Blood Pressure and Pulse (Leaving Cert Biology): Revision Notes

Blood Pressure and Pulse

• Coronary arteries supply the cardiac muscle with blood. These branch from the aorta just above the semilunar valves.
• Coronary veins drains blood from the heart wall (the heart muscle) into the right atrium. This allows waste products and CO₂ to be removed from the heart tissue.

Pulse

• Pulse is the alternate expansion and contraction of arteries.
  • This occurs as a wave of expansion travels down the artery walls after the left ventricle contracts.
  • The elastic fibres in the artery walls then contract back.
  • The average pulse rate is 72 beats per minute.

Blood Pressure

• Blood pressure is the force that blood exerts on the walls of blood vessels.
  • As blood moves from arteries to veins, the pressure drops.
  • Blood pressure is measured with a sphygmomanometer, which records the pressure it takes to stop the blood flow in an artery of the upper arm.
  • Typical blood pressure is 120/80mmHg.
  • The higher value is the systolic value.
  • The lower value is the diastolic pressure.