BIOL 2120K Lecture Notes - Lecture 8: Atrioventricular Node, Sympathetic Nervous System, Sensory System
Document Summary
Normal bp - 120/80 mean arterial blood pressure = 1/3 disatole + 1/3 diastole + 1/3 systole = diastole + 1/3 (pulse pressure) Diameter is the most important factor for blood flow. Less volume (water) more solid (concentrated) then it moves slower. Vessel length (number of vessels; if you gain weight or grow; vasculature grows) = increased resistance (increased blood pressure) Blood volume = amount of water in blood. Totally vaso-dilated - loose, large diamter; low pressure; no flow. Co (cardiac output) = p / r or p = co * r. If there is lots of stretching caused by high blood pressure. Sensory neurons tell sns to activate parasympathetic, parasympathetic sends innervation back into the heart. Sa node and av node - controls heart rate (electrical activity). If there is decreased stretch (low blood pressure). Sensory input goes back to sensory nervous system. Sympathetic innervates the heart at the sa node, av node and myocardium.
