What Are Neurons?

 

 

Neurons are specialized nerve cells that carry messages throughout the nervous system.

 

They communicate using electrical impulses and chemical signals.

 

There are billions of neurons in the human body, especially in the brain.

 

Parts of a Neuron

 

Every neuron has three main parts.

 

1. Cell Body (Soma)

 

The cell body contains:

 

The nucleus

The cell's DNA

Organelles that keep the neuron alive

 

It is the neuron's control centre.

 

2. Dendrites

 

Dendrites are branch-like extensions that receive messages from other neurons or sensory receptors.

 

Their job is to carry incoming information toward the cell body.

 

Think of dendrites as the neuron's receiving antennas.

 

3. Axon

 

The axon is a long fibre that carries electrical impulses away from the cell body.

 

Many axons are covered by a myelin sheath, which speeds up nerve signal transmission.

 

The axon ends in axon terminals, where chemical messengers called neurotransmitters pass the signal to the next neuron, muscle, or gland.

 

Think of the axon as the neuron's sending cable.

 

Summary Table

Structure Function

Sensory Neurons (Afferent)  Detect stimuli and carry information to the brain and spinal cord.

Interneurons (Relay Neurons) Process information and connect sensory and motor neurons within the central nervous system.

Motor Neurons (Efferent) Carry commands from the brain and spinal cord to muscles and glands.

Reflex Arc   Produces a rapid, automatic response to a stimulus.

The cell body contains the nucleus and keeps the neuron functioning.

Dendrites receive incoming signals from other neurons or receptors.

Axons carry electrical impulses away from the cell body to other cells.

Key Points

Interneurons are found only in the brain and spinal cord and act as the vital link between sensory and motor neurons.

They process information, coordinate movement, support thinking and memory, and help control reflexes.

Reflexes are fast, automatic, and involuntary responses that protect the body and help maintain normal body functions.

A reflex arc allows the spinal cord to produce a rapid response before the brain fully processes the information.

The three main types of neurons are sensory (afferent), interneurons (relay neurons), and motor (efferent) neurons.

Every neuron has three main parts: the cell body, dendrites, and axon, which work together to receive, process, and transmit information throughout the nervous system.