cardiovascular system

Question 1

where does oxygenated blood enter the heart

Answer 1

pulmonary vein

Question 2

where does oxygenated blood leave the heard

Answer 2

aorta

Question 3

where does deoxygenated blood enter the heart

Answer 3

inferior and superior vena cava

Question 4

where does deoxygenated blood leave the heart and where does it go

Answer 4

pulmonary artery, goes to heart

Question 5

what is the arterial system made up of

Answer 5

layers of connective tissue and smooth muscle

Question 6

is there gaseous exchange in the arterial system?

Answer 6

no, too thick

Question 7

what are capillaries made up of

Answer 7

endothelial cells

Question 8

why is there slow blood velocity in capillaries

Answer 8

to allow full diffusion to take place

Question 9

what sort of blood flows through the venous system

Answer 9

mixed venous blood

Question 10

how does the venous system prevent back flow

Answer 10

contains valves

Question 11

name the 3 muscle layers of the heart

Answer 11

epicardium, myocardium, endocardium

Question 12

what is responsible for the second heart sound

Answer 12

the seminar valve closing

Question 13

how long does the cardiac cycle last at rest

Answer 13

0.8 seconds

Question 14

what happens during systole

Answer 14

heart is contracting and pumping out blood. SLV and AVV are closed

Question 15

what causes the semilunar valves to open after systole

Answer 15

pressure difference between atrium and ventricles

Question 16

what is end systolic volume

Answer 16

the volume of blood in ventricles at end of systole

Question 17

what % of blood is ejected after systole. what is this called

Answer 17

60%. stroke volume

Question 18

what happens during diastole

Answer 18

ventricles are filling, heart is in relaxed state

Question 19

what happens as pressure in atriums increase during diastole

Answer 19

AV valves open

Question 20

what % of ventricles gets filled passively due to pressure gradient

Answer 20

70%

Question 21

what is the natural pacemaker in the heart

Answer 21

the Sinoatrio node

Question 22

as well as the sinoatrio node, what other parts of the heart is the action potential sent through

Answer 22

AV node, AV bundle, Purkinje fibres

Question 23

why is the propagation of the action potential from the SA node to the AV node slow?

Answer 23

to allow both atriums to contract before ventricular contraction

Question 24

wear do the AV nodes (bundle of His) do

Answer 24

allow action potential to travel Down the atrium into ventricles

Question 25

what do the purkinje fibres do

Answer 25

allow the action potential to be distributed throughout the ventricle and contact the cardiac muscles to allow them to contract

Question 26

what is a membrane potential

Answer 26

difference in electric charge between extracellular and intracellular. In a cardiac cell it is -90mV

Question 27

what causes an action potential

Answer 27

a change in membrane potential

Question 28

what causes a change in membrane potential

Answer 28

the movement of ions across the cell membrane

Question 29

what ions pass over the cell membrane

Answer 29

potassium, sodium and calcium

Question 30

what is depolarisation

Answer 30

reduced membrane potential