Nervous Tissue Organisation

List the basic functions of the nervous system

• Senses information from inside and outside the body

• Processes and understands the information

• Responds by sending signals to muscles or glands

Central Nervous System (CNS)

• Brain and spinal cord

• Processes and controls everything

Peripheral Nervous System (PNS)

• All the nerves outside the brain and spinal cord

• Carries messages to and from the CNS

Schwann Cells

Form myelin sheath around PNS neurons

Oligodendrocytes

Form myelin sheath around CNS neurons

Microglial Cells

Migratory phagocytes of the CNS

Astrocytes

Form part of blood-brain barrier in the brain

Ependymal Cells

Circulate CSF in brain ventricles and spinal column

Satellite Cells

Packing cells between PNS cell bodies

Neuron

A nerve cell that carries electrical signals in the body.

Cell body

Contains nucleus and organelles; processes information.

Dendrites

Receive signals from other neurons

Axon

Transmits signals away from the cell body

Axon terminal

Releases neurotransmitters to communicate with other cells

Myelin sheath

Insulates axon, speeds up signal transmission

Nodes of ranvier

Gaps in myelin that increase signal speed