BIOL 4510 Lecture Notes - Cardiac Cycle, Papillary Muscle, Atrioventricular Node
Document Summary
Items discussed in class and added to the notes: Related to the cardiac conduction system and the ecg. The cardiac conducting system ensures orderly contraction of the heart. Ensures that contraction starts at the apex (and papillary muscles) and progresses towards the base of the heart. There are often extra- nodal tracks connecting the atria and ventricles (i. e. connections in addition to the av node). These extra connections are made of myocytes that have properties similar to atrial or ventricular myocytes and therefore they conduct electricity quickly. This means that the atria can (pre)excite the ventricles through the extra path before the av node excites the ventricles. In wpw patients, there is little or no time between the end of the p-wave and the beginning of the qrs. Normally there is virtually no pressure difference between the atria and the ventricles when the av valves are opened.
