Cardiac Physiology and Electrocardiogram

These flashcards cover key concepts related to cardiac physiology, including the function of pacemaker nodes, nervous system influences on heart rate, and components of an electrocardiogram.

SA Node

The primary pacemaker of the heart located in the right atrium.

AV Node

The secondary pacemaker of the heart that receives impulses from the SA node and conducts them to the ventricles.

Purkinje Fibers

The tertiary pacemaker of the heart that conducts impulses through the ventricles.

Threshold Point

The level of depolarization necessary to trigger action potentials in cardiac cells.

Sympathetic Nervous System

The part of the autonomic nervous system that increases heart rate and prepares the body for 'fight or flight'.

Parasympathetic Nervous System

The part of the autonomic nervous system that slows the heart rate and promotes a state of rest.

Einthoven's Triangle

A triangle formed by the placement of electrodes on the body to measure electrical activity of the heart.

Electrocardiogram (EKG/ECG)

A test that measures the electrical activity of the heart over a period of time.

P Wave

Represents atrial depolarization in an EKG.

QRS Complex

Represents ventricular depolarization in an EKG.

T Wave

Represents ventricular repolarization in an EKG.