BIOL 3060 Lecture Notes - Lecture 11: Purkinje Fibers, Papillary Muscle, Peripheral Nervous System
Document Summary
Autonomic regulation of the heart: ans is involuntary peripheral nervous system that controls the viscera, there is still some voluntary control to regulate hr. To make sure that the apex contracts before the rest of the ventricles. Looked at heart rate changes due to ach and noradrenaline. If pressure goes down, it means heart is not pumping enough blood = feedback. Pressure is a main determinant of hr, done by antagonistic control of both sns and pns. That"s (cid:449)hy the cells are called pace maker cells: atrial and ventricular mcs are working cms, involved in pumping, cms of sa node have different channels. In sa node, starts with a negative membrane potential and increases as a function of time. A: average hr is about 60 = 1 beat per sec. depolarizing sa cells drive atria, every time threshold (-40 for ca channels) is crossed it sends an. They are regulated by camp, slaves to sns and beta adrenergic receptors.
