to breakdown & absorb nutrients that are necessary for growth & maintenance.
to filter our cellular wastes, toxins, & excess water or nutrients from the circulatory system.
to provide gas exchange between the blood & the environment.
to manufacture cells that allow reproduction.
to relay chemical messages through the body.
to relay electrical signals through the body.
to transport nutrients, gases, hormones, and wastes through the body.
to provide movement.
to provide support for the body, to protect delicate internal organs, and to provide attachment sites for the organs.
to provide a protective barrier between the inside of the body & the outside world & to provide sensory information to the brain.