Neurones

The motor neurone controls the contraction of muscle cellls.

• Cell body containing nucleus and other organelles
• Dendrites radiate from the cell body to communicate with other neurones
• A long axon, full of many mitochondria, leads out of the cell body
• The axon is insulated by the myelin sheath
• Myelin sheath consists of a membrane of a Schwann cell, which wraps around a layer of fat surrounding the axon, insulating the axon.
• At intervals there are gaps in the sheath, where impuses are regenerated, which are called nodes of Ranvier
• The axon ends in a number of dendrites which contact muscle tissue with motor end plates

Sensory neurones are similar to motor neurones, with a few differences:

• The neurones transmit messages to the Central Nervoud System
• Each neurone has a receptor, reacting to a certain stimulus (e.g. Temperature)
• The receptor reacts to local change by generating a nervous impulse
• When a stimulus illicits an impulse being created, it is known as a transduction