control of blood pressure

Question 1

what must arterial BP be maintained at?

Answer 1

120/80

Question 2

what are the 4 main control systems involved in controlling BP?

Answer 2

. arterial BP
. CO
. local circulation & blood
. extracellular fluid volume

Question 3

what are baroreceptors?

Answer 3

sensors located in blood vessels that sense BP and relay the info to the brain to maintain proper BP

Question 4

clusters of arterial baroreceptors are found in 2 locations, what are these?

Answer 4

aortic arch and carotid sinus

Question 5

which nerve carries information from the carotid sinus baroreceptor?

Answer 5

hering branch of glossopharyngeal

Question 6

which nerve carries information from the aortic arch baroreceptor?

Answer 6

vagus

Question 7

what do baroreceptors respond to?

Answer 7

stretching (pressure change)

Question 8

which baroreceptor is more sensitive and therefore more important?

Answer 8

carotid sinus

Question 9

which part of the brain receives inputs from baroreceptors?

Answer 9

nucleus tractus solitari

Question 10

when are baroreceptors active?

Answer 10

when blood pressure rises

Question 11

describe the series of events that follow a drop in BP?

Answer 11

. NTS activates B1 receptors which inhibit vagal nucleus and stimulate bulbar circulatory centre
. inhibition of vagal nucleus leads to reduced ACh acting on M2 receptors, increasing CO
. activation of bulbar circulator centres increases NA which activates a1 receptors on arteries increasing peripheral resistance
. Increase in NA also acts on b1 in heart, increasing CO

Question 12

describe the series of events that follow a rise in BP?

Answer 12

NTS activates a2 receptors which activate vagal nucleus and inhibit bulbar circulatory centre
. activation of vagal nucleus leads to increased ACh acting on M2 receptors, decreasing CO
. inhibition of bulbar circulator centres decreases NA which reduces activation of a1 receptors on arteries decreasing peripheral resistance
. decrease in NA also acts on b1 in heart, decreasing CO

Question 13

what does a clonidine a2 agonist do and what is a problem associated with it?

Answer 13

reduce BP but causes rebound hypertension

Question 14

what does a-methylopa do?

Answer 14

reduce hypertension in pregnant women

Question 15

what does nicorandil do?

Answer 15

treat angina

Question 16

how does the sympathetic NS constrict arteriolar radius?

Answer 16

produces NA which acts on a1 to constrict

Question 17

how do sympathetic cholinergic nerve dilate arteries?

Answer 17

produce ACH which acts on muscarinic receptors

Question 18

how does adrenaline dilate arteries?

Answer 18

acts on b2 receptors

Question 19

what is capillary shift?

Answer 19

the movement of fluid across the capillary membrane between the blood and the interstitial fluid compartment.

Question 20

at which point of the day is BP greatest?

Answer 20

waking

Question 21

at which point of the day is BP lowest?

Answer 21

sleeping

Question 22

give an example of something that increases BP?

Answer 22

exercise

Question 23

what effect does ageing have on BP?

Answer 23

increases

Question 24

what is hypertension?

Answer 24

hight BP

Question 25

give examples of secondary hypertension causes

Answer 25

. renal hypertension
. phaeochromocytoma
. aortic coarctation
. drug induced

Question 26

give examples of secondary hypertension causes

Answer 26

. salt intake
. cigarettes
. genetic predisposition
. stress

Question 27

what damage may hypertension cause to the CVS?

Answer 27

. thickening of arteries
. deterioration in atherosclerosis
. aneurysms in central arteries
. left ventricular hypertrophy

Question 28

what CVS diseases can hypertension lead to?

Answer 28

. malignant hypertension
. stroke
. renal disease
. cardiac hypertrophy
. cardiac ischaemia and angina

Question 29

what treatments are used to treat hypertension?

Answer 29

beta-adrenoreceptor antagonists, Ca channel blockers, alpha blockers, ACE inhibitors, diuretics, clonidine, methyl-dopa