neurons, glial cells and development

What are specialised cells for

To carry electrical signals around the body

Two types of cells and their function

Neurons (nerve cells)- receive, process and transmit information

Neuroglia (glial cells)- supporting cells to protect and maiming neurons allowing them to function properly

What is a dendrite in a neuron

Branched extension that receives information from sensory receptors. Connects to cell body

What is soma

Part of a neurone contains the nucleus

Nucleus

Contains DNA, mitochondria and ribosomes

What is a mitochondria

Generates ATP producing energy

What is a ribosome

In nucleus and synthesises proteins to maintain and repair neurone

What is an axon on a neuron

Longest part of axon responsible for carrying information away from the cell

What is a myelin sheath

Helps signals travel quickly and efficiently along neurone

What is an axon terminal

Junctions that join up with other neurones to pass information from one to the next

Order of how information passes through neurones

1. Dendrites receive signals from another neurone

2. Electrical signals spread towards soma or cell body

3. Neurone combines all the information

4. The combined signals that are sufficient and reach a particular electrical level trigger am action potential

5. Action potential travels along axon towards axon terminals

6. At Axon terminals the neurone passes info to another call

Types of neurones

Sensory neurone

Inner neurone

Motor neurone

What is a sensory neurone

Carry’s information from sensory receptors to CNS

What is a inner neurone

In brain and spinal cord to connect one neurone to another to allow information to be processed and integrated in CNS

What is a motor neurone

To carry information away from CNS to an effector

Main functions of a glial cell

Support neurones to keep them healthy and functioning

Provides structural support by holding neurones in place

Some deliver glucose and oxygen

Four types of glial cells

Adtrocyte

Oligodendrocyte

Swhwann cell

Microglia

What is a astrocyte

Supports neurones by supplying them with glucose to control ions around them

What is an oligodendrocyte

Produces myelin sheath around axon to allow nerve impulses to travel quickly

What is a swhwann cell

Produces myelin sheath on peripheral nerves

what is microglia

immune cells that remove dead cells in nervous system

How does the CNS system develop

Early embryo- the outer layers called ectoderm can develop into the nervous system

Neural plate- the ectoderm thickens to form neural plate

The centre startes to sink and edges fold creating a neural groove

the neural folds move inwards and fuse forming a neural tube

Neural tube develops into a brain and spinal cord

How does the PNS develop

after the neural tube had been developed the cells on the end of the neural tube separate and migrate contributing to PNE