Blood

Definition

Blood is a vital fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. It is composed of blood cells suspended in blood plasma.

Related terms

Plasma:

The liquid component of blood in which blood cells are suspended, containing water, proteins, and dissolved substances.

Hemoglobin:

A protein in red blood cells responsible for transporting oxygen from the lungs to the rest of the body.

Leukocytes:

White blood cells involved in protecting the body against both infectious disease and foreign invaders