The conduction system - how the heart works Flashcards
What does myogenic mean?
The capacity of the heart to generate its own impulses which cause the heart to contract.
Where do the impulses begin?
At the sino-atrial node.
The rate of impulses from the sino-atrial node = what?
Heart rate
What is the sino-atrial node made out of?
A mass of cardiac muscle cells.
Describe what happens when an impulse is emitted.
As the impulse is emitted, it spreads to the adjacent interconnecting fibres of the atrium, which spread the excitation extremely rapidly causing the atria to contract.
The sino-atrial node passes the excitation to another group of cardiac cells. What is this group called?
The atrio-ventricular node
Where does the AV node pass the excitation to?
The Bundle of HIS
Where does the Bundle of HIS pass the excitation to?
The purkinje fibres.
What do the purkinje fibres spread the excitation through and cause?
Through the ventricles causing them to contract.
