8/12/2019 Complete List of Terms and Definitions for Conduction System of the Heart

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Complete List of Terms and Definitions forConduction System of the Heart

Terms Definitions

AV Node Atrialventricular node: receives signal from SA node; at junction

of atria and ventricles

*if SA node damaged, AV node can take over as pacemaker, but a

a slower rate

6 Here in the Ventricles Conduction Myofibrils gather and distribut

the impulses into the myocardium of the Ventricles

P wave depolarization (contraction) of the atria

atrioventricular node transfers nerve impulses to the atrioventricular bundal.

1 Muscle Impulses are generated at the Sinoatrial Node

Bundle branches Conduct impulses down both sides of the interventricular septum

5 Here the Impulses are split apart from the Atrioventricular Bundle

into two paths towards the Left and Right Ventricles

sinoatrial node Acts as the pacemaker for the entire heart

Systems that control the heart 1. Autonomic Nervous System

2. Intrinsic Conduction System

bundle of His a tract of conduction fibers composed of a right and left branch,

relays the impulse from the AV node to the Purkinje fibers

WHERE ARE THE CHEMORECEPTORS LOCATED AND

WHAT DO THEY MONITOR?

CAROTID ARTERY/LEVELS OF O2 & CO2

WHAT DOES THE SYMPATHETIC INPUT CAUSE IN THE

HEART?

INCREASED HR AND FORCE OF CONTRACTION

4 Traveling down the Atrioventricular Bundles they reach the

Interventricular Septum

THE BARORECEPTORS DECREASED BP STIMUALTED

WHAT SYSTEM TO DO WHAT?

SYMPATHETIC/INCREASE HR

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T wave repolarization (recovery) of the ventricles

Purkinje fibers (network) Distribute the electrical impulses through the right and left

ventricles

WHAT INITIATES IMPULSES THAT CAUSE VENTRICLES

TO CONTRACT SIMULTANEOUSLY?

AV NODE

Atrioventricular bundle [AV bundle]; a bundle of modified heart muscle that transmits the

cardiac impulse from the atrioventricular node to the ventricles

causing them to contract

WHAT IS THE CONTROL CENTER FOR AUTONOMIC

INPUT TO THE HEART?

BRAINSTEM/MEDULLA OBLONGATA

Factors Affecting heart Rate Resting rate: Males 64-72 bpm. Females: 72-80 bpm. Epinephrine

increases heart rate (vasoconstrictor). Calcium-high levels increas

heart rate. Potassium-high levels lower heart rate.

Specialized functions of cardiac muscle cells 1. Contract spontaneously and independently

2. Intercalated disks: help spontaneous contractions occur (action

potentials; synchronize contraction of myocardium)

2. Myocytes in different areas of heart have different rhythms

WHERE IS THE AV NODE LOCATED? BETWEEN THE RA AND RV

WHERE IS THE SA NODE LOCATED? IN THE WALL OF THE RA

Sinoatrial (SA) node (pacemaker) Initiates heart at a rate of 60 to 100 beats per minute with electrica

impulse that causes depolarization

2 Impulses travel to the Atrioventricular Node

THE BARORECEPTORS INCREASED BP STIMULATED

WHAT SYSTEM TO DO WHAT?

PARASYMPATHETIC/DECREASE HR

Purkinje fibers Carries nerve impulses upward through the walls of the ventricles,

WHAT IS THE HEART'S PACEMAKER: INITIATES

IMPULSES THAT CAUSE ATRIA TO CONTRACT

SIMULTANEOUSLY?

SA NODE

DECREASED O2 OR INCREASED CO2 LEAD TO

INCREASED HR AND RR BECAUSE OF WHAT TYPE OF

RECEPTOR?

CHEMORECEPTOR

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EKGs: what they measure, how the measure Measure flow of current throughout heart

Heart impulses are detected on surface of body

WHERE ARE THE BARORECPTORS LOCATED AND WHAT

DO THEY MONITOR?

IN THE AORTA AND CAROTID ARTERY AND THEY

MONITOR BLOOD PRESSURE.