Today

we will talk about an organ

that rules all of our body

and that is our brain.

As it is the most sensitive organ,

our brain is kept inside the bony covering called skull.

From doing physical activity

to solving logical problems,

from dealing with emotions and feelings

to creativity,

brain is responsible for all.

Therefore,

it never sleeps.

Our brain can be divided

into three main parts;

the cerebrum,

the cerebellum

and brain stem.

Cerebrum is the largest part of brain,

which can be further divided

into right and left halves

called hemisphere.

Each cerebral hemisphere has four lobes

namely frontal lobe,

parietal lobe,

occipital lobe

and temporal lobe.

Each lobe performs different functions.

Cerebellum is responsible

for movement and coordination.

It gives you sense of balance

and thus prevents you from falling down.

Brain stem includes mid brain,

pons and medulla oblongata.

It controls your body's involuntary actions

like breathing,

heart rate and blood pressure.

Brain comes under a system

called nervous system.

Structurally,

nervous system is classified into two types:

Central Nervous System (CNS)

and Peripheral Nervous System (PNS).

The Central Nervous System

comprises of the brain and spinal cord.

The spinal cord is the bridge

that connects the brain

to peripheral nervous system.

It starts from medulla oblongata

and stretches to lumbar region of the spine

or vertebral column.

The Peripheral Nervous System is a network of nerves

spread across our body.

Think of Peripheral Nervous System

as a network of highway

that connects the body

with Central Nervous System.

This highway has two way traffic.

Let's see how.

When you hold a hot cup of coffee,

sensory neurons in your hand

transmit signal to brain

through sensory neurons,

also called afferent neurons,

that the cup is hot.

Your brain process that information

and send response through motor neurons,

known as efferent neurons,

that you must put that cup back.

PNS consists of total 43 pairs of nerve,

among which

12 originate in brain,

named as cranial nerves

and 31 originate from spinal cord,

hence called as spinal nerves.

Here you hear the word “neuron”.

Neuron is the basic unit of nervous system.

It is the nerve cell

which transmit electrical signals to brain.

A neuron has three parts:

Dendrites,

soma or cell body,

and axon.

Dendrites serve as input device for neuron

because it receives input

from other nerve cells.

Soma or cell body of neuron contains nucleus.

Axon serve as output device

from where it transmit electrical response

to other neurons.

I hope this helps you

in understanding nervous system.