大象传媒

Structure and function of the heartBlood pressure

In this Higher Human Biology revision guide, you will learn in detail that cardiac output is a measure of the rate of blood flow through the heart and its associated blood vessels. You can also revise the blood vessels leading into and out of the heart, the cardiac conduction system, and autonomic and hormonal control.

Part of Human BiologyPhysiology and Health

Blood pressure

Blood pressure being monitored
Image caption,
Blood pressure being monitored

As the heart contracts and relaxes, blood pressure rises and falls. Blood pressure increases during ventricular systole and decreases during diastole.

Blood pressure can be measured using a sphygmomanometer. It measures two values:

  • systolic value 鈥 blood pressure while the heart is squeezing
  • diastolic value 鈥 blood pressure while the heart is relaxing

Average blood pressure for an adult in 120/80 mmHg.

High blood pressure is known as hypertension and is a major risk factor for developing many cardiovascular diseases.