SCIENCE FORM 2CHAPTER 1

THE WORLD THOUGH OUR SENSES

DUNIA MELALUI DERIA KITA

SENSORY ORGANS/ ORGAN-ORGAN DERIA

A stimulus is a change in the enviroment that produces a reaction in living thing/ Ransangan adalah suatu perubahan dalam persekitaran yang menghasilkan gerak balas kepada sesuatu organisma

Sense is the ability of the sensory organ to detect a stimulus/ Deria ialah kebolehan organ deria utk mengesan ransangan(perubahan)

The sensory organ enable a organism to detect changes that occur in enviroment/ Organ deria membolehkan organisma mengesan perubahan yang berlaku di sekelilingnya

All the information from the sensory organ will carry out to the brain to process the information through the nerve system/ Semua maklumat yg dikesan oleh deria akan dibawa ke otak utk diproses melalui sistem saraf

Respons is a reaction produced by stimulus/ Gerak balas ialah tindakan hasil drpd ransangan

Stimulus Sensory organ Nerves Brain Nerves Respons

SENSORY ORGANS/ ORGAN-ORGAN DERIA

SENSORY ORGANS /ORGAN-ORGAN DERIA

Tongue/ Lidah

Skin/ Kulit

Eye/ Mata

Nose/ Hidung

Ear/ Telinga

SENSE OF TOUCH/ DERIA SENTUHAN

Sensory organ response to pain, touch, pressure, heat and cold/ Deria kulit bertindak terhadap kesakitan, sentuhan, tekanan, kepanasan dan kesejukan

Skin also has 5 types of receptorsa) Pain receptor d) Cold receptorb) Touch receptor e) Pressure receptorc) Heat receptor

Sensitivity of skin depends on/ Kepekaan deria sentuhan bergantung kpda) Thickness of skin/ Ketebalan kulitb) Number of sensory nerves/ Jumlah saraf deria

SENSE OF TOUCH/ DERIA SENTUHAN

SENSE OF SMELL/ DERIA BAU

Nose is sensory organ for smell/ HidungOrgan deria bau

Sensory receptor sensitive to chemical in air/ Reseptor deria sensitif kpd bahan kimia dlm udara

The sensory receptor is located at the upper nasal cavity and cover with mucus/ Reseptor deria terletak di rongga atas hidung dan diliputi oleh mukus

When the chemical vapour dissolves, it stimulate and create information to the brain and the brain will identify the smell/ Apabila bahan kimia larut di dalam mukus, ia akan diransang dan menghantar maklumat ke otak dan otak akan menngenalpasti bau tersebut

SENSE OF SMELL/ DERIA BAU

SENSE OF TASTE/ DERIA RASA

Sensory organ for taste is tongue/ Lidah ialah organ deria rasa

Tongue is cover by taste buds which contains many taste receptor/ Lidah diliputi oleh tunas rasa yg mengandungi byk reseptor rasa

TasteTaste

SweetSweet SaltySalty SourSour BitterBitter

BitterBlack coffee

SourLime,

Vinegar

SaltySea water,

salt

SweetHoney, sugar

SENSE OF TASTE/ DERIA RASA

Taste receptor can only detect chemicals in food which dissolved in saliva/ Reseptor rasa boleh mengesan bhn kimia di dlm makanan yg terlarut di dalam air liur

Both of smell and taste are needed to detect flavour of food/ Kedua-dua deria bau dan rasa diperlukan utk mengesan rasa makanan

SENSE OF TASTE/ DERIA RASA

SENSE OF HEARING/ DERIA PENDENGARAN

Ear is sensory organ which detect sound/ Telinga adalah organ yg mengesan bunyi

The eustachian tube and the semicircular canals are NOT involved in the hearing mechanism/ Tiub eustachio dan salur separa bulat TIDAK terlibat dengan bunyi

SOUND PATHWAY/ LALUAN BUNYI

1 2

3

4

56

7

1. Pinna2. Auditory

Canal3.

Eardrum4. Ossicles

5. Oval window

6. Cochlea7. Auditory

nerve8. Brain

THE FUNCTION OF DIFFERENT EAR PARTS/ FUNGSI BAHAGIAN TELINGA

Functions

Pinna - Collect sound waves

- Direct them into auditory canal

Auditory canal - Sends the sound waves to the eardrum

Eardrum - Vibrates the same frequency as the sound

waves

Ossicles - Magnifies the vibration

- Transfer the vibrations from eardrum to oval

window

Cochlea - Detects vibrations

- Converts vibration to nerve impulses

SENSE OF SIGHT/ RANGSANGAN PENGLIHATAN

SENSE OF SIGHT/ DERIA PENGLIHATAN

Eye is a sense organ that detect light/ Mata ialah organ yang mengesan cahaya

Made up of three layers/ Terdiri daripada 3 lapisan

a) Sclera – outher layer/ sklera – lapisan luar

b) Choroid – middle layer/ koroid – lapisan tengah

c) retina – innermost layer/ retina – lapisan paling dalam

Parts of eyes that help focus the light onto retina/ Bahagian mata yang menolong memfokuskan cahaya ke dalam retina ialah a) Cornea/ Kornea b) aqueous humour/ gelemairc) lens/ kanta d) vitreous humour/ gelemaca

Eye able to focus light by changing the thickness of the lens/ Mata boleh memfokus cahaya dgn menukar ketebalan kanta

SENSE OF SIGHT/ DERIA PENGLIHATAN

The light path in the human eye is shown below

CorneaCornea Aqueous humourAqueous humour PupilPupil

LensLensVitreous humourVitreous humourRetinaRetina

Optic Optic nervenerve

FUNCTION OF THE DIFFERENT PART OF EYES/ FUNGSI BAHAGIAN MATA

Structure/ Struktur

Functions/ Fungsi

Sclera - Protect the eyes

Choroid - Support food and oxygen to the eyes- Absorb light and prevent reflection of light

Retina - Detect light- Produces nerves impuls

Yellow spot - Detect images of formed on it

Cornea - Helps to focus light on retina

Iris -Controls the size of the pupil-Controls the amount of light entering the eye

Pupil -Allow light to enter the eye

Structure/ Struktur Functions/ Fungsi

Lens - Focuses light on the retina

Suspensory ligaments - Holds the lens in place

Ciliary body - Changes the thickness of the lens

Aqueous humour - Helps to focus light on retina

Vitreous humour - Helps to keep the eye ball firm

Optic nerve - Sends nerve impuls from the retina to the brain

FUNCTION OF THE DIFFERENT PART OF EYES/ FUNGSI BAHAGIAN MATA

LIGHT AND SIGHT/ CAHAYA DAN PENGLIHATAN

1. Reflection and Refraction/ Pantulan &

Pembiasan

- Light can be reflected and refracted

- Reflection is bouncing of light off an object or surface/ Pantulan ialah pembalikan cahaya daripada objek atau permukaan

- We can see because the object reflects light into our eyes/ Kita boleh melihat sesuatu objek krn cahaya telah dipantulkan ke dalam mata kita

- - For examples,a) Dentist use the mirror to see the teethb) Contexs mirror at the bend road for safetyc) Vehicle rear-view

- Refraction is the bending of light as it passes from one transparent medium to another/ Pembiasan ialah pembengkokan cahaya apabila ianya melalui bahan lutsinar yang berbeza ketumpatan

As example, Pencil in this picture looks like bending in water. It’s actually not bending, but the light will reflection as it pass though the water which has different density.

It is bending or not?

Actually fish located

Fish located in our eyes

Defects of vision and ways to correct them/Kecacatan pada penglihatan dan caraMembetulkannya

The common defects of vision is/Kecacatan mata yang biasa ditemui ialaha) Long sightedness/ Rabun jauhb) Short sightedness/ Rabun dekatc) Astigmatism/ Astigmatisme

SHORT SIGHTEDNESS/ RABUN DEKAT Can see NEAR objects/

Boleh melihat objek dekat

FAR object appear blurredObjek yg jauh kabur

Image formed in FRONT of the retinaImej terbentuk di hadapan retina

IMEJ DI HADAPAN RETINA

Cause:-Eye ball is too big/long

Bebola mata terlalu besar/ panjang

Lens is too thickKanta mata yg TEBAL

Correction:- Use suitable concave lens

Gunakan kanta cekung

LONG SIGHTEDNESS/ RABUN JAUH

Can see FAR objects/Boleh melihat objek JAUH

NEAR object appear blurredObjek yg DEKAT kabur

Image formed in BEHINDof the retinaImej terbentuk di BELAKANG retina

IMEJ DI BELAKANG RETINA

Cause:- Eye ball is too SMALL/SHORT

Bebola mata terlalu KECIL/ PENDEK Lens is too THIN

Kanta mata yg nipis

Correction:- Use suitable CONVEX lens

Gunakan kanta CEMBUNG

LIMITATION OF SIGHT

Some common examples of the limitation of sight are

a) Blind spot b) Optical illusion c) Monocular and stereoscopic visions

DEVICES TO OVERCOME THE LIMITATION OF SIGHT

DEVICES TO OVERCOME THE LIMITATION OF SIGHT/ Alat untuk mengatasi had penglihatan

Device Function

Microscope To examine a very tiny organisms/ utk memeriksa organisma yg terlalu kecil

Magnifying glass

To magnify the image of small object/ utk membesarkan objek yg kecil

Telescope Enables us to see a far object/ membolehkan kita melihat objek yg jauh

Binoculars Enables to see far away object/ membolehkan melihat objek yg jauh

Ultrasound scanning

Enables to see the fetus of pregnant mother/ melihat janin pd ibu mengandung