Circulatory and Respiratory Systems

Front

Circulatory System Noun

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[sur-kyuh-luh-tawr-ee sis-tuhm]

Back

Circulatory System

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The organ system that delivers oxygen, nutrients, and hormones throughout the body and removes waste products.

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Example: This diagram shows the circulatory system, a network of blood vessels powered by the heart that transports blood to all parts of the body.

Front

Respiratory System Noun

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[res-per-uh-tawr-ee sis-tuhm]

Back

Respiratory System

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The organ system that brings oxygen into the body and releases carbon dioxide into the atmosphere.

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Example: This diagram shows the main parts of the human respiratory system, including the lungs, and a close-up of the alveoli where gas exchange occurs.

Front

Respiration Noun

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[res-puh-rey-shuhn]

Back

Respiration

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The exchange of gases between the body and the outside air, bringing oxygen to cells for energy production.

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Example: This diagram shows gas exchange in the lungs: oxygen from inhaled air passes into red blood cells, and carbon dioxide waste passes out of the blood.

Front

Breathing Noun

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[bree-thing]

Back

Breathing

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The physical process of bringing air into the lungs (inhalation) and expelling air from the lungs (exhalation).

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Example: This diagram shows the process of breathing by comparing inhaling and exhaling, illustrating how the diaphragm's movement causes air to enter and leave the lungs.

Front

Pharynx Noun

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[far-ingks]

Back

Pharynx

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The part of the throat behind the mouth and nasal cavity, serving as a passageway for both food and air.

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Example: This diagram shows the pharynx, the tube behind the nose and mouth, and how it connects to the nasal cavity, oral cavity, and trachea.

Front

Epiglottis Noun

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[ep-i-glot-is]

Back

Epiglottis

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A flap of cartilage that covers the windpipe's opening during swallowing to prevent food from entering the airway.

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Example: This diagram shows the epiglottis, a flap in the throat. It opens to let air into the trachea (windpipe) and closes to block food from entering.

Front

Larynx Noun

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[lar-ingks]

Back

Larynx

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The hollow muscular organ forming an air passage to the lungs and holding the vocal cords; the voice box.

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Example: This diagram shows the larynx (voice box) in the throat, which contains vocal cords that open for breathing and close to produce sound.

Front

Trachea Noun

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[trey-kee-uh]

Back

Trachea

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A long tube, also called the windpipe, that leads from the larynx to the chest and branches into bronchi.

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Example: This diagram shows the trachea, or windpipe, as the tube that carries air from the larynx down to the lungs, separate from the esophagus which carries food.

Front

Bronchus Noun

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[brong-kuhs]

Back

Bronchus

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One of two main tubes that branch from the trachea and serve as the primary passageways into the lungs.

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Example: This diagram shows the trachea (windpipe) splitting into the primary bronchi, the main airways that branch into smaller tubes to carry air into the lungs.

Front

Bronchiole Noun

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[brong-kee-ohl]

Back

Bronchiole

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Any of the minute branches into which a bronchus divides inside the lungs, leading to the alveoli.

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Example: This diagram shows bronchioles as the smaller branching airways inside the lungs, connecting the larger bronchus to the tiny alveoli where gas exchange occurs.