1. Blood Pressure

2. Blood pressure is the force exerted by the blood against the walls of the blood vessels. It is necessary to maintain blood flow though the circulatory system It is determined by two main factors – 1)Cardiac Output – the volume of blood flowing into the system from the left ventricle. 2)Resistance to flow – the impedance offered by the blood vessels to the blood flow.

3. Blood Pressure Blood pressure = cardiac output x resistance Therefore, blood pressure increases when either cardiac output or resistance increases. Blood pressure in the arteries also increases and decrease in a pattern which corresponds to the cardiac cycle during ventricular systole, when blood is pumped into the aorta and lowest during ventricular diastole.

4. Blood Pressure Measurement BP is usually measured a the brachial artery using a sphygmomanometer, and is recorded as mmHg of systolic pressure over diastolic pressure: SYSTOLE pressure is experienced when the heart pumps blood into the system DIASTOLIC pressure is recorded when the heart is relaxing and filling with blood. Typical Reading = 120mmHg 80mmHg

5. Blood Pressure and Exercise BP Changes during exercise. During Aerobic exercise, the systolic pressure increases as a result of increased cardiac output, while diastolic pressure remains constant, or in well trained athletes may even drop as blood feeds into the working muscles. During isometric or anaerobic exercise both systolic and diastolic pressure rise significantly due to increased resistance of the blood vessels.