Short Term Control of Blood Pressure

Question 1

What is the equation used to calculate MAP?

Answer 1

MAP = CO x TPR

Question 2

What is mean arterial pressure?

Answer 2

The driving force pushing blood through the circulation

Question 3

What would low MAP cause?

Answer 3

Fainting

Question 4

What would high MAP cause?

Answer 4

Hypertension

Question 5

What does the arterial baroreflex minimise?

Answer 5

Fluctuations in the MAP

Question 6

What kind of nerve endings are baroreceptors?

Answer 6

Afferent

Question 7

What effect will decreased blood pressure have on baroreflex activation?

Answer 7

Baroreflex activation will decrease

Question 8

Where are baroreceptors located?

Answer 8

Aortic arch and carotid sinus

Question 9

Through what nerves do the baroreceptors send signals to the medullary cardiovascular centres?

Answer 9

Vagus and Glossopharyngeal nerves

Question 10

Through what nervous system does the response to the signals sent by the baroreceptors travel from the medullary cardiovascular centres to the heart?

Answer 10

Autonomic nervous system

Question 11

Will venoconstriction and arteriolar constriction be caused by high or low pressure?

Answer 11

Low pressure

Question 12

Give 3 other inputs to the medullary cardiovascular centres

Answer 12

• cardiopulmonary baroreceptors
• central chemoreceptors
• chemoreceptors in muscle
• joint receptors
• higher centres

Question 13

Can arterial baroreceptors regulate blood pressure in the long term?

Answer 13

No

Question 14

What does the long term control of blood pressure depend on?

Answer 14

Blood volume

Question 15

What effect does standing have on hydrostatic pressure?

Answer 15

Standing increases hydrostatic pressure

Question 16

What does increased hydrostatic pressure cause in the feet/legs?

Answer 16

Pooling of blood in veins/venules of the feet/legs

Question 17

What effect does standing have on baroreceptor firing rate?

Answer 17

Decreases baroreceptor firing rate

Question 18

What effect does the reflex response have on vagal tone?

Answer 18

Decreases vagal tone

Question 19

In the reflex response, what increases with decreasing vagal tone?

Answer 19

Heart rate

Cardiac output

Question 20

Give 3 factors that increase with increased sympathetic tone

Answer 20

• contractility
• venoconstriction
• arteriolar constriction

Question 21

What effect is there on thoracic pressure in the Valsalva manoeuvre?

Answer 21

Thoracic pressure increases

Question 22

What receptors detect the decrease in MAP in the Valsalva manoeuvre?

Answer 22

Baroreceptors

Question 23

In the Valsalva manoeuvre, the decrease in thoracic pressure is transmitted through to the

Answer 23

aorta

Question 24

In the Valsalva manoeuvre, decreased MAP is detected by baroreceptors which initiate reflex causing increased

Answer 24

cardiac output and TPR

Question 25

What is the Valsalva manoeuvre?

Answer 25

Forced expiration against a closed glottis