Structure and Function of Circulatory System Flashcards
How many valves does the heart have?
two
Atrioventricular Valves (AV)
maintain unidirectional blood flow between atria and ventricles
Tricuspid and Bicuspid Valve locations
T - on the right of the atrioventricular
B - on the left of the atrioventricular
Semilunar Valves
Ensure one-way flow out of ventricles to arterial systems.
Pulmonary and Aortic Valves location
P - located at exit of right ventricle
A - located at exit of left ventricle
_____ open and close as heart goes through cardiac cycle.
valves
Diastole
ventricles relaxed and filling
Systole
ventricles contracted and pumping
“Lub” and “Dub” sounds
Lub - AV valves closing
Dub - closing of semilunar valves
Myocardial contractile cells
“self-excitable” auto rhythmic fibers
Sinoatrial Node (SA) : location and definition
- Located in wall of right atrium
- Natural pacemaker where automatic nervous system modulates rate
5 important steps in the heart beat
- impulse begins at SA node and travels to AV node
- impulse travels to AV bundle
- impulse travels down inter ventricular septum
- impulse spreads to branches
- impulse reaches the Purkinje Fibers and is distributed throughout ventricles.
Right and Left Pulmonary Arteries
deliver oxygen-depleted blood from right ventricle to right and left lungs.
Pulmonary Veins
return oxygenated blood from lungs to left atrium of heart.
Aorta and Branches
systematic arteries that carry oxygen-rich blood from left ventricle to the body.
