components of the neurone

axon

extension of the cytoplasm that transmit impulses away from the cell body to the axon endings

dendrites

many thin extensions of the cytoplasm that receive impulses from other nerve cells and transmit impulses towards the cell body

cell body

contains the nucleus and groups of ribosomes in the cytoplasm that synthesise neurotransmitters

synaptic end bulb

swelling at the end of the axon in which neurotransmitter is stored

axon ending

secretes neurotransmitters by exocytosis into synaptic cleft

schwann cells

surround peripheral neurones in vertebrates and grow around the axon to form a multi layered myelin sheath

myelin sheath

formed as schwann cells grow around the axon in peripheral neurones, provide electrical insulation to speed up nerve impulse transmission

nodes of ranvier

intervals in the myelin sheath between adjacent schwann cells