PHAR 471 Lecture Notes - Lecture 4: Cardiac Output, Arteriolosclerosis, Angiotensin
10 Dec 2016
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Document Summary
= pressure inside the blood vessels/heart relative to atmospheric pressure (mmhg); exerted on blood vessel walls. Cardiac output (co) amount of blood/time (l/min) = heart rate (beats/min) x stroke volume (volume pumped/beat) Peripheral vascular resistance (pvr) resistance through precapillary arterioles. The body will maintain bp by changing co or pvr if co increases, pvr will decrease (and vice versa) Diastolic blood pressure = blood pressure after cardiac contraction (diastole) Systolic blood pressure = blood pressure during cardiac contraction. Mean arterial pressure = average pressure through the cardiac cycle. Map = (2dbp + sbp)/3 dbp is doubled because it takes twice as long. Can be used as a measure of cardiac wall or aortic stiffness/tension. Aorta absorbs high pressure stress on cardiac emptying to buffer pulse pressure into the body. Cardiac stiffness = sv = narrow/decreased pulse pressure. Aortic stiffness = afterload (the blood is pumping against a higher force) = sbp = wider/larger pulse pressure.
