Circulatory System

Front

Circulatory System Noun

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[sur-kyuh-luh-taw-ree sis-tuhm]

Back

Circulatory System

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The organ system responsible for transporting blood, oxygen, and nutrients throughout the body, consisting of the heart and blood vessels.

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Example: This image shows the circulatory system as a network of blood vessels (arteries in red, veins in blue) that transports blood throughout the entire body, powered by the central heart.

Front

Atrium Noun

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[ey-tree-uhm]

Back

Atrium

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An upper chamber of the heart that receives blood returning to the heart from either the body or the lungs.

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Example: This diagram shows the heart's two upper chambers, the right and left atrium, which receive blood before it passes to the ventricles below.

Front

Ventricle Noun

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[ven-tri-kuhl]

Back

Ventricle

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A lower, thick-walled chamber of the heart that pumps blood out to the lungs or the rest of the body.

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Example: This diagram shows the heart's four chambers, highlighting the two lower chambers, the right and left ventricles, which pump blood out of the heart.

Front

Septum Noun

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[sep-tuhm]

Back

Septum

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The muscular wall dividing the right and left sides of the heart, preventing the mixing of different blood types.

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Example: The septum is the thick muscular wall that divides the right and left sides of the heart, keeping oxygen-rich and oxygen-poor blood separate.

Front

Pacemaker Noun

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[peys-mey-ker]

Back

Pacemaker

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A specialized group of muscle cells in the right atrium that controls the heart's rhythm by generating electrical impulses.

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Example: This diagram shows the heart's natural pacemaker, the Sinoatrial (SA) node, and the electrical pathways that signal the heart muscles to contract and pump blood.

Front

Pulmonary Circulation Noun

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[puhl-muh-ner-ee sur-kyuh-ley-shuhn]

Back

Pulmonary Circulation

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The circuit that carries deoxygenated blood from the heart to the lungs and returns oxygenated blood back to the heart.

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Example: This diagram shows how the heart pumps blue, deoxygenated blood to the lungs via the pulmonary artery, and receives red, oxygenated blood back via the pulmonary vein.

Front

Systemic Circulation Noun

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[si-stem-ik sur-kyuh-ley-shuhn]

Back

Systemic Circulation

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The circuit that carries oxygenated blood from the heart to the rest of the body and returns deoxygenated blood.

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Example: This diagram shows systemic circulation as the path where oxygen-rich blood (red) is pumped from the heart to the body's capillaries and back.

Front

Artery Noun

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[ahr-tuh-ree]

Back

Artery

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A blood vessel with thick, elastic walls that carries blood away from the heart, typically under high pressure.

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Example: This image shows a cross-section of an artery, revealing its thick, muscular, and elastic walls, which are built to withstand high-pressure blood flow from the heart.

Front

Vein Noun

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[veyn]

Back

Vein

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A blood vessel that carries blood towards the heart, often containing valves to prevent the backflow of blood.

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Example: This diagram shows veins (blue) as the blood vessels that carry deoxygenated blood from all over the body back towards the heart.

Front

Capillary Noun

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[kap-uh-ler-ee]

Back

Capillary

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The smallest blood vessel where the exchange of gases, nutrients, and waste occurs between blood and the body's tissues.

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Example: This diagram shows a capillary, a tiny blood vessel, wrapped around an air sac in the lung, where oxygen enters the blood and carbon dioxide leaves.