Blood pressure

pressure exerted by circulating blood upon the walls of blood vessels

A sphygmomanometer ( ), also known as a blood pressure monitor, blood pressure machine, or blood pressure gauge, is a device used to measure blood pressure, composed of an inflatable cuff to collapse and then release the artery under the cuff in a controlled manner, and a mercury or aneroid manometer to measure the pressure. Manual sphygmomanometers are used with a stethoscope when using the auscultatory technique.

thumb|upright=1.5|Early ventricular diastole is the filling of blood from the atria (from the left atrium shown in pink, and from the right atrium shown in blue) that weakly contract letting blood fill into the ventricles; in late ventricular diastole, the two atria begin to contract (atrial systole), forcing additional blood flow into the ventricles.

thumb|upright=1.5|The cardiac cycle at the point of beginning a ventricular systole, or contraction: 1) newly oxygenated blood (red arrow) in the left ventricle begins pulsing through the aortic valve to supply all body systems; 2) oxygen-depleted blood (blue arrow) in the right ventricle begins pulsing through the pulmonic (pulmonary) valve en route to the lungs for reoxygenation. Systole ( ) is the part of the cardiac cycle during which some chambers of the heart contract after refilling with blood. Its contrasting phase is diastole, the relaxed phase of the cardiac cycle when the chambers o

pressure inside the skull and thus in the brain tissue and cerebrospinal fluid

sounds listened for when taking blood pressure

difference between the systolic and diastolic pressure readings

average blood pressure in an individual

400px|thumb|Flowchart showing baroreceptor reflex

300px|thumb|A sphygmograph, probably of Etienne-Jules Marey's design The sphygmograph ( ) was a mechanical device used to measure blood pressure in the mid-19th century. It was developed in 1854 by German physiologist Karl von Vierordt (1818–1884). It is considered the first external, non-intrusive device used to estimate blood pressure.

technique for measuring blood pressure over regular intervals

standard diagram used in cardiac physiology named after Dr. Carl J. Wiggers

techniques for determining blood pressure

Prehypertension, also known as high normal blood pressure and borderline hypertensive (BH), is a medical classification for cases where a person's blood pressure is elevated above optimal or normal, but not to the level considered hypertension (high blood pressure). Prehypertension is now referred to as "elevated blood pressure" by the American College of Cardiology (ACC) and the American Heart Association (AHA). The ACC/AHA define elevated blood pressure as readings with a systolic pressure from 120 to 129 mm Hg and a diastolic pressure under 80 mm Hg. Readings greater than or equal to 1

blood pressure at the root of aorta

blood pressure in the hepatic portal vein, normally between 5-10 mmHg