heart action

Question 1

what does myogenic mean?

Answer 1

the heart’s contraction is initiated from within the muscle itself, rather than by the nerve impulses

Question 2

explain how the heart contracts

Answer 2

• SAN initiates and spreads impulse across the atria so they contact
• AVN receives, delays and then conveys the impulse down the bundle of His
• impulse then travels into the Purkinje fibres which branch across the ventricles, so they contract from the bottom up