NURS 403 Lecture Notes - Lecture 1: Pulmonary Valve, Mitral Valve, Aortic Valve
Document Summary
Nurs 403: concepts of acute and critical illness. Review of anatomy and physiology: the cardiovascular system consists of the heart, a muscular pump, and the blood vessels. The blood vessels are arranged in two continuous loops: the pulmonary circulation and the systemic circulation. When the heart contracts, it pumps blood simultaneously into both loops. Conduction: the heart has a unique ability: automaticity, the heart can contract by itself, independently of any signals or stimulation from the body. Av node controls how much the ventricular rate is: conduction problem may indicate wide qrs, p wave (atrial depolarization, qrs (ventricular depolarization) 15-40: damage to sa node, av node controls and takes over. Isovolumic contraction: ventricular depolarization from qrs depolarizes septum and papillary muscles. Isovolumic relaxation: occurs btwn closed semilunar valves (aortic & pulmonary) and opening of av valves. All 4 valves closed, pressure within ventricle falls below atria without any change in vol: ventricular diastole: av opens, majority of ventricular filling occurs.
