Friday, December 11, 2009

Prof. Noriah's note (2)

Spinal cord


Tract: is a bundle of myelinated nerve fibers located in the CNS (brain + spinal cord).

Sensory (ascending tract) consist of fibers that carry impulse up the spinal cord to different region of the brain.

Motor (descending) tracts - nerve fibers that carry impulses down the spinal cord.

Pathway: is the route followed by a nerve impulse as it travel through the nervous system

In sensory pathway:
Sensory receptor → sensory neuron into spinal cord → travels up the spinal cord by way of sensory (ascending) tract → brain

In motor pathway:
Impulse starts in the brain → travel down the spinal cord by motor (descending) tract → exit spinal cord by way of motor nerve → ends of a muscle/gland