Nervous tissue

Central nervous system location

Brain, spinal cord

Cells of nervous tissue

Neurons, neuroglial

Functions of the nervous system

Sensory input, integration, motor output

Sensory input

Sensory receptors (ex. eyes, ears) gather information from the outside world and send it to the brain

Integration

The brain processes and understands the input and decides what to do in response

Motor Output

The brain sends a message to the muscles or glands to cause a response

Neurons

Send impulses (messages) from one part of the body to another; have a long lifespan; amitotic: don’t divide; require constant oxygen and die quickly without it

Neurglial

Fill spaces between neurons and support them; smaller than neurons

Neuroglial Cells of the central nervous system

Astrocytes, microglial, ependymal, oligodendrocytes

Astrocytes

Largest and most numerous; anchor neurons or blood capillaries

Microglial

Sense and approach injured neurons; phagocytose bacteria and debris

Ependymal

Use cilia to circulate cerebrospinal fluid around the brain & spinal cord

Oligodendrocytes

Form myelin sheath in the CNS (an insulating covering)

Neuroglial Cells of the peripheral nervous system

Satellite, Schwann

Satellite

Surround the cell body of a neuron; regulate levels of oxygen, CO2, and nutrients

Schwann

Form myelin sheath in the PNS