The New Childrens Encyclopedia

THINK! ACT!

281

Dendrites pick

up nerve signals.

BRAIN CELL

OR NEURON

The nervous system is made up of

the CNS and the peripheral nervous

system, which consists of nerves that

branch to the rest of your body. It’s

hardworking and fast; a nerve impulse

travels from the big toe to the spinal

cord in one-hundredth of a second.

The nucleus of the

cell controls the

cell’s activity.

The axon, a nerve fiber,
takes electrical impulses
away from the cell body to
other neurons.

HARD HAT
The human brain is
soft and squishy so it
is protected in a bony
case called the skull.

The heavily folded

cerebrum is the

largest part of your

brain.

The brain stem works

at the same level when

you’re asleep and awake.

The hypothalamus

plays a part in thirst,

hunger, and temperature

control.

The thalamus

passes messages

between the brain

and spinal cord.

The cerebellum

deals with

movement.

The cerebral cortex

is the surface of the

cerebrum.

Cell body

YOUR BRAIN

Sight, hearing, speaking, and thinking

are controlled in different areas of the

cerebrum. Hearing uses an area linked to

the ears’ nerves. Sight involves a small

area linked to the eyes’ nerves. Thinking

and speaking use large areas of the brain.

Heat scans show the different areas.

SIGHT

SPEAKING

HEARING

THINKING

THE HUMAN BODY

Parts of the brain

The main regions of the

brain are the cerebellum,

the brain stem, and the

cerebrum. The cerebrum

is responsible for many

complex everyday activities,

from eating to speaking.

Neurons are thin cells that

carry electrical signals called

nerve impulses. A neuron

has a cell body, with short,

spreading projections

called dendrites. An

axon connects to

other neurons.