0
less than 0.08 seconds
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
When does a QRS complex occurs?
When ventricles depolarize
What does the sinoatrialnode release when it fires?
An action-potential which then travels to the Bundle of His and then the purkinje fibers to depolarize the ventricles to cause contraction.
The stage of the heart cycle in which the heart muscle contacts and the chambers pump blood?
The sinoatrial node depolarizes the atria and causes them to contract which tops up the ventricles with blood, the signal then moves through the atrioventricular node and then the atrioventricular bundle and into the purkinje fibres which causes the ventricles to depolarize and contract sending blood from the right ventricle to the lungs and from the left ventricle. The Atria repolarizes at the same time as the ventricles depolarize and then a fraction of a second later the ventricles repolarize and the cycle begins again.
Why does the QRS complex have the largest amplitude?
More cells depolarize during this QRS complex(ventricular contraction). The reason is because the muscle mass of the atria is small compared with that of the ventricles. The ventricles have a larger muscle mass. Therfore the electrical impulses within the atria are shorter and are less. The ventricles are larger so there is a larger deflection of the ECG when the ventricles are depolarised this is called the QRS complex
What is the significance of AV delay?
It allows atria complete their contraction and force all blood into ventricles. Also I think it ensures that the electrical signal travels down to the apex at once so that all the the myocardial contractile cells in the ventricle depolarize in a short time so that they contract insync.
Does a neuron depolarize or hyperpolarize while you sleep?
Hyperpolarize
What do node cells of the heart depolarize?
purkinje fibers
Does Valium depolarize or hyperpolarize a cell?
Yes it has a depolarizing effect.
Is the left ventricle the first to depolarize?
No, the right ventricle is first to depolarize, that is if you're talking about ventricular depolarization (the QRS complex). If not, then it's the right atrium (atrial depolarization, P wave).
What happen after depolarization of the ventricles?
The ventricles contract.
Actual pumps of the heart?
Ventricles.
Lower chamber of the heart is called?
the lower heart.
