4.3 Physiology of the Cardiovascular System Part 3 Flashcards
What is heart rate?
number of beats per minute
What are the two main neurotransmitters that help regulate heart rate?
norepinephrine
acetylcholine
Where do the electrical impulses of the heart begin?
sinoatrial node
Where is the SA node?
right atrium
What is known as the pacemaker of the heart?
SA node
What is the SA node?
small mass of specialized cardiac muscle that contains cardiac and nervous tissue characteristics
What happens once the electrical impulse is started at the SA node?
spreads throughout the atria creating the left and right atrial systole
Where does the electrical impulse travel after the atria?
AV node
What is the AV node also known as?
bundle of His
Where does the impulse travel after the AV node?
towards the ventricular apex (down point of the heart)
Where does the electrical impulse travel after the ventricular apex?
purkinje fibers causing the left and right ventricles to contract
What is an EKG?
electrocardiogram
What is the purpose of an EKG?
device used to measure electrical impulses in the heart
What is atrial depolarization?
active firing of a nerve impulse
What is detonated by the P wave on the EKG?
atrial depolarization and atrial systole
What is represented by the QRS complex of an EKG?
ventricular depolarization and ventricular systole
What is denoted by the T wave on an EKG?
ventricular diastole and ventricular repolarization
Is there a way to note atrial repolarization on an EKG?
no; it is lost in the QRS wave
