PHYSCI 5: EKG Lab - Cardiac Anatomy, Conduction, and Rhythms

Vocabulary practice flashcards covering cardiac anatomy, the electrical conduction pathway, EKG waveforms and intervals, heart rate calculation, and normal versus abnormal cardiac rhythms.

Right Atrium and Right Ventricle

The heart chambers that receive deoxygenated blood from the body and pump it to the lungs.

Left Atrium and Left Ventricle

The heart chambers that receive oxygenated blood from the lungs and pump it out to the body.

Left Ventricle

The chamber of the heart with the thickest muscular wall, enabling it to pump blood the farthest distance to the entire body.

Tricuspid Valve

The atrioventricular valve located between the right atrium and the right ventricle that prevents blood from flowing backward.

Bicuspid (Mitral) Valve

The atrioventricular valve situated between the left atrium and the left ventricle.

Semilunar Valves

The valves located at the exit of each ventricle, consisting of the pulmonary valve and aortic valve.

Vena Cavae

The superior and inferior vena cava, which return deoxygenated blood from systemic circulation into the right atrium.

Pulmonary Trunk

The major blood vessel exiting the right ventricle that carries deoxygenated blood toward the lungs.

Pulmonary Veins

Four vessels that carry oxygenated blood from the lungs and empty directly into the left atrium.

Aorta

The primary systemic artery that carries oxygenated blood out of the left ventricle to supply the rest of the body.

Pulmonary Circuit

The circulatory pathway consisting of $\text{right ventricle} \rightarrow \text{lungs} \rightarrow \text{left atrium}$, where deoxygenated blood releases carbon dioxide and picks up oxygen.

Systemic Circuit

The circulatory loop consisting of $\text{left ventricle} \rightarrow \text{body} \rightarrow \text{right atrium}$, delivering oxygenated blood to body tissues.

Sinoatrial (SA) Node

The heart's natural pacemaker located in the right atrium that initiates the electrical impulse for each heartbeat.

Atrioventricular (AV) Node

The electrical conduction structure that briefly delays the incoming impulse from the SA node to allow the atria to finish contracting before ventricular contraction begins.

Bundle of His, Bundle Branches, and Purkinje Fibers

Specialized conductive tissues that rapidly propagate the electrical signal down the septum and throughout both ventricles, producing coordinated ventricular contraction.

Electrocardiogram (EKG)

A diagnostic recording obtained via electrodes placed on the skin that measures and plots the electrical activity of the heart as a repeating waveform.

12-Lead EKG

A standard clinical electrocardiogram setup that records the heart's electrical activity from twelve distinct electrical angles simultaneously.

P Wave

The first deflection on an EKG tracing, representing atrial depolarization (contraction of the atria).

QRS Complex

The prominent EKG waveform representing ventricular depolarization (ventricular contraction), which simultaneously masks atrial repolarization.

T Wave

The deflection on an EKG tracing that represents ventricular repolarization, the electrical recovery phase before the subsequent heartbeat.

PR Interval

The time period measured from the start of the P wave to the beginning of the QRS complex, quantifying the elapsed time between atrial and ventricular depolarization.

QT Interval

The duration spanning from the start of the QRS complex to the termination of the T wave, representing the total time taken for ventricles to depolarize and repolarize.

EKG Segments vs. Intervals

On an EKG strip, segments span exclusively between two waves, whereas intervals comprise a wave in addition to an adjoining segment.

R-R Interval

The time elapsed between two consecutive R wave peaks on an EKG strip, which is inversely proportional to heart rate.

Heart Rate Calculation Formula (EKG)

$$\text{Heart rate (bpm)} = \frac{60}{\text{R-R interval (in seconds)}}$$

Normal Sinus Rhythm

The baseline cardiac rhythm exhibiting normal P-QRS-T complexes, regular spacing, and a rate between $60\text{--}100\,\text{bpm}$.

Bradycardia

A resting heart rate below $60\,\text{bpm}$ with normal and regular P-QRS-T complexes, frequently seen as a healthy, non-pathological adaptation in well-conditioned athletes.

Tachycardia

A resting heart rate greater than $100\,\text{bpm}$ characterized by normal, regular complexes; triggered by factors such as exercise, stress, fever, caffeine, or cardiac conditions.

Arrhythmia

Broadly, any abnormal cardiac rhythm; narrowly used to describe a rhythm displaying normal complexes occurring in an irregular, non-uniform pattern without another definitive diagnosis.

Atrial Fibrillation

An arrhythmia marked by chaotic electrical quivering in the atria, absent P waves, an irregularly irregular ventricular response, and increased stroke risk due to atrial blood pooling.

Ventricular Fibrillation

A life-threatening medical emergency where the ventricles quiver chaotically without effective blood output, manifesting as rapid, wide, irregular complexes that require immediate defibrillation.