Anatomy Lecture 10 (Nervous System) SG

The nervous system is composed of

CNS and PNS

Glial cells

Cell that provides physical and chemical support to neurons and maintain their environment. In CNS and PNS.

CNS glial cells

oligodendrocytes
astrocytes
ependymal cells
microglial cells

PNS glial cells

Schwann cells
Satellite cells

Neurons

Information messengers
Use electrical impulses and chemical signals

PNS

contains all nerves that lie outside of CNS

What is the role of the PNS?

to connect the CNS to organs, limbs, skin

Nervous tissue develops from

ectoderm

CNS is made of

the brain and spinal cord

Neurons can communicate with

glands, neurons, and muscles

Action potential

electrical signals

Neurotransmitters

chemical signals

Glial cells are

nonexcitable, meaning they do not receive signals

Injured nerves in the CNS are

not regenerative

Somatic nervous system

controls muscle movement and relays signals to eyes, ears, mouth

Peripheral nerves are

regenerative

Soma/ cell body

where all the genetic information is stored.
organizes and keeps the cell functional

Function of an axon

where electrical impulses from the neuron travel away to be received by other neurons. transfers signals to other cells and organs.

Axon hillock

site of transmission between cell body and axon.
generates impulse in the neuron

Where do you find the myelin sheath?

wrapped around each nerve cell

Myelin sheath is made of

fat and protein

Dendrites are

relatively short structures

Schwann cells

myelinating cells in PNS

Astrocytes

large star shaped glial cells in CNS that help hold nerve cells in place, help them develop and work the way they should

Microglial cells

small phagocytic glial cells in CNS.
play a role in injury repair.
protect CNS from microorganisms

Ependymal cells

glial cells in CNS that produce cerebrospinal fluid (CSF)

Cerebrospinal fluid (CSF)

eliminates waste in brain and spinal cord