A system that controls all the activities of the body.

The nervous system is made of:

The brain The spinal cord

The nerves

The nervous system also allows you to react to a stimulus.

A stimulus is a change in the environment

that causes reactions.Example: A hot stove

Or… tripping over a rock

Messages carried throughout the body by nerves.

Your reactions are automatic.

Automatic means that you do not have to think about your

reactions.Example: If a bug flies by your eye,

you will blink.

You have a nerve along your whole arm.

The “funny bone” is the only place on the arm where the nerve is not

protected.

The “funny bone” is on the elbow.

The Central Nervous System is made of the brain and the spinal

cord.

The Central Nervous System controls everything in the body.

The Peripheral Nervous System is made of the nerves and the sense

organs.

Nerves Sense organs

* The Central Nervous System controls all the body’s activities.

* The Central Nervous System is made of two main organs.

1. The brain

2. The spinal cord

• It is a cylinder of nerve tissues (a finger thick & 45 cm long).

•It connects the brain to the sense organs and the different parts of the body.

•The spinal cord relays messages to and from the brain.

• It controls some important body actions that don’t involve the brain (reflexes).

* The vertebrae are the many bone The vertebrae are the many bones that protect the nerves in the spinal cord. The vertebrae are the many bones that protect the nerves in the spinal cord. s that protect the

nerves in the spinal

(SPINAL COLUMN)

The vertebrae are the many bones that protect the nerves in the spinal cord.

•An automatic reaction that happens without thinking about it.

•A body action that doesn’t involve the brain because it is controlled by the spinal cord.•A reflex is a protective action.

•It happens quickly in less than a second.

* The brain controls everything in the body.

* The brain is made of more than 10 billion nerves!

* The brain is divided into three parts and is protected by the skull.

An organ that controls your emotions, your thoughts, and every movement you make.

* The Brain has three main parts…

1. The Cerebrum

2. The Cerebellum3. Medulla Oblongata ( part of the The Brain Stem)

* The Cerebrum is the largest part of the brain.1. The cerebrum controls

your thinking and reasoning.2. The cerebrum controls your memory.

3. The cerebrum controls your speaking.

4. The cerebrum controls your movement and identifies the information gathered by your sense organs.

* The cerebellum is below and to the back of the cerebrum.1. The cerebellum controls your balance.2. The cerebellum controls your

posture.

3. The cerebellum controls the voluntary muscles (voluntary actions).

•The part of the Brain Stem that connects the brain to the spinal cord.

• The nerves in the brain stem control your involuntary actions---heartbeat, breathing, and blood pressure.

•The PNS’ job is to connect the Central Nervous System to the rest of the body.

•Nerves outside the CNS– 12 pairs of cranial nerves and 31 pairs of spinal nerves

* The PNS carries messages between the central nervous system

and the rest of the body.

•Divisions:

1.Somatic Nervous System- controls the actions of voluntary muscles like the muscles of the arms, legs, & face.

2.Autonomic Nervous System- is responsible for the functions of the heart, lungs, glands, blood vessels, and smooth muscles of the digestive system.

* The outer nervous system controls the body’s activities that you don’t think about.

* The outer nervous system controls activities in your small

intestine, your breathing, and your heartbeat.

controls

* The PNS is made of the nerves and the sense organs.

EarEye

Skin Nerves

Tongue

Nose

Parts of the Nerve Cells/ Neurons

• Cell Body - center of the neuron which contains the nucleus. It controls the nerve cells.

• Dendrites – pick up impulses and carry these to the cell body.

• Axon – carries impulses away from the cell body to other neurons, to the muscles or glands.

Parts of the Nerve Cells/ Neurons

How An Impulse Is Transmitted From One Neuron To Another Neuron

Kinds of Neurons

• Sensory Neurons- carry impulses from the sensory receptors to the CNS.

• Motor Neurons – carry impulses from the CNS to the muscles and glands.

• Association/Interneuron Neurons – relay impulses between sensory and motor neurons.

- found in the CNS (brain and spinal cord)

How messages travel through the body?

• Stimulus received by the receptor cells converted to impulse travels through sensory and association neurons relay the message to brain or spinal cord processes information and sends signals to motor neurons carry message to muscle/body part carries out response or reaction

How messages travel through the body?

Sense organs carry

messages about the

environment to the central

nervous system.

The eyes, ears, nose, tongue, and skin are examples of sense

organs.The sense organs gather

information (light, sound, heat, and pressure) from the

environment.

The environment is everything outside the body.

The sense organs gather information from outside the

body, then send the messages to the brain.

Vision is your ability to see.

Vision involves the eye and the brain.

The eye is one of your sense organs.

The eye is made of the iris and the pupil.

The eye gathers pictures and sends them to the brain.

The colored part of the eye is

the iris. The black part of the eye is the pupil.

The pupil becomes larger and smaller as it controls the

light coming into the eye.

IrisPupil

When a sound is made, the air around the sound vibrates.

Hearing starts when some of the sound waves go into the

ear.

There are nine main parts of the ear.1. Pinna

2. Ear canal3. Ear drum

5. Anvil

6. Stirrup

7. Cochlea

4. Hammer 8. Eustachian tube9. Auditory nerve

The ear canal is the tube between the outside of the ear and the ear drum.

The ear drum is in the middle ear. It vibrates when sound waves hit it.

The pinna is the part of the ear that you can see.

The three smallest bones in the body, the hammer, the anvil, and the stirrup,

are in the middle ear.

The hammer gets the vibrations from the eardrum, then sends them to the

anvil.The anvil passes the vibrations to the stirrup.

The stirrup passes the vibrations to the inner ear.

The inner ear is made of the cochlea and liquid.

The cochlea is in the inner ear. The cochlea looks like a shell.

The Eustachian tube controls the amount of pressure in the ear.

The auditory nerve carries the hearing information to the brain and

the brain tells us what we heard.

The ear works with the brain to control your balance.

All of your movements are controlled by balance and muscles.

The liquid in your inner ear is responsible for your balance.

The liquid in your ear moves when we move. The liquid movement sends

information to the brain to tell it how we are moving.

The sense of touch is located in the skin.

The nerves in the skin allow us to feel texture, pressure,

heat, cold, and pain.

Texture is how something feels.

The nose controls your sense of smell.

The nose is able to smell 80 different kinds of smells.

Your sense of taste comes from the taste buds in the tongue.

Taste buds are the parts on the tongue that allow us to taste.

The four kinds of taste buds are sweet, sour, bitter, and salty.

Tastes and smells work together to make flavors.

Flavors are the tastes of food and drinks.

DISEASES OF THE NERVOUS SYSTEM

• Cerebral Palsy – it is caused by a damage to the brain of a newborn baby during birth. Lack of oxygen or injury usually causes the brain damage. The victims may have trouble walking, speaking and using his/her hands.

• Infantile Paralysis – also known as poliomyelitis (polio) – a disease affecting the gray matter of the spinal cord. It starts with fever, headache, sore throat and stomach upset. This may result in paralysis, which is most common in lower limbs.

• Meningitis – infection caused by germs. Certain germs may outsmart our body defenses and spread inside our body. Some of these germs infect the central nervous system harming the meninges and causing meningitis.

• Parkinson’s disease – this is a progressive disease of the nervous system. This disease affects adults and is characterized by uncontrollable shaking of the limbs.

• Hydrocephalus – is congenital or present at birth. It is characterized by an accumulation of fluid inside the skull.

•Amnesia Amnesia is the complete

or partial loss of memory

due to brain damages/injuries.

a. Organic amnesia-is caused by head injuries, severe illness, old age, alcoholism , stroke.

b. Functional amnesia- caused by trauma or stress

•Alzheimer's Disease It is described as mild

memory lapses that lead to permanent memory loss.

•Stroke A stroke is a condition where

a blood clot or ruptured artery or blood vessel interrupts blood flow to an area of the brain. A lack of oxygen and glucose (sugar) flowing to the brain leads to the death of brain cells and brain damage, often resulting in an impairment in speech, movement, and memory.

•Brain Tumor Brain tumor is an abnormal

cell division in or on the brain. It may arise from tissues within the skull or spread through the bloodstream from tumors in some parts of the body.

Proper Care Of The Nervous System

• Proper Nutrition- balanced diet for right nutrients to think quicker, have a better memory, and improved concentration;

vitamins B1-thiamin & B12 for proper functioning;

minerals (Ca, K, Na --for transmission of nerve messages & Fe for Oxygen supply)

• Have sufficient sleep, rest, and recreation.

• No to alcohol, drug abuse, and smoking.

• Avoid falls and injuries that can cause injuries to your brain and spinal cord.

• Learn to cope with stress.