Nerves

Different Types of Cells

There are three main types of nerve cells that are in our body. They include:

• Sensory nerves
• Relay nerves
• Motor nerves

While there may be more, they fall under the same category as these.

Here is a YouTube video from FuseSchools on nerves:

Types of Nerves

Sensory nerves: they allow us to sense things around us. Like, when we place our hand above a candle, we will feel our hand getting hotter from underneath. They also allow us to react to it (called a reflex action).

Relay nerves: These are between the motor nerve, and the sensory nerves. They are located in the brain and spinal cord, and allow the other nerves to communicate between each other.

Motor nerves: these allow us to move our body. Impulses come from the brain to tell us to move a part of our body - like while I'm typing this, my brain is telling my fingers to touch type the letters on to the document I'm typing it on.

Interesting fact: despite the rest of our body having the capability of being able to regenerate itself to some degree, our nerves/neurons do not have this function, which is often why nerve damage is permanent.

Parts of a Nerve

There are several parts of a nerve, including:

• Axon
• Myelin sheath
• Dendrites
• Pre-synaptic terminal
• Cell body
• Receptor Cell

Axon

The Axon is a strand of the nerve cell that carries information from one end of the nerve cell to the other end of the nerve cell. They are very thin fibres that connect to other neurons (nerves), and also muscle or gland cells.

Myelin Sheath

The myelin sheath is a kind of jacket for the axons in the cell. This keeps it all intact and protects it from any form of intrusion. It's made from fats known as lipids and protein that coat each part of the cell called the axon.

Dendrites

At the end of the cell body are little protrusions, which attach to the other nerve cells or muscles in order to transmit chemical reactions to the next nerve.

Pre-synaptic Terminal

Literally just before the information is sent between each nerve cell, it has to travel through the pre-synaptic terminal. These have tiny little gaps that are called synaptic clefts. They allow for transmission of data and information between them to create the chemical reaciton needed.

Cell Body

Usually situated within the middle of the cell, the cell body houses the nucleus of the nerve cell. It works in a similar fashion to a regular cell, like a tissue cell or a muscle cell, and houses other organelles.

Receptor Cell

A receptor cell is similar to the dendrites in the fact that they connect to other neurons, however, these are closed in, and not free. Being encapsulated means that they allow for more protection.