Human Physiology

Lesson 40 : Organization of Nervous System

Definitions

Nerve: is a group of nerve fibers outside CNS e.g. brachial nerve.

Tract: is a group of nerve fibers inside CNS e.g. spinothalamic tract.

Nucleus: is a group of nerve cell bodies inside CNS e.g. supra optic nucleus.

Ganglion: is a group of nerve cell bodies outside CNS e.g. coeliac ganglion.

Synapse: is a junction of two neurons e.g. axo-somatic, axo-dendritic or axo-axonal synapse.

Sensory nerve: is afferent nerve carrying nervous impulse from peripheral organ towards CNS e.g. optic nerve.

Motor nerve: efferent nerve carrying nervous impulse from CNS to peripheral organ e.g. & occulomotor nerve.

Neurotransmitters: are chemical messengers released from one neuron and act on next neuron ; across a synapse to transmit nerve impulse e.g. acetylcholine, nor-epinephrine.