Brain and spinal cord are wrapped in three membranes, called meninges , that are filled with cerebrospinal fluid that cushions and protects. Cerebrospinal fluid is also found within the central canal of spinal cord and ventricles of brain. Neuroglial Cells Are Versatile a. Spinal Cord Communicates a. Functions as center for reflex actions. Communicates between brain and spinal nerves.
Tracts cross over so that left side of brain controls right side of body.
Brain has four cavities or ventricles. Brain stem consists of medulla oblongata, pons, and midbrain. The midbrain also is a relay center for tracts and has reflex centers for head movements in response to visual, auditory, and tactile stimuli. The diencephalon consists of the hypothalamus and thalamus. Functions in muscle coordination, muscle tone, and to maintain posture and balance.