40B - Lab - Exercise #28

Question 1

Sinoatrial (SA) Node

Answer 1

S for START
Pacemaker
Initiates action potential first; stimulates atria to contract.
Located in the wall of right atrium

Question 2

Atrioventicular (AV) Node

Answer 2

Receives action potential from atrial muscle fibers.
Sends action potentials to AV bundle
Located in interatrial septum

Question 3

AV Bundle

Answer 3

Located in septum between atria and ventricles.

Electrial connection between atria and ventricle; sends action potential to bundle branches

Question 4

Right and Left Bundle Branches

Answer 4

Located in interventricular septum

Sends action potential to Purkije fibers

Question 5

Purkinje Fibers

Answer 5

Located in apex

Send action potential to ventricular mucles and papillary muscles to contract

Question 6

What does an ECG / EKG represent?

Answer 6

Conduction System

Question 7

How is the information from an ECG / EKG used?

Answer 7

Diagnostically

Question 8

P Wave

Answer 8

First Wave

Represents atrial depolarization that spreads from the SA node before atrial contracts

Question 9

QRS Wave

Answer 9

Represents ventricular depolarization that spreads from AV node, AV bundle, right and left bundle branches, and purkinje fibers betfore ventricles contract

Question 10

T Wave

Answer 10

Last Wave

Represents ventricular repolarizationand occurs just before the ventricles relax

Question 11

What takes place during the QRS complex, but not observed on the ECG / EKG?

Answer 11

Atrial repolarization

Question 12

Bradycardia

Answer 12

Heart rate 50 - 60 BPM at REST

Question 13

Normal Heart rate

Answer 13

~75 BPM

Question 14

Tachycardia

Answer 14

Heart rate above 100 BPM at REST

Question 15

Conduction system

Answer 15

1. Initiates action potential to contract muscle fibers

2. Provides a pathway for action potential to all of cardiac fibers