Harvard Human Anatomy - Vessels & Circulation

Circulatory system: The main function of this body system is transporting and distributing gases, nutrients, and waste products of metabolism.

Blood vascular system: The part of the circulatory system comprising a fluid (blood), a muscular pump (heart), and a network of vessels.

Lymph vascular system: The part of the circulatory system comprising a fluid (lymph) and a network of capillaries and vessels including nodes.

Blood: Consists of hematocytes and platelets suspended in plasma.

Hematocrit: The percentage of whole blood volume made up of blood cells (hematocytes).

Erythrocytes: Red blood cells that transport gases (45% of the hematocrit).

Buffy coat: Consists of leukocytes and platelets (<1% of hematocrit).

Plasma: A fluid consisting of water, plasma proteins, and solutes.

Plasmacrit: Percentage of plasma represented in a sample.

Heart: In humans, a four-chambered muscular pump that propels blood through the vessels of the circulatory system. It can be divided into the right atrium, right ventricle, left atrium, and left ventricle.

Artery: A blood vessel that carries blood away from the heart toward tissues.

Vein: A blood vessel that carries blood toward the heart from the tissue capillary beds. 

Pulmonary circulation: The process through which the heart receives deoxygenated blood from the body and pumps it to the lungs.

Systemic circulation: The process through which the heart receives oxygenated blood from the lungs and pumps it to the body.

Pulmonary arteries: Arteries that carry blood to capillary beds in the lungs.

Pulmonary veins: Veins that carry oxygenated blood from capillary beds in the lungs toward the heart.

Aorta: An artery that carries blood from the heart to the extensive arterial network that ends in capillary beds in the body.

Superior vena cava: A vein that carries deoxygenated blood from the upper half of the body to the right atrium of the heart.

Inferior vena cava: A large vein that carries deoxygenated blood from the lower half of the body to the right atrium of the heart.

Portal vein: Carries nutrient-rich blood from the gastrointestinal tract to the liver.

Mitral valve: Separates the left atrium and the left ventricle.

Tricuspid valve: Separates the right atrium from the right ventricle.