cardiovascular system

Question 1

what is stroke volume

Answer 1

volume of blood pumped out of heart per beat

Question 2

what is cardiac output

Answer 2

amount of blood that leaves the left ventricle per minute

Question 3

heart rate

Answer 3

heart contractions per minute

Question 4

formula for cardiac volume

Answer 4

stroke volume x heart rate

Question 5

units for heart rate, stroke volume and cardiac

Answer 5

HR= bpm
SV= ml
Q= l/min

Question 6

what does myogenic mean

Answer 6

self regulating

Question 7

what is the all or non law

Answer 7

how nerve cells either fire at full strength or do not.

Question 8

what do chemoreceptors detect

Answer 8

chemical changes:
-pH
-02 levels
-CO2 levels

Question 9

what do baroreceptors detect

Answer 9

blood pressure levels

Question 10

what do proprioreceptors detect

Answer 10

muscle movement

Question 11

what does hormonal control release

Answer 11

adrenaline to SA node

Question 12

what does intrinsic control detect

Answer 12

temperature change

Question 13

what happens during diastole

Answer 13

SA node repolarises while atria fills with blood. some of this blood passively drips into ventricles

Question 14

what happens during atrial systole

Answer 14

SA node sends an impulse across the stria for it to contract which opens the valves and blood fills up the ventricles.

Question 15

what happens during ventricular systole

Answer 15

the SA node sends an impulse to AV node which holds it until ventricle are filled then sends it down the Bundle Of His to the purkinje fibres where the ventricle walls contract pushing blood up and out

Question 16

what is ejection fraction

Answer 16

blood left in ventricles after majority of it was pushed up and out

Question 17

what does the arterioles and pre-capillary sphincters to working muscles/ organs do

Answer 17

-smooth muscle in arterioles vasodilate
-pre-capillary sphincters relax

Question 18

what does the arterioles and pre-capillary sphincters to non-working muscles/ organs do

Answer 18

–smooth muscle in arterioles vasoconstrict
-pre-capillary sphincters contract

Question 19

what is the systolic phase

Answer 19

when the heart contracts to push blood out of the heart

Question 20

describe intrinsic control

Answer 20

-as temp increases the viscosity of blood decreases, can flow more fluidly.
-increases nerve transmissions which increases nerve transmissions and firing rate of SA node

Question 21

mechanisms of venous return

Answer 21

respiratory pump
gravity
smooth muscle in blood vessels
skeletal pump

Question 22

what affects does increasing temperature of the blood have (intrinsic control)

Answer 22

decreases blood viscosity - blood flows more freely
venous return increases-more powerful contractions
increases stretch of atrial walls
increases firing frequency of SA node

Question 23

neural control of vascular shunt at the start of exercise

Answer 23

-chemoreceptors detect increase in CO2, decrease O2 and decrease in pH
-bari receptors detect increase in bp
-This information is sent to VCC
-smooth muscles in artérioles at working muscles are stimulated by the sympathetic nerve to vasodilate
-pre capillary sphincters are working muscles relax to
-this allows more blood flow
-smooth muscles in artérioles to non essential organs vasoconstrict
-pre capillary sphincters contract
-restricts blood flow

Question 24

what is venous return

Answer 24

the rate of blood flow back to the heart

Question 25

what are the changes in dissociation during exercise

Answer 25

-Bohr shift takes place, curve shifts to the right
-this increases CO2 levels, decreases pH, increases temperature
-this causes a reduced affinity of haemoglobin for O2
-this makes oxygen more available for diffusion into the muscles