Ch 12 Cardiovascular Physiology Finish Section A Begin Section B The Heart Lab is ~ 2hrs this week SPSS Abstracts due 7 Nov Editorial help before submission?

What’s missing? Microcirculation Exchange Vessels Pulmonary circuit 5 liters/min 5 liters/min Systemic Circuit Resistance Vessels Microcirculation Exchange Vessels Capacitance vessels

Q= ΔP πr4 8Lη Poiseulle’s equation Flow = Pressure gradient/Resistance A version of Ohm’s Law (V=IR) Radius of arterioles regulates Q to organs Double radius … 16x flow Half radius….1/16th flow R = 8Lη/πr4 Q= ΔP πr4 8Lη Poiseulle’s equation Smooth muscles determine radius

Cardiac Output = Heart Rate X Stroke Volume CO = HR x SV 5L/min = 72 beat/min x 70 ml/beat

Figure 12.07 Tricuspid Bicuspid =Mitral Problems with valves: ….Stenosis (narrowing) →Heart Murmurs (turbulent flow past a constriction) note: origin of neonatal heat murmurs (foramen ovale) ….Prolapse (eversion) allows backflow (also generates murmurs) Figure 12.07 Bicuspid =Mitral Tricuspid Heart sounds and valve closings Semilunar Valves

Figure 12.11 SA node cells spontaneously produce AP, do not have stable resting membrane potential, are Pacemaker cells

Figure 12.25 Contractility