

Question 4

how does vasoconstriction increase blood pressure?

Answer 4

↓ venous radius = ↑ venous return = ↑ preload = ↑ EDV = ↑ strength of contraction

Question 5

how does arteriolar constriction increase blood pressure?

Answer 5

↓ arterial radius = ↑ resistance to flow = ↑ TPR = ↑ MAP

Question 6

define the Valsalva manoeuvre:

Answer 6

forced expiration against a closed glottis

used to assess the strengthof baroreflex

Question 7

give 2 good examples of arterial baroreflex in action:

Answer 7

changes in posture and the Valsalva manoeuvre

Question 8

results of low/ high MAP:

Answer 8

Too low MAP → fainting (syncope)

Too high MAP → hypertension