___________-muscle that reverses, or opposes, the action of another muscle

________________-a dark brown to black pigment formed by cells called melanocytes occurring in the hair, skin, and iris of the eye in people and animals; responsible for tanning of skin exposed to sunlight

____________-a specialized cell that transmits electrical signals; a nerve cell

__________-white substance of the central nervous system; myelinated nervous fibers

________-mature cartilage cell

___________-the bundle of nervous tissue that runs from the brain to the lumbar vertebrae and provides a conduction pathway to and from the brain

_________________________________ -a state of body equilibrium or stable internal environment of the body

Identify and click on the rectus femoris.

______________-neuron process that carries impulses away from the nerve cell body; efferent process; the conducting portion of the nerve cell

_________________________________ -relating to the limbs; one of the two major divisions of the body