BIOL 221 Lecture Notes - Lecture 4: Korotkoff Sounds, Sphygmomanometer, Auscultation
11 Feb 2020
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Document Summary
Systemic diastolic pressures in the range from 60 to 80 mm hg are considered normal. Pressures lower than 60 or higher than 80 mm hg are abnormal and will be discussed later. Note that pulmonary systolic pressures are significantly lower. Again, this is because of the lower resistance offered by the vasculature of the pulmonary system. Recoil of the elastic arteries during diastole helps to maintain pressure on the blood and keep it flowing while the ventricles are at rest. The elastic arteries expand during the ejection period of systole. The elastic arterioles recoil during diastole (imagine releasing the tension on a stretched rubber band). Arteriosclerosis is a progressive disorder in which elasticity is lost. Systemic arterial blood pressure is measured using the auscultatory method; that is, by listening for sounds heard through a stethoscope. Typically a sphygmomanometer (blood pressure cuff) is used to occlude the brachial artery, which is the large muscular artery of the brachial region.
