Unit 4

The Nervous System

• It carries out the function of sensitivity�
• it is in charge of THREE important tasks:�- it receives and interprets information from external and internal environments�- it gives orders for our body to respond�- it controls and coordinates all organs and systems in our body

THE NERVOUS SYSTEM

The nervous system

Can you fill in the blanks?

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The nervous system is made up of _____ parts. The ________ ________ ________ and the ___________ ________ ________. It is formed by one type of tissue, ________ ________.

TWO

CENTRAL

NERVOUS

SYSTEM

PERIPHERAL

NERVOUS

SYSTEM

NERVOUS

TISSUE

neurons

Nervous tissue consists of nerve (elscl) _____ or neurons

Neurons group together to form nerves.

Neurons have three parts:

• the (oybd) ____, which is the widest part.
• (nediersdt)_________ which receive messages from the (nsese)_____ organs or other neurons.
• The (onxa)____, which transmits messages to other neurons

cells

body

dendrites

sense

axon

the central nervous system

The central nervous system has TWO parts:

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-

The _____ is protected by the _______ and has THREE parts

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THE BRAIN

THE SPINAL CORD

BRAIN

CRANIUM

CEREBRUM

CEREBELLUM

BRAINSTEM

the CEREBRUM, the CEREBELLUM and the BRAINSTEM

THE CEREBRUM

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THE CEREBELLUM

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THE BRAINSTEM

controls movement, coordination and balance

controls internal organ activities that we do not need to think about

controls voluntary actions, like running and talking

the spinal cord

The spinal cord is a long, thin bundle of . It

extends from the base of the to the bottom of the �� and connects the brain and the ���The spinal cord produces responses, for ��example, when we move our hands away from very hot objects.

NERVOUS TISSUE

BRAIN

SPINE

INVOLUNTARY

peripheral nervous system

the peripheral nervous system

The peripheral nervous system consists of (dendrites/nerves) that extend throughout the body.

There are two types of nerves:

_______ nerves. These (receive/send) messages from receptors in the sense organs and (receive/send) these messages to the central nervous system.

_____ nerves. These (receive/send) orders from the central nervous system to the other organs.

SENSORY

MOTOR

voluntary movements

These are actions that we perform consciously. We are aware of them and can start and stop them as we wish.

reflex movements

These are automatic movements that we make without thinking about them. In many cases, they are movements to protect us from being hurt in dangerous situations.

which of these are voluntary movements and which are reflex movements?

voluntary

reflex

playing football

driving a car

yawning

singing

moving your hand away from something hot

jumping at a loud noise

health risks

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what can damage our nervous system?

sports accidents

reading a book

Diseases like Parkinson’s or Alzheimer’s disease

alcoholism

sleeping 8 hours a night

traffic accidents

diseases

Alzheimer’s disease involves:

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Parkinson’s disease involves:

a loss of memory

involuntary tremors

now let’s play a game!