Final answer:
Blood pressure is the force exerted by blood on the walls of blood vessels, primarily caused by the beating of the heart. It is measured in millimeters of mercury and expressed as a double number representing systolic and diastolic pressure. Normal blood pressure is generally defined as less than 120/80 mmHg.
Step-by-step explanation:
Blood pressure is the force exerted by blood on the walls of blood vessels. It is primarily caused by the beating of the heart. The highest pressure occurs in the arteries, while the pressure decreases as blood moves into smaller blood vessels and veins. Blood pressure is measured in millimeters of mercury (mmHg) and is expressed as a double number, with the higher number representing systolic pressure and the lower number representing diastolic pressure. Normal blood pressure is generally defined as less than 120 mmHg (systolic) and 80 mmHg (diastolic).