NERVOUS SYSTEM Human physiology. THE BODY’S CONTROL CENTER The brain is the control center of the human body. It is made up of billions of nerve cells,

NERVOUS SYSTEM

Human physiology

THE BODY’S CONTROL CENTER

The brain is the control center of the human body.

It is made up of billions of nerve cells, or neurons.• Sends messages around the body• Receives messages from the body• Stores information

THE BODY’S CONTROL CENTER

Message go from your brain down to your spinal

cord.• Big rope of nerve cells• Runs along the inside of your back bone• Connects to neurons all over your body

THE BODY’S CONTROL CENTER

Hormones are substances made by organs called

glands• Hormones control body functions• Some circulate in the blood and cause changes• Estrogen and testosterone are examples of

hormomes

THE NERVOUS SYSTEM

Body parts: brain, spinal cord, sense organs and

neurons are all parts of the nervous system

Function of the nervous system: Main

controlling and communicating system of body

THE FIVE SENSES

All part of the nervous system

Sight – eyes are organs of sight

Hearing – ears are organs of hearing

Taste – tongue is the organ of taste

Smell – nose is the organ of smell

Touch – skin is the organ of touch

SIGHT

Sight – eyes are organs of sight• Light bounces off objects and enter your eye• Nerves in back of eye sends messages to brain

HEARING

Hearing – ears are organs of hearing• Sounds are made by vibrations• Tiny bones in your ears pick up vibrations• Nerves pick up movement and send message to

brain

TASTE

Taste – tongue is the organ of taste• Four types of flavors: sour, sweet, salty and bitter• Different areas of tongues taste different flavors• Taste buds pick up tastes and send them to brain

SMELL

Smell – nose is the organ of smell• Molecules leave object and trigger nerve cells in

nose• Sends messages to brain

TOUCH

Touch – skin is the organ of touch• Some areas are more sensitive to touch than others• Fingertips very sensitive to heat, cold, touch and

pain• Skin is the largest organ of body• Also part of immune system – keeps germs out of

body

EXIT SLIP

1. List the five senses and the organs that go with

that sense

2. What are the parts of the nervous system?

3. What does the nervous system do (function)?