· Right Ventricle Tricuspid Valve RightAtrium Pulmonary Valve Lungs
Pulmonary veins Left Ventricle Bicuspid Valve LeftAtrium Aortic Valve Aorta
Superior/Inferior vena cava + Coronary Right ventricle
· Histology: Cardiomyocyte have desmososmes and gap junctions, intercalated disks,
nucleus, sarcolemma and tons of mitochondria.
· cardiomyocyte AP: has a much slower repolarization due to a plateau period in which
Ca2+ flows into cell and K+ flows out.
· Excitation:AP enters from other cell, opens voltage gated Ca channels, triggers release
of Ca through SR, Ca binds to troponin to initiate contraction, Ca unbinds to troponin to
initiate relaxation, Ca is pumped back into SR and Na+ gradient is maintained with
Sodium potassium ATPase, makes ATP to support heart energy.
· No fatigue- ATP sources within heart muscle- ALL aerobic, myoglobin reserve, LOTS
of mitochondria, oxidation of FA= 60% of energy supply at rest, 35% from glucose
Auto rhythmic cell (SA node) action potential- No resting membrane po