Heart Anatomy and Function

Flashcards covering heart anatomy, function, and related medical conditions.

Heart Location

Located in the central compartment of the thoracic cavity, behind the breastbone, extending more to the left side of the chest cavity.

Heart Chambers

Consists of four chambers: two thin-walled atria (right and left) and two thick-walled ventricles (right and left).

Right Heart

Refers to the right atrium and right ventricle together.

Left Heart

Refers to the left atrium and left ventricle together.

Fibrous Rings

Fibrous connective tissue that separates the atria from the ventricles, acting as an electrical insulator and a skeleton for muscle attachment and cardiac valve insertion.

Endocardium

Endothelial cells covering the inner surface of the heart.

Myocardium

The cardiac muscle, the medium part of the heart wall; ventricles have thicker myocardium than atria, and the left heart has a thicker myocardium than the right heart.

Pericardium

A thin double-layered sac that encloses the heart, consisting of the outermost fibrous pericardium and the inner serous pericardium.

Pericardial Cavity

A space between the layers of the serous pericardium, filled with a small amount of fluid.

Atrioventricular Valves

Valves between the atria and ventricles, including the tricuspid valve (right atrium and right ventricle) and the bicuspid (mitral) valve (left atrium and left ventricle).

Semilunar Valves

Valves between the ventricles and major arteries, including the pulmonary valve (right ventricle and pulmonary artery) and the aortic valve (left ventricle and aorta).

Vena Cava Superior

A systemic vein that carries deoxygenated blood from the upper half of the body to the right atrium.

Vena Cava Inferior

A systemic vein that carries deoxygenated blood from the lower half of the body to the right atrium.

Pulmonary Trunk

An artery of the pulmonary circuit that carries deoxygenated blood from the right ventricle to the lungs, dividing into the right and left pulmonary arteries.

Pulmonary Veins

Veins of the pulmonary circuit that carry oxygenated blood from the lungs to the left atrium.

Aorta

An artery of the systemic circuit that carries oxygenated blood from the left ventricle to all tissues of the body.

SA Node

The sinoatrial node (SA node) – a natural pacemaker that is responsible for the rate and timing of the heartbeat.

AV Node

The AV node acts as a gatekeeper, limiting the electrical activity that reaches the ventricles of the heart.

Systole

The contraction phase of the cardiac cycle.

Diastole

The relaxation phase of the cardiac cycle.

Heart Sounds

Sounds produced by the closing of heart valves; the first sound is created by closing AV valves during systole (systolic sound), and the second sound is produced by closing semilunar valves during diastole (diastolic sound).

Heart Murmur

An abnormal sound produced when blood flows through a defective valve.

Resting Heart Rate

Normal sinus rhythm is approximately 70 beats/minute.

Stroke Volume

The volume of blood pumped from the ventricle during one cardiac cycle at rest, approximately 70 mL.

Cardiac Output

Volume of blood being pumped by the heart during one minute at rest, approximately 5 L/minute.

Holter Monitoring

The diagnostic technique that records ECG for 24 hour or more.

Heart Attack

Blood flow to a part of the heart stops due to a sudden occlusion of a coronary artery; the resulting myocardial damage causes chest pain or death.

Angina Pectoris

Short severe constricting pain deep to the breastbone (sternum) may be felt – angina pectoris.

Arrhythmia

It is a condition when the electrical impulses that coordinate the heartbeats do not work properly.