Heart Anatomy Flashcards
Systole
Contraction
Diastole
relaxation
Who are the heart vessels?
Aorta, Vena Cava, Pulmonary artery, Pulmonary vein
Who are the heart chambers?
Left atrium, left ventricle, right atrium, right ventricle, septum (separation of left and right side)
Who are the valves
Aortic semilunar, pulmonary semilunar, right AV/tricuspid, Left AV/bicuspid/mitral
directions Apex ____
base___
base = top Apex= bottom
Cardiac conducting system who conducts action potential through the heart:
SA node, internodal pathways, AV node, Bundle branches, Purkinje fibers.
Pathway for Blood flow in the heart
deoxygenated blood from the systemic circulation pumps out to the superior vena cava and the interior vena cava and goes to the right atrium.
deoxygenated blood in the right atrium goes through the tricuspid right A/V valve to the right ventricle.
After the right ventricle contracts, it sends the blood to the right and left pulmonary arteries through the pulmonary semilunar valve.
Blood becomes oxygenated in the lungs.
Blood returns to the lungs through left and right pulmonary veins, then these oxygenated blood travels to the right atrium passes the left AV/mitral/bicuspid to get to the right ventricles, which then passes through aortic semilunar valve to the aorta/descending aorta.
Conducting system of the heart
Specialized muscle cells who conduct and generate action potential in the heart. Cardiac muscles have special autorhythmic cells who have pacemaker properties and can generate action potentials on their own.
Conduction pathway generalized
SA node: action potential generated here, top of the right atrium
Internodal pathways: spreads to the top of the heart
AV node: collects again at AV node and spread to the bottom of the heart through the septum
AV bundles
Bundle branches
Purkinjee fibers
What causes heart muscle to contract?
Action potentials
What is the most direct result of action potential?
changes in blood pressure
So generally, what happens is,
heart muscles contract, which causes changes in pressure, creates pressure gradient, which leads to a driving force pushing valves to open or close and allowing blood flow from one chamber to another.
Valves don’t have contractile tissues; they need to push with enough pressure to open or close. Ex:
Higher pressure in the atrium pushes valves to open and allows blood to flow in the right ventricle.
relaxation in muscle is due to lack of action potential, reduction in pressure, reversing pressure gradient, reversing drive force and causes the valve to slam shut.
