Download Cardiac Cycle - MrsSconyersAnatomy

Cardiac Cycle
Ch. 20-2
Heart
• Double pump
&double
circuit
Heart Valves
• Valves – allow one way flow of blood
• 4 total valves
• 2 atrioventricular (AV) valves
– Left AV valve (bicuspid or mitral valve) – between LA
and LV
– Right AV valve (tricuspid valve) – between RA and RV
• 2 semilunar valves
– Aortic semilunar (aortic valve) – between LV and aorta
– Pulmonary semilunar (pulmonary) – between RV and
pulmonary artery
Heart Valves
Path of Blood Flow
•
•
•
•
•
•
•
•
From the body into heart through vena cava
Into RA
Into RV
Out to lungs through pulmonary arteries
Into heart from lungs through pulmonary veins
Into LA
Into LV
Out to body through aorta
Path of Blood Flow
Path of Blood Flow
Name the Valves
Heart Actions
• Cardiac Cycle – one complete heart beat
• Contraction of heart chamber – systole
• Relaxation of heart chamber – diastole
Contraction Cycle
Valve Control
• Cusps (flaps) of
bicuspid and tricuspid
valves are anchored to
walls of ventricles by
“cords” (heart strings)
– chordae tendineae
• This prevents valves
from being pushed up
into the atria during
ventricular systole
Heart Sounds
• Lub-dup – opening and closing of the valves
• Sound byte
http://www.ilovewavs.com/Effects/People/So
und%20Effect%20%20Heart%20Beat%2001.wav
Cardiac Conduction
• SA node
• Right and left
bundle branches
• AV node
• AV bundle
• Perkinje fibers
Cardiac Conduction
Name the Parts
Review
• What are the two circulatory systems? What do
they do?
• Where is the heart located?
• What is the pericardium? What three layers does
it contain?
• Describe the main structures of the heart.
• Describe the valves of the heart.
• What is the cardiac cycle?
• What are the heart strings? What do they do?
• Describe cardiac conduction.