3.1.5 Pressure and Volume Changes in the Heart

L.O: to interpret graphs on the cardiac cycle

Starter: What animal has the highest blood pressure in the whole wide world?

What’s the keyword?

Activity1) Place your whiteboard on the table, use the

rulers as axes around the whiteboard

2) Divide the whiteboard into the three stages of the cardiac cycle (start with atrial systole)

3) Use one piece of wool to show the pressure changes in the atria

4) Use a different coloured piece of wool to show the pressure changes in the ventricles

Extension: Can you redo step 2 to think about how long each stage roughly lasts for?

Pressure Changes in the HeartAtrial

Systole DiastoleVentricular Systole

Pressure Changes in the HeartAtrial

Systole DiastoleVentricular Systole

Atria pressure increases due to contraction

Pressure Changes in the HeartAtrial

Systole DiastoleVentricular Systole

Atria pressure increases due to contraction

Atria pressure decreases as

atria relax

Pressure Changes in the HeartAtrial

Systole DiastoleVentricular Systole

Atria pressure increases due to contraction

Atria pressure increases as

atria fillAtria pressure decreases as

atria relax

Atrial Systole DiastoleVentricular

Systole

Atrial Systole DiastoleVentricular

Systole

Ventricular pressure increases slightly due to passive filling

Atrial Systole DiastoleVentricular

Systole

Ventricular pressure increases slightly due to passive filling

Ventricular pressure increases due to contraction

Atrial Systole DiastoleVentricular

Systole

Ventricular pressure increases slightly due to passive filling

Ventricular pressure increases due to contraction Ventricular

pressure decreases as ventricles relax

Atrial Systole DiastoleVentricular

Systole

Ventricular pressure increases slightly due to passive filling

Ventricular pressure increases due to contraction Ventricular

pressure decreases as ventricles relax

Ventricular pressure increases slightly due to passive filling

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 in the Heart

Match the letter on the graph to the following events

Semi-lunar valves openAtrio-ventricular valves close,

Semi-lunar valves closeAtrio-ventricular valves open

atrio-ventricular valves close

atrio-ventricular valves close

semi-lunar valves open

atrio-ventricular valves close

semi-lunar valves open

semi-lunar valves close

atrio-ventricular valves openatrio-ventricular valves close

semi-lunar valves open

semi-lunar valves close

I can describe the three main stages of the cardiac cycle

I can explain the how the heart is controlled by electrical impulses

I can interpret pressure and volume graphs on the cardiac cycle

Yes

Yes

Yes

Complete sheet A. Did you score over 85% ?

Use the AS revision guide page 40 and 41 to make notes

No

No

No

YesComplete sheet B.

What was your score?

Can you see where you went wrong? Ask me for help