PSL201Y1 Lecture Notes - Lecture 14: Diastole, Circulatory System, Pulmonary Vein
Document Summary
Psl201 lecture 14 reading notes; cardiovascular physiology 3. The cardiac cycle- integrated events in cardiac function. One event is dependent upon the others. Contraction produces pressure changes that leads to blood flow. Blood flows from high pressure to low pressure. Events on the right side are the same as the left side but the pressures are lower on the right side. Diastole: rest cycle where the heart fills. Systole: active cycle where the heart empties. Isovolumic: volume doesn"t (cid:272)hange (cid:894)(cid:271)ut pressure does(cid:895); applies to (cid:271)oth relaxation and (cid:272)ontra(cid:272)tion. Most of the cardiac cycle is spend in diastole. Longer diastole gives heart adequate time to fill with blood and gives heart muscle more time to relax preventing fatigue. During mid to late diastole blood returning to the heart via the systemic and pulmonary veins enters the relaxed atria and passes through the av valves and into the ventricles under its own pressure.
