Blood Pressure

Blood pressure is the force exerted by the blood on the walls of the articles. When the powerful left ventricle contracts to pump blood throughout the body, the arteries receive more blood than can be instantly moved through the tiny arterioles and capillaries. Therefore, there is always a great deal of inner pressure in the arteries. Like liquid being poured into a funnel, blood pools up in an artery before entering the smaller areas of the circulatory network; healthy arteries are elastic and expand to accommodate the load.

Blood pressure is measured at two points during the beating of the heart:

1. When the left ventricle is actually pumping blood, and
2. When the left ventricle is relaxing and filling up with blood for the next pumping cycle.
3. The heart beat phase, or systolic phase the pressure to rise, while the resting phase or diastolic phase, brings the pressure down.

Much as air pressure in auto tires is measured in pounds per square inch, blood pressure is measured in millimeters of mercury. It is measured by means of an inflatable cuff, called a sphygmomanometer, that is wrapped around the upper arm. Everyone should have his or her blood pressure checked regularly. Many public agencies, and private companies, such as television stations, offer such checks to the public free of charge.