vital role of cardiovascular system in maintaining homeostasis
it depends on the continuous and controlled movement of blood through the thousands of miles of capillaries
it is in the _____ that blood performs its ultimate transport function
capillaries
a muscular pump that provides the force necessary to circulate the blood to all the tissues in the body
heart
how many liters of blood does an adult heart pumps every minute
5 liters
how many chambers does a human heart have
4
the heart is enclosed in a _____
pericardial sac
encloses the heart and keeps it in a stable location mediastinum, facilitates its movements, and separates it from the lungs and other mediastinal structures
pericardial sac
3 layers of the heart wall:
epicardium
myocardium
endocardium
outer layer of the heart wall
epicardium
middle layers of the heart wall
myocardium
inner layer of the heart wall
endocardium
4 chambers of the human heart:
right ventricle
rightatrium
leftventricle
leftatrium
Differences in thickness of the heart chamber walls are due to variations in the amount of ______ present, which reflects the amount of force each chamber is required to generate.
myocardium
thin-walled chambers that receive blood from the veins
atria
thick-walled chambers that forcefully pump blood out of the heart
ventricles
receives deoxygenated blood from the body and pumps it to the right ventricle.
right atrium
pumps the deoxygenated blood to the lungs
right ventricle
receives oxygenated blood from the lungs and pumps it to the left ventricle
left atrium
pumps the oxygen-rich blood to the body.
left ventricle
allowing deoxygenated blood to leave the right ventricle and flow to the lungs via the pulmonary artery
pulmonary valve
its main function is to prevent back flow of blood from the pulmonary artery back into the Right Ventricle in DIASTOLE
pulmonary valve
ensure that oxygen-rich blood does not flow back into the left ventricle
aortic valve
to control the flow of blood from your heart's top chamber (right atrium) to the bottom chamber (right ventricle). This valve also helps prevent blood from flowing backward into either of these chambers.
tricuspid valve
regulates blood flow from the upper left chamber (left atrium) into the lower left chamber (left ventricle)
mitral valve
_____ from the heart muscle (the myocardium) cause the heart to contract.
Electrical impulses
heart's natural pacemaker
sinoatrial node
what causes the atria to contract
sinoatrial node
the contraction of _____ pushes blood through the tricuspid and mitral valves into the resting lower chambers (the right and left ventricles)
atria
the phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood.
diastole
this is when your heart contracts, pushing blood out of the chambers
systole
2 phases of the heart's pumping cycle
systole
diastole
The ______ in the ventricles causes the tricuspid and mitral valves to open, and the cycle begins again.
lower pressure
how many times does our heart beat in a minute when we are at rest?
60 to 80
as we get older, our resting heart rate _____
rises
fluid of life
blood
it transports oxygen from the lungs to the body tissue and carbon dioxide from body tissue to the lungs
blood
these are the channels or conduits through which blood is distributed to body tissues.
blood vessels
transports blood from the right ventricle to the lungs and back to the left atrium.