Pressure and Volume Changes in the Cardiac Cycle

L.O: to label events in the cardiac cycle on a graph

Starter: Complete the ‘Heart Cycle’ worksheet by numbering the statements into the correct order.

Blood Pressure• Systolic pressure is the

pressure at which the blood leaves the heart through the aorta.

• Diastolic pressure is the minimum blood pressure in the aorta.

• Blood pressure can be measured with a sphygmomanometer: first reading is systolic and second is diastolic then represented as a fraction.

Systolic Diastolic

< normal < 100 < 60

Normal 100-139 60-89

Borderline 140-159 90-94

Hyper-tension

>159 >94

Volume Changes

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Time (secs)

Volume of left ventricle (cm3 )

150

100

0

Atrial Ventricular Ventricular

Systole Systole Diastole

Volume Changes

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Time (secs)

Volume of left ventricle (cm3 )

150

100

0

Atrial Ventricular Ventricular

Systole Systole Diastole

Thinking task! What do you think the line would look like?

Volume Changes

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Time (secs)

Volume of left ventricle (cm3 )

150

100

0

Atrial Ventricular Ventricular

Systole Systole Diastole

Pressure Changes

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Time (secs)

Pressure of left ventricle (kPa)

150

100

0

Atrial Ventricular Ventricular

Systole Systole Diastole