|the pressure exerted by the blood on the inner walls of the arteries, being relative to the elasticity and diameter of the vessels and the force of the heartbeat|
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
blood pressure n.
Abbr. BP, B.P. The pressure exerted by the blood against the walls of the arteries, maintained by the contraction of the left ventricle, the resistance of the arterioles and capillaries, the elasticity of the arterial walls, and by the viscosity and volume of the blood. Also called arteriotony.
The pressure of the blood in the vessels, especially the arteries, as it circulates through the body. Blood pressure varies with the strength of the heartbeat, the volume of blood being pumped, and the elasticity of the blood vessels. Arterial blood pressure is usually measured by means of a sphygmomanometer and reported in millimeters of mercury as a fraction, with the numerator equal to the blood pressure during systole and the denominator equal to the blood pressure during diastole. See more at hypertension, hypotension.
The pressure of the blood against the walls of the blood vessels, especially the arteries. It is expressed in two figures, said to be one “over” the other: the systolic pressure, which is the pressure when the left ventricle of the heart contracts to push the blood through the body; and the diastolic pressure, which is the pressure when the ventricle relaxes and fills with blood. Blood pressure is affected by the strength of the heartbeat, the volume of blood in the body, the elasticity of the blood vessels, and the age and general health of the person. (See circulatory system.)