Cardiac cycle control of heart beat Flashcards
(15 cards)
What is the cardiac cycle?
It is the period between the start of one heartbeat and the beginning of the next heartbeat.
At what stage is the heart is filled with blood and the muscle in the atrial wall contracts?
The Atrial systole
At what stage do both ventricles contract?
The Ventricular systole
When do the Ventricles and atria relax?
In the ventricular diastole
The cardiac cycle is initiated in a specialized patch of muscle in the wall called?
Sinoatrial node
The sinoatrial node is also known as?
SAN or pacemaker
Which contract first, the muscles of ventricles or atria?
The muscles of the atria contract first
What is the route through a patch of conducting fibers, situated in the septum called?
Atrioventricular node or AVN
What picks up the excitation wave and spreads it across the atria?
the AVN
After the AVN spreads the excitation wave across the atria, what conducting fibers does it pass it to?
The purkyne tissue
What is fibrillation?
In which the heart wall simply flutters rather than contract as a whole and then relax as a whole.
How can fibrillation start?
an electric shock or by damage to large areas of muscles in the walls of the heart.
Cardiac muscles differ from the muscles in other areas of our body because it is?
Myogenic
What does it mean that cardiac muscles are myogenic?
They naturally contract and relaxes.
What are the three stages of the cardiac cycle?
Atrial systole
Ventricular systole
Diastole
