Electrical Impulses

Question 1

function of electrical impulses

Answer 1

maintain heart’s intrinsic rhythmic ability

Question 2

where cardiac muscle contractions begin

Answer 2

in heart (independent of CNS

Question 3

heart rate (beats per minute) regulated via

Answer 3

nervous system and endocrine systems (including neurotransmitters norepinephrine and ACh)
–> allows heart to change BP based on physical and emotional stressors

Question 4

where electrical impulse begins

Answer 4

sinoatrial (SA) node

Question 5

SA node

Answer 5

small mass of specialized cardiac muscle in right atrium aka pacemaker of heart (where impulse begins)

Question 6

path of electrical impulse through heart

Answer 6

SA node –> throughout atria (causing L + R atrial systole) –> atrioventricular (AV) node –> bundle of His –> ventricular apex (downward pt of heart) –> Purkinje fibers (causing L + R ventricle systole)

Question 7

EKG

Answer 7

aka ECG, electrocardiogram

device used to monitor heart’s electrical impulses to diagnose patient conditions

Question 8

depolarization

Answer 8

active firing of nerve impulse

Question 9

repolarization

Answer 9

resetting of nerve impulse after firing

Question 10

P-wave measures

Answer 10

atrial depolarization + atrial systole

Question 11

QRS complex measures

Answer 11

ventricular depolarization + ventricular systole

Question 12

T - wave measures

Answer 12

ventricular repolarization + ventricular diastole