NURS 216 Study Guide - Final Guide: Abdominal Aortic Aneurysm, Coronary Artery Disease, Aortic Valve
Document Summary
Effects of gravity: volume and pressure, one influences the other. Pressure is highest in the arteries, lowest in the veins. Higher resistance means less blood flow: resistance is affected by radius of the vessel and blood viscosity. Ideally, blood flow is laminar, not turbulent: wall tension, radius, and pressure, wall tension: the force inside the vessel wall that opposes hydrostatic pressure, laplace law: p = t/r may restate: t = p*r. Anywhere from 4 to 8 l/min: preload = edv, volume work or prestretch . It is called the preload because it is the work or load imposed on the heart before contraction begins: the amount of blood that is returned via the venous system to the heart, both right and left sides. The amount of blood the heart must pump with each beat. Represents the volume of blood stretching the ventricular muscle fibers at the end of diastole (i. e. end-diastolic volume)
