Circulatory System Terminology

Cardiovascular system

The heart and blood vessels responsible for circulating blood throughout the body.

Atrium

An upper chamber of the heart that receives blood.

Ventricle

A lower chamber of the heart that pumps blood out of the heart.

Septum

The wall separating the left and right sides of the heart.

Aorta

The largest artery; carries oxygenated blood from the left ventricle to the body.

Superior vena cava

A large vein carrying deoxygenated blood from the upper body to the right atrium.

Inferior vena cava

A large vein carrying deoxygenated blood from the lower body to the right atrium.

Pulmonary artery

The artery carrying deoxygenated blood from the right ventricle to the lungs.

Pulmonary veins

Veins carrying oxygenated blood from the lungs to the left atrium.

Coronary arteries

Arteries supplying blood to the heart muscle.

Tricuspid valve

The valve between the right atrium and right ventricle.

Mitral valve

The valve between the left atrium and left ventricle.

Aortic valve

The valve between the left ventricle and aorta.

Pulmonary valve

The valve between the right ventricle and pulmonary artery.

Systole

The contraction phase of the heart.

Diastole

The relaxation/filling phase of the heart.

Cardiac output

The amount of blood pumped by the heart per minute.

Stroke volume

The amount of blood ejected by a ventricle with each heartbeat.

Heart rate

The number of heartbeats per minute.

Blood pressure

The force of blood against the walls of blood vessels.

Hypertension

Abnormally high blood pressure.

Hypotension

Abnormally low blood pressure.

Bradycardia

An abnormally slow heart rate.

Tachycardia

An abnormally fast heart rate.

Arrhythmia

An abnormal heart rhythm.

Atherosclerosis

Buildup of fatty plaques within artery walls.

Arteriosclerosis

Thickening and hardening of artery walls.

Coronary artery disease (CAD)

Narrowing or blockage of coronary arteries, usually from atherosclerosis.

Angina

Chest pain or discomfort caused by inadequate blood flow to heart muscle.

Myocardial infarction (MI)

A heart attack caused by interruption of blood flow to heart muscle.

Heart failure

A condition in which the heart cannot pump enough blood to meet the body's needs.

Cardiomyopathy

Disease of the heart muscle that affects its ability to pump.

Endocarditis

Inflammation or infection of the inner lining of the heart, often involving valves.

Pericarditis

Inflammation of the sac surrounding the heart.

Myocarditis

Inflammation of the heart muscle.

Aneurysm

A weakened area of a blood vessel wall that bulges outward.

Thrombosis

Formation of a blood clot inside a blood vessel.

Embolus

A traveling clot or other material that blocks a blood vessel.

Embolism

Blockage of a blood vessel by an embolus.

Deep vein thrombosis (DVT)

A blood clot in a deep vein, usually in the leg.

Pulmonary embolism

A blockage of a pulmonary artery, commonly caused by a blood clot traveling from a DVT.

Varicose veins

Enlarged, twisted veins caused by weakened or faulty valves.

Anemia

A condition in which the blood has reduced oxygen-carrying capacity, commonly due to low hemoglobin or red blood cells.

Leukemia

Cancer of blood-forming tissues characterized by abnormal blood cells.

Hemophilia

An inherited bleeding disorder caused by deficiency of certain clotting factors.

Thrombocytopenia

Abnormally low platelet count.

Hematoma

A localized collection of blood outside blood vessels.

Hemoglobin

The oxygen-carrying protein in red blood cells.

Erythrocyte

A red blood cell.

Leukocyte

A white blood cell.

Platelet

A cell fragment involved in blood clotting.

Plasma

The liquid portion of blood.

Hemostasis

The process that stops bleeding.

Coagulation

The process of forming a blood clot.

Electrocardiogram (ECG/EKG)

A recording of the heart's electrical activity.