pressure and control of blood pressure

Question 1

what is the driving force for pushing blood through the circulation

Answer 1

mean arterial pressure

Question 2

what happens if MAP is too low

Answer 2

fainting

Question 3

what reflex controls blood pressure

Answer 3

arterial baroreflex

Question 4

if pressure is too low what series of events occur

Answer 4

signals from the aortic aortic arch baroreceptors are carried by the vagus nerve to the MCC and cause a sympathetic response (increase heart rate)

Question 5

if pressure is too high what series of events will occur

Answer 5

signals from the carotid sinus baroreceptors are carried by the glossopharyngeal verve to the MCC and cause a decrease in heart rate

Question 6

what are five other inputs to the medullary cardiovascular center

Answer 6

cardiopulmonary baroreceptors (central blood volume), central chemo receptors (arterial CO2 and O2), chemo receptors in the muscles (metabolite concentration), joint receptors (joint movement) and higher centers (hypothalamus and cerebral cortex)

Question 7

what is first phase in the valsava maneuver

Answer 7

is increased thoracic pressure is transmitted through to the aorta (big jump in blood pressure)

Question 8

what is the second phase in the valsava maneuver

Answer 8

the increased thoracic pressure reduces the filling pressure from the veins which reduces VR, EDV, SV, CO, MAP. The reduced MAP is detected by the baroreceptors which initiate a reflex increase in CO and TPR (adrenaline is also produced)

Question 9

what is the third phase in the valsava maneuver

Answer 9

manoeuvre the decrease in thoracic pressure is transmitted through the aorta hence the drop in blood pressure
Venous return is then restored so stroke volume increases but reflex effects have not worn off

Question 10

what is the valsava maneuver used to test

Answer 10

autonomic function

Question 11

what is the valsava maneuver used to treat

Answer 11

super ventricular cardiomyopathy