BIOM20002 Lecture Notes - Lecture 48: Cardiac Cycle, Pulmonary Circulation, Pulse Pressure
Document Summary
A and v? all cells in a and v contract together. Passes ap from one to the next instead of individually being innervated. Yellow is non-conductive fibrous connective tissue - provides insulation. Pulmonary circulation has less pressure - less interstitiual fluid between alveoli and capillaries for gas exchange. Ventricular systole: period of time where v contracts. Ventricular diastole: period of time where v relaxes. Heart contracts and relaxes so bp follows a sinusoidal curve. Pulse pressure is the difference between these which is the pressure actually exerted by heart. Most movement from atria to ventricles is passive (but they do contract)-->ventricles contract to push blood out. Arrhythmic cells can contract but their ap generating properties are most important. Pacemaker ~70bpm: sa nodes beat in a petri dish at 70bpm. Because this is fastest, it leads - causes av node to also beat at 70bpm. Av node (50bpm): slightly different channel properties regulating if.
