Cardiovascular Flashcards
3 Layers of the Heart
- Endocardium- Thin, smooth layer of epithelial cells that lines the heart’s interior.
- Myocardium- Heart muscle; thickest layer and pupls blood throught the vessels.
- Epicardium- Serous membrane that forms the thin, outermost layer of the heart wall. Also considered the visceral layer of the pericardium.
Pericardium
Sac that encloses the heart.
“Right Heart”
Receives blood low in oxygen content that has already passed through the body and pumps it to the lungs through the pulmonary circuit.
“Left Heart”
Receives highly oxygenated blood from the lungs and pumps it throughout the body via the systemic circuit.
Valves of the Heart
- Right and Left atrioventricular valves.
- Right AV (Tricuspid valve).
- Left AV (Bicuspid/Mitral valve).
- Right and Left semilunar valves.
- Right Semilunar (Pulmonary)
- Left Semilunar (Aortic)
Coronary Arteries
Supply blood to the muscle of the heart (myocardium).
Atrial Systole
Contraction of the atria pumps additional blood into the ventricles.
Ventricular Systole
Contraction of the ventricles pumps blood into aorta and pulmonary arteries.
Complete Diastole
Atria fill with blood, which flows directly into the relaxed ventricles.
SA Node
(Sinoatrial)
- Located in upper wall of the right atrium in a small depression.
- Initiates heart beats by generating an action potential.
- “Pacemaker” as it sets the rate of contractions.
AV Node
AV Bundle
Purkinje Fibers
(Atrioventricular)
- Located at the top of the interventricular septum.
- Fibers travel down both sides (Bundle of His) of interventricular septum (in the myocardium).
- Smaller Purkinje fibers travel in a branching network throughout myocardium of ventricles.
Cardiac Output
CO=HRxSV
(Heart rate; Stroke volume)
Arteries
Carry blood away from the heart, toward tissues. Ventricles pump blood into arteries.
Capillaries
- Tiny, thin walled vessels that allow for exchanges between systems.
- Connect arterioles and venules.
Veins
Return blood to the heart.
