The eye

The eye Revision Lesson


Parts of the eye

Can you name the parts?

Use the blank diagram above to describe what happens from light enters the eye .

Now watch this video clip to see how right you were.

How the eye works or do you prefer this one?

How about this short quiz.

1. Into how many sections is the eye divided in?

2. What is the innermost layer called?

THE EYE

The Eye

The eyes are the organs of sight. They are two in number. Each eye is shaped like a ping pong ball. The eye consists of three layers. The innermost layer is called the retina. The diagram below shows the different parts of the eye.

Read more more information about the eye.

The parts of the eye.

Every part of the eye has a function. Each part works together to enable sight.

HOW THE EYE WORKS

Assessment

(A) Complete this short quiz.
.
(B) Use the words from the word bank to correctly label the eye.

(C) Try this experiment. What did you find out? What conclusion can you draw?

JOINTS

Joints are the points at which bones meet.


Examples of joints

hinge, pivot, gliding, ball and socket

Importance of joints in movement

THE SKELETON

THE SKELETON

The skeleton is the bony framework of the body. It consists of approximately 206 bones.

Diagram of the skeleton

The skeleton has a number of functions.

1. It enables movement or locomotion.
2. It provides support for the body
3. It protects vital organs of the body. For example, the ribcage protects the heart, etc.

Watch the video clip for more information on the skeleton.

Assessment

(A) Read this information and make your notes.

(B) Complete this quiz.

(C) Label the skeleton correctly.

Have fun looking !!!!

The Reproductive System

Reproduction is the ability to reproduce.

Male Reproductive Organ

a sperm

Female Reproductive Organ

ovary

Assessment 1
1. Use mouse to label the parts of the reproductive system in humans

Landforms and Water Bodies

The part of the earth which we know a lot about is called the crust.
The earth is made up of about 71% water and 29% land. The percentage water include oceans (which are the largest sheets of water, and surround the continents), seas, rivers, lakes and ponds. The 29% land include continents and landforms.

The Continents

These are seven in number, namely:

Asia
Europe
Antarctica
Australia
Africa
North America
South America

Assessment 1

1. Follow the given direction and correctly name the continents.

Landforms

Landforms include mountains, hills, valleys, plains and plateaus


WATER BODIES

The Oceans

The part of the earth that is not land is water. Water bodies include, the five oceans, namely:

Indian Ocean,
Pacific Ocean
Atlantic Ocean
Southern Ocean
Arctic Ocean

Other water bodies include, sea, rivers, lakes, ponds.

ANGLES

ANGLES

An angle is the space formed between two lines that meet.
There are different types of angles. Some of these include, acute angle, right angle, obtuse angle, straight angle and reflex angle. Angles are named based on their sizes. We use an instrument called a protractor to measure the size of an angle.

ACUTE ANGLE

An angle which measures less than 90 degrees is called an acute angle.

RIGHT ANGLE

Angles which measure 90 degrees are referred to as right angles.

OBTUSE ANGLE

Any angle which measures more than 90 degrees but less than 180 degrees is called an obtuse angle.

STRAIGHT ANGLE

An angle that measure 180 degrees is called a straight angle.

REFLEX ANGLE

If an angle measures more than 180 degrees but less than 360 degrees, it is called a reflex angle.



CULMINATING ACTIVITY (Assessment 1)

(a) Identify the angles depicted by teacher/student

(b) Use the mouse to illustrate the angle suggested by the teacher

(c) Complete the short quiz. (Good Luck!)

THE EAR

THE EAR
The ears are the organs of hearing. They are two in number. They are incharge of collecting sounds, processing them, and sending sound signals to the brain. Not only that, but the ears also help us to keep our balance.

The ear is made up of three different sections: the outer ear, middle ear and inner ear. These parts all work together so that we can hear and process sounds.

THE OUTER EAR
The pinna or earlobe (auricle) is the outer part of the ear. It is the part that we can see. The main job of the pinna is to collect sounds. The outer ear also includes the ear canal, where wax is produced. The ear wax protects the canal by fighting infections if they enter the ear canal. Sounds from the pinna are conveyed to the ear canal or hearing canal, which is later sent to the final part of the outer ear-the eardrum.

THE MIDDLE EAR

This part of the ear consists of the three little bones: the hammer, anvil and stirrup. They are the tiniest and most delicate bones in the entire body. They are referred to as ossicles.

After sound waves leave the outer ear, they make their way to the middle ear. The job of the three bones is to amplify or speed up the vibrations, and deliver them to the inner ear.

THE INNER EAR
This section of the ear consists of a coiled tube called the cochlea, which is filled with liquid. It also contains tiny cells covered in tiny hairs. The cochlea is set in motion (like a wave) when the three bones pass on the vibration to it. The last little bone in the middle ear (stirrup) rests on the cochlea. When sound reaches the cochlea, the vibrations (sound) cause the hairs on the cells to move, creating nerve signals. The signals are sent to the auditory nerve, (which forms part of the inner ear). This nerve takes sound signals to the brain, where the signals are decoded or interpreted as sounds.

The semicicular canals which are also found in the inner ear, are three small loops above the cochlea. These help us to keep our balance.

HOW WE HEAR SOUNDS (in brief) (1) How we hear (Part 2)

When objects in the environment vibrate, they produce sounds. These sounds are picked up by the pinna. The pinna passes sound signals along the hearing canal. At the end of the canal is the eardrum. When sound hit the eardrum, it causes it to vibrate. Because the first bone (hammer) rests on the eardrum, the vibration is passed on to the bones and conveyed to the other two. These bones amplify or speed up the vibrations.

The last bone (stirrup) which fits into a window in the cochlea, allows the vibrations to be passed on to the cochlea. The vibration of the cochlea changes the sounds into nerve signals, which are later carried to the brain by the auditory nerve. In the brain, it is decoded or interpreted.

Culminating activity

1. A little activity for you.

2. Complete this quiz correctly.
3. Name the numbered parts of the ear.
4.Use the mouse to label the ear correctly.

EAR LOSS

The inability to hear sounds is called deafness.

There are a number of factors that can cause loss of hearing. Some of these include:

(a) too much continuous noise (noise pollution)

(b) damaged ear parts

(c) infection of ear

To prevent ear loss, we need to :

a. do not swim in dirty water

b. do not allow people to shout in your ears

c. avoid listening to loud music

d. use ear muffs if you work in noisy areas

Hearing aids can be used to help partially deaf persons.

The Solar System 1

WHAT IS THE SOLAR SYSTEM?

The Solar System is made up of the sun (a star), the planets, and their moons (over 162). There are also other bodies like dwarf planets, comets, asteroids and other space rocks, which make up the Solar System. It is believed that the Solar System has over one hundred (100) worlds. The word solar refers to the sun.

Our Solar System is part of a galaxy known as the Milky Way, and the sun is the centre of the Solar System. The Sun contains about 98% of all the materials in the Solar System. The larger an object is, the more gravity it has. Because the sun is so large, its powerful gravity attracts all the other objects in the Solar System towards it.

Everything in the Solar System orbits or revolves around the sun. This is done in an orderly way. Each planet revolves around the sun on its own path called the orbit. Each planet's orbit is elliptical in shape. There are eight planets in the Solar System. These are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

The planets in the solar system are categorized as inner planets and outer planets. The inner planets are Mercury, Venus, Earth and Mars. The outer planets are Jupiter, Saturn, Uranus and Neptune. The asteroid belt separates the inner planets from the outer planets.

Get more information on the planets. Take a look at earth as it orbits the sun.

Other bodies in the Solar System

Apart from the planets and their moons, there are other bodies which revolve around the sun. Some of these are listed below.

(A) Asteroids

Asteroids are a class of small solar bodies which orbit the sun, They have been referred to at times as planetoids, especially the larger ones. They are made of rocks. Asteroids Belt separate the inner planets (terrestrial bodies) from the outer planets.

(B) Comets

A comet is an object of frozen gases, dust and rocks, which travel around the sun in a huge elliptical orbit. Comets are named after the people who discovered them. Example Halley Comet, which appeared in 1986. Comets are distinguished from asteroids by the presence of a tail.

(C) A meteor

A meteor is commonly referred to as a 'Shooting Star' or a falling star.

(D) Meteoroids

A meteoroid can be defined as a solid object moving in space. It is said to be much smaller than an asteroid.

A little test for you

1. What is the centre of the solar system?

2. List the planets in order.

3. How many planets are further from the sun than earth?

4. Why do you think the planets do not fall out of their orbits?

5. Which planet is called the giant planet?

6. What separates the inner planets from the outer planets

7. Which of the bodies in the solar system has the greatest

mass?

8 Which is the coldest planet and why?

9. Why is Earth considered special and unique?

10. What is the shape of each orbit?

11. Which of the planet is spherical in shape, has only one moon

and is a terrestrial body?

Try this game

Earth's movement

While earth is revolving around the sun it is also rotating on its axis.

The rotation of the earth causes day and night.

The revolution of the earth brings about seasonal changes.

Earth quakes and volcanoes also come about because of earth's movement.

This clip shows how an earthquake happens.

Earthquake regions