Mammal Heart Function
Biology: Cambridge International GCSE Supplement, topic 9.2.1
The Heart Pumping
A group of cells in the right atrium act as a pacemaker, controlling the pumping heart. When a heart beats:
Blood enters via the atria
- Blood enters the heart via the atria.
Atria contract
- Once filled with blood, the atria contract, forcing blood down into the ventricles below.
Ventricles contract
- When the ventricles contract, they force blood to exit the heart.
Test yourself on Mammal Heart Function
- Which structures stop blood flowing backwards in the heart?
- Where else is backflow a problem?
Why might someone be fitted with an artificial pacemaker?
The Beating Heart