The Cardiovascular System:
Structure and Function
Organs of the Cardiovascular System
Heart
Blood vessels
– Arteries
– Veins
– Capillaries
Double circulation
Heart structure
Coronary arteries
Cardiac cycle
Atrial systole
Both atria contract and
force the blood into the
ventricles.
Bicuspid and tricuspid
valves are open,
semilunar valves are
closed.
Lasts about 0.1 seconds
Ventricular systole
Both ventricles
contract and pressure
increases.
Blood is forced to the
pulmonary vein and
aorta.
Semilunar valves
open, bicuspid and
tricuspid valves close.
Lasts about 0.3
seconds.
Cardiac diastole
Both atria and
ventricles relax.
Blood flows into the
heart from the veins.
The atrioventricular
valves (bicuspid and
tricuspid) slightly
open.
The semilunar valves
shut.
Lasts about 0.5
seconds.
Electrocardiogram (ECG)
Heart attack
Angioplasty and stenting