Circulation

Septum

Structure that separates oxygenated and deoxygenated blood in the heart.

Vena cava

Superior and inferior vena cava return deoxygenated blood from the body to the right atrium.

Right atrium

Receives deoxygenated blood from the body.

Right ventricle

Pumps deoxygenated blood to the lungs through the pulmonary artery.

Pulmonary artery

Carries deoxygenated blood from the right ventricle to the lungs.

Pulmonary veins

Carry oxygenated blood from the lungs to the left atrium.

Left atrium

Receives oxygenated blood from the lungs.

Left ventricle

Pumps oxygenated blood to the body through the aorta.

Aorta

Carries oxygenated blood from the left ventricle to the body.

Arteries

Carry blood away from the heart.

Veins

Carry blood toward the heart.

Pulmonary artery exception

Artery that carries deoxygenated blood.

Pulmonary vein exception

Vein that carries oxygenated blood.

Vein valves

Prevent backflow of blood.

Fight-or-flight blood vessels

Arteries to skeletal muscles dilate; arteries to the digestive tract constrict.

Acid precipitation

Caused by sulfur dioxide and nitrogen oxides reacting with water in the atmosphere.

Fertilizer runoff

Causes eutrophication and algal blooms, not acid precipitation.

Geographic isolation

Physical separation of populations by barriers like mountains, rivers, islands, or distance.

Geographic isolation and evolution

Stops gene flow, so populations can evolve differently and form new species.

Speciation

Formation of a new species.

Always true of veins

Veins carry blood toward the heart.