L13: Arterial blood pressure and its regulation

Question 1

what are systolic and diastolic blood pressures?

Answer 1

systolic blood pressure is the highest pressure exerted on artery walls during systole of the heart

diastolic pressure is the lowest pressure exerted on the heart during diastole of the heart .

Question 2

what is pulse pressure ?

Answer 2

it is the difference between highest pressure and lowest pressure ( SBD-DBP)

Question 3

What is mean arterial blood pressure?

Answer 3

average pressure in aorta and its major branches ( nearest to diastolic blood pressure )

Question 4

what is a longer , the diastolic period or the systolic period ?

Answer 4

the period of diastole is twice as long as the period of systole

Question 5

what happens to ABP as the individual gets older ?

Answer 5

it increases as the vessels loose their elasticity

Question 6

what is the normal range of arterial blood pressure ?

Answer 6

100-140/60-90 mmHg

Question 7

what arterial blood pressure would indicate hypotension ?

Answer 7

<90/60

Question 8

what arterial blood pressure would indicate hyper tension ?

Answer 8

> 140/90

Question 9

how do you calculate arterial blood pressure ?

Answer 9

cardiac output X total peripheral resistance

Question 10

what is responsible for short term regulation of arterial blood pressure ? what does it affect ?

Answer 10

baroreceptors :rapidly acting hormones (neurohormones ), it affects the capacity

Question 11

what is responsible for long term arterial blood pressure regulation ?what do they affect ?

Answer 11

renal: slow acting hormones , they affect the blood volume

Question 12

explain the baroflex.

Answer 12

it is the short term response for high arterial blood pressure .

1. ) stimulus increases ABP , this is sensed by carotid sinus and aortic arch (receptors)
2. ) vagus nerve and glossopharengeal nerves then relay this message ( afferents )
3. )to cardio-inhibitory and vasomotor centers
4. ) these centers then activate a strong para sympathetic discharge to bring back the ABP back to normal

Question 13

what are the chemoreceptors that sense if the ABP is too low ?

Answer 13

carotid body and aortic body

Question 14

when is the chemoreceptor reflex activated ?

Answer 14

when ABP is less than 80

Question 15

what is the CNS ischemic response and when is it activated ?

Answer 15

it is a direct stimulation o the neurons of VMC that lead to strong sympathetic discharge leading to strong vast constriction . it is a last ditch effort .

Question 16

what are the rapid acting hormones responsible for short term regulation of arterial blood pressure?

Answer 16

renin
epinephrine and norepinephrine
vasopressin

Question 17

what are the actions of Angiotensisn II?

Answer 17

very strong vasoconstrictor

Question 18

explain the renal function in long term arterial blood pressure regulation ?

Answer 18

when ABP rises , urine volume increases , reducing the circulating blood volume , this results in decrease in venous return and cardiac output and the arterial blood pressure

Question 19

what are the slow acting hormones that play a role in long term arterial blood regulation ?

Answer 19

renin 
vasopressin 
aldosterone 
cortisol
atrial natretic peptide