Cardiac Anatomy and Physiology Flashcards

Vocabulary-style flashcards covering cardiac anatomy, the conduction system, and the cardiac cycle based on the lecture transcript.

Electrocardiogram (ECG)

A recording of electrical changes occurring in the myocardium during the cardiac cycle.

Polarized

The state of cardiac muscle fibers between cardiac cycles where no detectable electrical changes occur.

AV node

Structure located in the inferior portion of the interatrial septum.

SA node

The structure that normally serves as the pacemaker of the heart.

Tachycardia

A rapid heartbeat.

Bradycardia

A slow heartbeat.

T wave

The wave on an ECG that corresponds to repolarization of the muscle fibers of the ventricles.

Chordae tendineae

Fibrous cords that, along with papillary muscles, prevent the cusps of the atrioventricular valves from swinging into the atria.

Papillary muscles

The muscle structures from which chordae tendineae originate.

Tricuspid valve

The valve that prevents blood movement from the right ventricle into the right atrium.

Pericardial sac

The membranes surrounding the heart.

Mitral valve

The valve that prevents blood movement from the left ventricle into the left atrium.

Pulmonary trunk

The vessel that gives rise to the left and right pulmonary arteries; it has a thinner wall related to the lower pressure of the right ventricle.

Coronary sinus

The structure that drains blood from the myocardium into the right atrium.

Endocardium

The inner lining of the heart chambers.

Myocardium

The layer of the heart wall largely composed of cardiac muscle tissue.

Pericardial cavity

The space containing serous fluid to reduce friction during heartbeats.

Cardiac vein

The vessel that drains blood from the myocardial capillaries.

Coronary artery

The vessel that supplies blood to the heart muscle.

Aorta

The vessel that distributes blood to body organs in the systemic circuit (except lungs) and withstands higher pressure due to its thicker wall.

Diastole

The period during which a heart chamber is relaxing.

Systole

The period during which a heart chamber is contracting.

Atrial filling

About $70\,\%$ of the blood from the atria passes into the ventricles before the atrial walls contract.

P wave

The wave on an ECG that corresponds to depolarization of the muscle fibers of the atria.

Apex

The inferior, rounded end of the heart.

Purkinje fibers

Fibers of the conduction system that carry cardiac impulses from the interventricular septum into the myocardium.

QRS complex

The portion of an ECG that corresponds to depolarization of the muscle fibers of the ventricles.

Murmur

The sound created when blood leaks back through an incompletely closed valve.

PQ (PR) interval

Indicates the time it takes for the atria to depolarize and the cardiac impulse to reach the AV node.

Heart sounds

Vibrations in heart tissues created by changes in blood flow, specifically the closing of valves.