Short Term Control of BP

Question 1

What is the main influence on Bp short term?

Answer 1

The Baroreflex

Question 2

Describe the Baroreflex.

Answer 2

The Baroreflex involves baroreceptors which detect the stretching of blood vessels in response to changes in the MAP.

Question 3

What is MAP?

Answer 3

Mean Arterial Pressure

Question 4

What two factors affect MAP?

Answer 4

Cardiac Output and TPR

Question 5

Where are the Baroreceptors situated?

Answer 5

In the Aorta and the Common carotid arteries.

Question 6

What happens to the receptors when the vessels are stretched.

Answer 6

Stretching triggers an increase in frequency of Action Potentials and vice versa.

Question 7

Which nerves carry the sensory information from the Baroreceptors and where does it go?

Answer 7

The Vagus nerve and the Glossopharyneal nerve.

The impulses are sent to the Medulla.

Question 8

Which systems does the Medulla then trigger?

Answer 8

The Parasympathetic (via the vagus nerve) and the sympathetic system.

Question 9

Compare the effects of Venoconstriction to Arteriolar Constriction

Answer 9

Venoconstriction= squeezes blood out of the veins and into the heart therefore increasing EDV and stroke volume= higher MAP
Constriction of Arteries= increases resistance to flow so increases the TPR= HIgher MAP