Heart Anatomy and Cardiac Cycle Lecture Notes

Flashcards covering key vocabulary related to heart anatomy, cardiac cycle, and related functional aspects.

Cardiac Cycle

One complete contraction and relaxation of all four chambers of the heart.

Systole

Contraction phase of a heart chamber.

Diastole

Relaxation (filling) phase of a heart chamber.

Autorhythmicity

The ability of cardiac muscle to initiate electrical activity at a fixed rate.

SA Node

The pacemaker of the heart located in the right atrium.

AV Node

A clump of specialized myocardial conductive cells that slows down impulses to allow atrial contraction.

Electrocardiogram (ECG or EKG)

A recording of the electrical activity of the heart.

End Diastolic Volume (EDV)

Volume of blood in the ventricles just before contraction.

Stroke Volume

The amount of blood pumped by the left ventricle in one contraction, approximately 70-80 mL.

Heart Sounds

Sounds made by the heart as it beats; includes S1 (lub) and S2 (dub) due to valve closures.

Cardiac Output

The volume of blood the heart pumps per minute.

Intercalated Discs

Specialized connections between cardiac muscle cells that synchronize contraction.

Pectinate Muscles

Internal ridges of myocardium in the atria.

Chordae Tendineae

Tendinous cords that connect the AV valves to papillary muscles.

Pulmonary Circuit

Transports blood to and from the lungs to pick up oxygen and remove carbon dioxide.

Systemic Circuit

Transports oxygenated blood to body tissues and receives deoxygenated blood.

Auricles

Thin-walled extensions of the atria.

Septum

Walls that divide the heart into chambers.

Atrioventricular Valves

Valves located between atria and ventricles that prevent backflow of blood.

Semilunar Valves

Valves that regulate flow out of the heart.

Veins

Blood vessels that carry deoxygenated blood back to the heart.

Arteries

Blood vessels that carry oxygenated blood away from the heart.