physiology 4 - long/short term control of BP

Question 1

what happens if MAP is too high

Answer 1

hypertension

Question 2

what happens if MAP is too low

Answer 2

Syncope

Question 3

what are two types of arterial baroreflex

Answer 3

aortic arch baroreceptors

carotid sinus baroreceptors

Question 4

where to the baroreceptors go to

Answer 4

the brain

Question 5

what signals do arterial baroreceptors send to the brain - why is this important

Answer 5

there is a normal firing rate 
any slower (less) = lower BP
any faster (more) = elevated

Question 6

what nerve passes information from the carotid sinus baroreceptors

Answer 6

the glossopharyngeal nerve

Question 7

what are the inputs to the medullary cardiovascular centres

Answer 7

Cardiopulmonary baroreceptors

Central
chemoreceptors

Chemoreceptors in muscle

Joint receptors

Higher centres

Question 8

what does Regulation of blood pressure

in the long term revolve around

Answer 8

Revolves around blood volume

Question 9

what controls long term blood pressure - what effects

Answer 9

the main sensors are the cardio-pulmonary baroreceptors

effects tend to be hormonal

Question 10

what does the long term regulation of blood pressure act on

Answer 10

the blood vessels and kidneys

Question 11

what are the two types of posture effecting blood pressure

Answer 11

effect of standing

the reflex tone

Question 12

what does the vasopressin do

Answer 12

increase water permeability of the collecting duct - increasing plasma volume

also increase TPR

Question 13

what is the Valsalva maneuverer

Answer 13

forced expiration against a closed glottis

Question 14

what happens during the Valsalva maneuverer

Answer 14

thoracic pressure increases - causing a decrease in venous return

Question 15

what does the wave of the Valsalva maneuverer work

Answer 15

sharp up, slowly down, sharp down, then up

Question 16

what does a decrease in Venous return lead to

Answer 16

decrease in EDV leading to decreased stroke volume, decreased Co and then in turn a decrease in MAP

Question 17

what dose the decrease in MAP lead to

Answer 17

detected by baroreceptors - increase CO and TPR

Question 18

what happens after the thoracic pressure is reduced

Answer 18

its transmitted through the aorta - and drops the BP

Question 19

what happens after the BP drops after reduced thoracic pressure

Answer 19

venous return is restored - stroke volume is restored, there’s a bit of a hump as the reflex effects hadn’t worn off

Question 20

what does angiotensin 2 do

Answer 20

cause arterial constriction -

Question 21

what does aldosterone do

Answer 21

increase Na+ reabsorption

therefore increase plasma volume - and increase BP

Question 22

what are the 3 hormonal long term controls

Answer 22

renin-angiogenesis-aldosterone system

antidiuretic factor (ADH, vasopressin)

atrial natriuretic peptide

Question 23

how do the kidneys regulates plasma volume

Answer 23

controlling the Na+ gradient

control over the permeability of the collecting ducts

determines how much water is retained

Question 24

what happens of the collecting duct is very permeable

Answer 24

it will result in conservation of water and in turn plasma volume

Question 25

what happens if the collecting duct was very impermeable

Answer 25

water will result in little reabsorption, lots of urine (= diuresis)

Question 26

how does the water move in and out

Answer 26

depending on the Na+ permeability creating hyper/hypo osmotic

Question 27

where is renin produced

Answer 27

the juxtaglomerular = granule cells of the kidney

Question 28

what triggers renin production

Answer 28

decreased distension of afferent arterioles decreased delivery of Na+ through tubule all signs of low MAP

Question 29

what does renin do

Answer 29

converts inactive angiotensinogen to angiotensin 1

Question 30

what does angiotensin 1 become what facilitates it

Answer 30

angiotensin 2 angiotensin converting enzyme

Question 31

what does angiotensin 2 do - what is it

Answer 31

stimulates released of aldosterone from the adrenal cortex increase release of ADH from pituitary is a vasoconstrictor negative feedback system in response to decreased MAP

Question 32

what is ADH

Answer 32

antidiuretic hormone

Question 33

where is ADH made/released from

Answer 33

synthesised in the hypothalamus released from the posterior pituitary

Question 34

what does ADH do

Answer 34

increase water permeability of the collecting duct to H2O reduces diuresis and increases plasma volume

Question 35

what is ADH alternative name

Answer 35

vasopressin causing vasoconstriction - increasing MAP

Question 36

what triggers ADH release

Answer 36

a decrease in blood volume circulating angiotensin 2

Question 37

what does aldosterone do

Answer 37

increases Na reabsorption in the loop of henle reduces diuresis

Question 38

where is aldosterone produced

Answer 38

from the adrenal cortex

Question 39

where is ANP produced

Answer 39

Produced in, and released from myocardial cells in the atria

Question 40

what does ANP stand for

Answer 40

Atrial natriuretic peptide

Question 41

what triggers atrial natriuretic peptide - what is this a sing of

Answer 41

increased distension of the atrium - a sing of increased MAP

Question 42

what does ANP do

Answer 42

increases excretion of Na+ inhibits the release of the renin reduces MAP

Question 43

what is ANP

Answer 43

a negative feedback system reduces MAP

Question 44

how many cases of hypertension are there

Answer 44

5-10%

Question 45

what are the treatments for hypertension

Answer 45

Ca2+ channel antagonists beta adrenoceptor antagonists thiazide diuretics angiotensin converting enzyme inhibitors