Neurones and Sinapse

Neuron

Millions of cells in the nervous system are also known as nerve cells

The basic structure of neuron

Consists of a cell body, axon, dendrite, myelin sheath, a node of Ranvier and a synaptic knob

Three types of neurone

Sensory neurones, relay neurones and motor neurones

Dendrite

Short branches of the cell body. Dendrite receives nerve impulses from other neurones or the external environment and sends them to the cell body

Axon

Elongated branch of the body cell, axon carries impulses out of the cell body to other neurones or effectors.

Mielin sheath

Insulating membrane that coats the axon

Cell body

Consists of a nucleus and many cytoplasmic projections called dendrites.

Synaptic knob

Swelling at the end of the axon branch

Node of ranvier

The gaps portion of the neuron that is not wrapped by the myelin sheath along the axon

Importance node of Ranvier

Helps to accelerate the flow of nerve impulses by allowing the nerve impulses to jump from one node to the following node