Conducting System Of Heart

Question 1

Situated in right atrium close to opening of superior vena cava

Contains ______ and few myofilaments

The primary pacemaker that generate impulse transmitred in conducting system

The AP generated here are of ________ response type.

Answer 1

SA Node;
Pacemaker cells (P-cells)
Slow

Question 2

SA node

Because of this cell, diff parts of conducting system produce spontaneous beats (automaticity)

From SA node, a conducting tract arises, directly enters into ____ atrium called interatrial tract or ____________

Answer 2

P-cells;
Left atrium, Bachman’s bundle

Question 3

3 internodal pathway that connects SA node and AV node:

Anterior tract of _______
Middle tract of ________
Posterior tract of ________

Velocity of conduction of impulse is 1 m/s

Answer 3

Bachman;
Wenckebach;
Thorel;

Question 4

Is siuated lower part of right atrium close to the ineratrial septum

The rate of impulse conduction is _______

Delay of 0.1 occurs for the impulse to be transmitted through AV node called ______

Answer 4

AV node;
Slow;
AV nodal delay

Question 5

AV node

Ability of AV node to slow down the transmission of rapid impulse from SA node to ventricle

This delay ensures that the _____ have ejected their blood into ______ first before ventricles contract.

Answer 5

Decremental conduction
Atria, ventricles

Question 6

AV node

Delay is shortened by _______ stimulation and lengthened by ________ stimulatiom to the heart.

Answer 6

Sympathetic, parasympathetic

Question 7

Arises from the AV node, about 1 cm in length, which on entering the
interventricular septum divides into right and left bundle branches and terminates in the ________

Cause conduction further delay of _______ secs

Answer 7

His bundle; Purkinje system;
0.04 secs;

Question 8

Bundle Branches

1. _______ is longer and thinner than the left bundle branch, it exclusively innervates the ______ ventricle.
2. ________ bifurcates into two divisions: the ______ division that supplies the anterior portion of the left ventricle, and the ______ division that supplies the posterolateral portion of the left ventricle

Answer 8

1. Right bundle branch (RBB), right ventricle
2. Left bundle branch (LBB), anterior, posterior

Question 9

Present throughout the sub-endocardial regions of right and left ventricle

The cells are the largest cells in the heart.

Numerous ________ (low-impedance electrical synapses) are present between the cells.

Because of the large fiber diameter and low-impedance electrical
synapses, the rate of impulse conduction is highest (almost _______).

Answer 9

Purkinje Fibers;
gap junctions;
4 m/s