Cardiovascular Physiology 8 Flashcards
What is the meaning of the heart contracting in series?
First both atria contract as a unit then both ventricles contract as a unit
Where are Conducting myocytes found?
- Sinoatrial (SA) node
- Internodal pathways
- Atrioventricular (AV) node
- Bundle of HIS (AV) bundle
- Bundle branches (left and right)
- Purkinje fibers
Where is the Sinoatrial node located?
In the wall of the right atrium near the opening of the superior vena cava
Where is the Atrioventricular (AV) node located?
In the base of the right atrium near the interatrial septum
Where does the conducting pathway span?
From the SA node to the AV node crossing the interatrial septum to the left atrium to the bundle of his to the left and right bundle branch to the purkinje fibers
Which part of the conducting system passes the interventricular septum?
The bundle of his
Where do the left and right bundle branches separate?
At the apex of the heart
What is the only electrical connect between the atria and the ventricles?
The bundle of his and the AV node
What is the conducting system composed of?
Myocardial cells
Which conducting myocytes generate action potential the fastest?
Conducting myocytes in the sinoatrial node
What is known as the cardiac pacemaker?
The SA node
Where does the stimulus go once generated by the SA node?
The internodal pathways
Where do the internodal pathways stimulate contraction?
The left and right atria
What are the three places that the SA node sends stimulus?
The two internodal pathways and the atrioventricular AV node
What does the AV nodal delay ensure?
That the atria depolarize and contract before the ventricles depolarize and contract
