Cardiac Cycle Flashcards
Where is the apex located ?
Beside the chest wall in the 5th intercostal space midclavicular line
What causes a delay between atria and ventricles depolarisation?
AV node
What are the names of the 3 internodal tracts from the SA node?
Anterior internodal tract of Bachman, middle internodal tract of Wenckebach and posterior internodal tract of Thorell
What are the names given when the heart beats and relaxes?
Systole - beats
Diastole - relaxes
How are atria separated from ventricles ?
One way valves
What is the name of the wave associated with the 3 main pathways from the SA node?
P wave
What is an ECG?
A reading of the electrical activity of the heart and due to the body being mostly compressed of water, any electrical charge developed in the heart can be detected by placing electrodes on the surface of the skin.
Where do the ventricles begin to become depolarised?
Starting at the interventricular septum on the LHS then turning right.
What does the QRS complex show us?
Shows us the the ventricles have been activated to contract and that they have been depolarised.
How is repolarisation of the ventricles noticed on an ECG?
T wave
When you breath in your heart rate goes ________ and when you breath out your heart rate goes ________.
Up
Down
Why does hr increase when we breath in.
When the lungs inflate, they cause the vagus nerve to turn off and this nerve is what causes the hr to decrease.
What causes Stokes Adams syndrome?
Atria contract at a much faster rate than the ventricles and a patient with Stokes Adams syndrome cannot get up without passing out as the pumping is so inefficient.
What is an Ectopic foci?
When a part of the heart which doesn’t normally give off a beat generated an electrical signal which travels through the heart and can render that part of the heart refractory or disrupt the signal.
It can cause an extra systole.
What is re-entry phenomena ?
Signals going from ventricles to atria and it causes electrical activation that is uncontrolled and can cause many problems.