Conducting System Flashcards
What is the conducting system of the heart composed of?
Modified cardiac muscle fibers
F: SA Node
F: start electrical impulse in the heart, propagates and contracts the atrial walls, and reaches the AV node
L: SA node
right atrium wall, close to superior vena cava opening
F: AV node
F: Gives rise to modified myocardial fibres that receive the impulse from the SA node
L: AV node
right side of interatrial septum close to coronary sinus in the right atrium
F: AV bundle
receive impulse from AV node and carries to Purkinje fibers
L: AV bundle
starts from atrioventricular node, enters interventricular septum, divides into right and left branches
L: Purkinje fibers
distribute into right and left ventricular walls
What else increases the heart rate?
Sympathetic cardiac nerves
What is the source of sympathetic cardiac nerves to the heart?
from thoracic spinal segments
What else decreases the heart rate?
Parasympathetic cardiac nerves
What is the source of parasympathetic cardiac nerves to the heart?
from vagus nerve from the nucleus of vagus in the medulla
What is the path of the electrical impulse in the conducting system of the heart?
a. Start from SA node
b. Propagate through and contract atrial walls
c. Reaches AV node
d. Pass through ventricular walls through AV bundle
e. Pass through Purkinje fibers
f. Ventricles contract
