PSL201Y1 Lecture Notes - Lecture 16: Purkinje Fibers, Rectifier, Intercalated Disc
Document Summary
The heart is on the ventral side of the thoracic cavity, sandwiched between the lungs. Encased within a membranous fluid-filled sac called pericardium. The ventricles occupy the bulk of the heart. The arteries and veins all attach to the base of the heart. Valves: keep blood flow in proper direction within heart; b/w heart and arteries connected directly to it (aorta and pulmonary trunk) One-way flow throughout theheart is ensured by two sets of valves: cusp of left av (bicuspid) valve and cusp of right av (tricuspid) valve. Prolapse of the av valves are prevented b/c valve cusps are held in place by strands of ct called chordae tendineae. > when the ventricles are relaxed, blood enters atria, pushing the av cusps down into the ventricles, opening the valves. > when the ventricles contract, blood presses up against the av cusps, forcing the valves closed.
