cardiovascular system Flashcards
where does oxygenated blood enter the heart
pulmonary vein
where does oxygenated blood leave the heard
aorta
where does deoxygenated blood enter the heart
inferior and superior vena cava
where does deoxygenated blood leave the heart and where does it go
pulmonary artery, goes to heart
what is the arterial system made up of
layers of connective tissue and smooth muscle
is there gaseous exchange in the arterial system?
no, too thick
what are capillaries made up of
endothelial cells
why is there slow blood velocity in capillaries
to allow full diffusion to take place
what sort of blood flows through the venous system
mixed venous blood
how does the venous system prevent back flow
contains valves
name the 3 muscle layers of the heart
epicardium, myocardium, endocardium
what is responsible for the second heart sound
the seminar valve closing
how long does the cardiac cycle last at rest
0.8 seconds
what happens during systole
heart is contracting and pumping out blood. SLV and AVV are closed
what causes the semilunar valves to open after systole
pressure difference between atrium and ventricles
what is end systolic volume
the volume of blood in ventricles at end of systole
what % of blood is ejected after systole. what is this called
60%. stroke volume
what happens during diastole
ventricles are filling, heart is in relaxed state
what happens as pressure in atriums increase during diastole
AV valves open
what % of ventricles gets filled passively due to pressure gradient
70%
what is the natural pacemaker in the heart
the Sinoatrio node
as well as the sinoatrio node, what other parts of the heart is the action potential sent through
AV node, AV bundle, Purkinje fibres
why is the propagation of the action potential from the SA node to the AV node slow?
to allow both atriums to contract before ventricular contraction
wear do the AV nodes (bundle of His) do
allow action potential to travel Down the atrium into ventricles
