physiology

Question 1

main thing driving blood flow is

Answer 1

pressure
main thing driving pressure is
volume and distensibiltiu

Question 2

pulse pressure

Answer 2

systolic pressure - diastolic pressure

Question 3

Mean arterial pressure MAP

Answer 3

diastolic + 1/3 pulse pressure

Question 4

hypertension

Answer 4

greater than or equal to 90 mmHg for diastolic

greater than or equal to 140 mmHg for systolic

can have either or both of these in hypertension

Question 5

arteries -key properties

Answer 5

elastic

large diameter

Question 6

resistance in arteries vs arterioles

Answer 6

arteries= big diameter=little resistance
arterioles= small diameter=heaps of resistance

Question 7

active hyperaemia

Answer 7

\wen u e.g. run= increase metabolic activity of tissue= local chemical changes =causing vasodilation

Question 8

reactive hyperamei

Answer 8

block and then due to physical n chemical changes, get vasodilaiton n massive blood flow

Question 9

auto regulation of blood flow

Answer 9

increased stretch= increased contraction (constriction)

decreased stretch= decreased contraction (dilation

Question 10

prostacylcin PGI2

Answer 10

vasodilator

Question 11

EDHF

Answer 11

vasodilator

Question 12

endothelial stimulation to get it to vasodilate or vasoconrtstict:

Answer 12

sheer stress of blood flow
laminar flow=vasodilation
turbulent flow= reduced release of vasodialtion
• blood borne factors n subs released from platelets
• Ach , used as a tool –ie used in clinical

bifurication=turbulent flow= blood clot

Question 13

coronary angiography

for Ach

Answer 13

for Ach
if get vasodilation= endo is healthy
if get vasoconstriction= endo is impaired

Question 14

coronary angiography

for NTG

Answer 14

for NTG
this is any endothelium-independent vasodilator, so inserting it would be testing function of the smooth muscle
if get vasodilation=smooth musucle fine

Question 15

NO

Answer 15

vasodilator

Question 16

veins cos stretchy

Answer 16

big change in volume=small change in pressure

Question 17

sympathetic effect on veins

Answer 17

increased sympa stim on veins
contract muslces
makes walls stiff
less stretchy/distensible
increase venous pressure

Question 18

things that affect venous return

Answer 18

1. venous pressure=increase pressure=increase venous return
2. skeletal muscle pump
3. resp pump

Question 19

varicose vein

Answer 19

faulty valves

Question 20

vascular function

Answer 20

AS U INCREASE RIGHT ATRIAL PRESSURE, YOU DECREASE VENOUS RETURN

Question 21

the cardiac function

Answer 21

u increase right atrial pressure, U INCREASE END-DIASTOLIC VOLUME AND SO THEREFORE U INCREASE STROKE VOLUME

Question 22

response to haemorrhage

Answer 22

vasoconstriction
vasodilation\

take home message-fall in cardiac output is due to fall in venous return

Question 23

Mean Systemic (or circulatory) Filling Pressure (Psf)

Answer 23

pressure everywhere once u’ve stopped your heart

determined mainly by volume of blood and pressure in veins

Question 24

CO determined by

Answer 24

venous return

Question 25

MAP

Answer 25

CO x TPR

Question 26

cardiovascular system as a control system

Answer 26

``` baroreceptors sensory affernt nerves medullary cardiovascular centre efferent nerves heart, arterioles, veins ```

Question 27

baroreceptors

Answer 27

carotid sinus,arch of aorta

Question 28

baroreceptor reflex

Answer 28

increase in pressure stretches aorta n carotids baro increase firing send message to brain brain send para message back to heart telling it to slow HR n decrease sympa message to vessels =vasodilaite=decrease pressure incrase para decrease sympa SHORT TERM REGULATION cos get adaptation

Question 29

long term control of MAP is

Answer 29

renin system | • Pressure Diuresis/Natriuresis

Question 30

RAA system

Answer 30

wen MAP falls, blood flow falls • Renin released into circulation from juxtaglomerular cells in the kidneys • This plasma renin converts angiotensin(from liver) to angiotensin 1 • Angiotensin 1 then converted to angiotensin 2 via angiotensin-converting enzyme • Angiotensin 2 causes vessels to constrict, leading to increased blood pressure • Angiotensin 2 also stimulates secretion of aldosterone from adrenal cortex. Aldosterone tells kidney to increase reabsorption of sodium n water into blood=increase blood pressure as well

Question 31

stroke volume

Answer 31

edv-esv

Question 32

75%

Answer 32

• 75% of the Ca for cardiac contraction comes from the sarcoplasmic reticulum • 25% comes from ECF – exam question – Cardiac muscle cell placed in solution with no calcium won’t contract.

Question 33

cardiac output

Answer 33

volume of blood ejected per min

Question 34

SA action potential

Answer 34

NA n Ca constantly leaking in no fast voltage sensitive Na channel Ca channel open, upward positiveness K channel open- downwards

Question 35

tetrodotoxin

Answer 35

blocks fast voltage sensitive Na channel

Question 36

to increase filtration (pushing fluid out of capillaries)

Answer 36

dilate arterioles increase systemic arterial pressure increase venous pressure

Question 37

to increase reabsorption (pulling fluid back into capillaries)

Answer 37

constrict arterioles decrease systemic arterial pressure decrease venous pressure