Human Body Systems

Circulatory System

MCAT Anatomy > Human Body Systems > Circulatory System

Background

Circulation

See Circulation

Blood

See Blood

Blood Vessels

See Blood Vessels

Arteries

See Arteries

Veins

See Veins

Capillaries

See Capillaries

Gas Transport

See Gas Transport

Nutrient Transport

See Nutrient Transport

Carbohydrates and amino acids are absorbed into the small intestine via capillaries in the villi, and enter systemic circulation via the hepatic portal system

Fats are absorbed by the lacteals in the small intestine and bypass the hepatic portal system and directly enter systemic circulation via the thoracic duct. Fats are packaged as lipoproteins, which are water-soluble molecules

Waste Transport

See Waste Transport

Wastes such as carbon dioxide, ammonia (NH2) and urea, enter the blood stream throughout the body as they travel down concentration gradients from the tissues to the capillaries. Blood eventually passes through the excretory organs such as the kidneys, and where waste products are filtered and excreted through urination or ventilation.

Blood Clotting

See Blood Clotting

Concentration Gradients

See Concentration Gradients

The Heart

See The Heart

Circulatory System

Circulatory System Links

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