BIOL-2230 Lecture Notes - Lecture 8: Tricuspid Valve, Papillary Muscle, Pulmonary Artery
Document Summary
Biol 2230: lecture 8 (the heart and heart physiology) Atrioventricular valves: function to prevent back ow into the atria when ventricles contract, there are 2: Tricuspid valve-located in the right atria (r for right) Bicuspid (mitral) valve- located in the left atria. Cordae tendineae: these anchor the valves to the papillary muscles. Semilunar valves: these are valves at the aorta and pulmonary trunk that prevent back ow into the ventricles. Each have 3 cusps that look like crescent moons. Intercalated discs have both desmosomes and gap junctions: desmosomes prevent cell separation during contraction, gap junctions allow ions to pass from cell to cell. Causes electrical coupling which causes functional syncytium (moving as one) Autorhythmic cells make up 1% of cardiac bers and can depolarize at the same time: these cells will set the pace for the heart. They have an unstable resting potential which will continuously depolarize: initiates action potentials for rhythmic contraction.
