14_-_Circulation_and_Gas_exchange

Circulation

The movement of blood throughout the body to supply nutrients and remove waste.

Gas exchange

The process by which oxygen is acquired and carbon dioxide is expelled from an organism.

Gastrovascular cavity

A digestive cavity that also serves for the exchange of gases and nutrients in cnidarians.

Madreporite

A sieve-like structure on the surface of echinoderms that allows water to enter the water vascular system.

Countercurrent exchange

The process that maximizes gas exchange efficiency by having blood flow in the opposite direction to water in the gills.

Hemolymph

The fluid equivalent of blood in invertebrates with an open circulatory system, such as insects.

Boyle's Law

A principle stating that the pressure of a gas is inversely proportional to its volume; used to explain inhalation and exhalation.

Pulmonary circulation

The portion of the circulatory system that carries deoxygenated blood from the heart to the lungs.

Systemic circulation

The part of the cardiovascular system that carries oxygenated blood away from the heart to the body.

Trachea

A tube that carries air to and from the lungs in terrestrial vertebrates, but also serves in insects for gas exchange.

Oxygenated blood

Blood rich in oxygen, typically found in the arteries leading from the lungs to the heart and body.

Deoxygenated blood

Blood that has a lower oxygen content and is typically found in veins carrying blood back to the heart.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs.

Lymphatic system

A system that helps maintain fluid balance in the body by collecting excess tissue fluid and returning it to the bloodstream.

Capillaries

Small blood vessels where the exchange of gases, nutrients, and waste occurs between blood and tissues.

Spiracle

An external opening in insects that leads to the tracheal system for breathing.

Radial canal

Canals in echinoderms that distribute water throughout the body.

Valve

A structure in veins that prevents backflow of blood, ensuring one-way circulation.

Nasal cavity

The hollow space behind the nose that helps warm and filter air as it enters the respiratory system.

Branch of pulmonary vein

Carries oxygen-rich blood from the lungs to the heart.

Gill capillaries

Small blood vessels in gills where oxygen and carbon dioxide are exchanged.