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Presentation on theme: "THE WORLD THROUGH OUR SENSES"— Presentation transcript:


2 Receptor
Our body have different types of receptors. These are: pain receptor touch receptor heat receptor cold receptor pressure receptor


4 Human skin

5 Try to answer A B C D 5 1 6 2 7 3 8 4

6 The degree of sensitivity of the skin depends on the:
1.Thickness of the epidermis The thinner the epidermis, the more sensitive the skin is to the stimulus 2. Number of receptors present PMR 05 The more receptors found on the skin the more sensitive is that part of the skin.

7 Other functions of the human skin.
Water proof prevent water loss from skin. Prevents entry of microorganisms that cause illnesses. Remove waste products excess water, urea and mineral salts. Produces Vitamin D in the presence of the sunlight. Stabilise body temperature

8 Fill in the blank with the suitable terms given in the box.
Receptors thickness thinner sense of touch touch more number  The skin is an organ of __________________ There are five types of __ ___ in the skin sensitive to various stimuli. The sensitivity of the skin depends on the ___________ of the epidermis and the ____________ receptors on the skin. The ____________ the epidermis, the more sensitive it is to stimulus. The ________ receptors there are on the skin, the more sensitive it is to stimulus. Blind people use their ____ to help them read Braille

9 Human Tongue

10 Try these 6 1 3 4 2 5

11 PMR 2012

12 Human nose

13 Try to answer …. G A B H C I D J E K L F

14 Sense of smell When we have a cold or flu, a lot of mucus is produce. The smell receptors are surrounded by this thick layer of mucus and vary little of chemical vapor gets to the smell receptors. Therefore, the smell receptors do not get stimulated enough to effectively function as a sensory organ of smell.

15 The sensitivity of the nose towards stimuli is influenced by the following factors: PMR 05
The strength of the smell. A stronger smell will be detected by the nose easily compared with a weaker smell. The presence of mucus in the nose. A lot of mucus will reduce the sensitivity of the nose.

16 Human ear A human ear has three main part.
the outer ear, filled with air. The middle ear, filled with air. The inner ear, filled with liquid

17 Human ear





22 Try to answer

23 Test

OUTER EAR Pinna collects and directs sound waves into the ear canal. ear canal / auditory canal transmits sound waves to the eardrum. Eardrum vibrates and transmits sound waves to the ossicles. MIDDLE EAR Ossicles intensify the vibrations of the sound waves by 22 times before transmitting to the oval window. Eustachian tube balances the air pressure at both side of the eardrum. oval window transmits sound vibrations from the middle ear to the inner ear. INNER EAR Cochlea transforms sound vibrations into impulses. semicircular canals balance the body position. auditory nerves send messages to the brain which interprets the messages as sound.

25 Stereophonic hearing Stereophonic hearing is hearing using both ears.
The advantages of stereophonic hearing: enables the direction of the source of hearing to be detected more accurately. This is because the ear nearer the source of sound receives sound louder and earlier than the other ear. Animals that have stereophonic sound can detect the presence of preys and predators more quickly.

26 Properties of sound sound can transferred through; solids liquids
gases cannot be transferred through in vacuum. (particles in solids and liquids are closer each other compared to the molecules in gases. Vacuum is space that does not have any particles.)

27 ANIMAL Frekuansi snake 100-800Hz frog 50-10 000Hz dog 10-50 000Hz cat
The range of frequencies of hearing in man is 20 Hz until Hz. The following table shows the range of frequencies of hearing of several animals: Different people have different limitations of hearing. ANIMAL Frekuansi snake Hz frog Hz dog Hz cat Hz bat Hz grasshopper Hz whale 10-50Hz Human 20hz – hz

28 Experiment PKBS F2

29 Reflection and absorption of sound
Sound can be reflected or absorbed by the surface of an object. The sound reflected repeatedly from one surface is known as echo. Surfaces that are smooth, even and hard are good sound reflectors and produce loud echo. For examples, concrete, plank, metal and mirror Surfaces that are rough, hollow and soft are good sound absorbers and produce weak echo. For examples cloth, sponge, cork, rubber, carpet and cushion.

30 To overcome the limitations of hearing, we use
the stethoscope enables doctor to detect the soft heartbeats of patients. ii. hearing aids collects sound signals before being sent to the middle ear. iii. amplifier boosts weak sound signals.

31 Human eye choroid

32 Human eye

33 Human eye

34 Human eye





Structure / characteristic Function Sclera Maintains the shape of the eyeball Protects the eyeball cornea rybb Choroids Conjunctiva iris pupil Lens PMR 04 Transparent and elastic convex lens Refracts and focuses light onto the retina. ciliary muscle supportive ligament vitreous humour aqueous humour Retina PMR 2011 optic nerve

40 Human eye Yellow spot

41 Daily activities bright room dark room iris pupil

42 Daily activities


44 Stereoscopic vision Disadvantages - using both eyes. predator
See three-dimensional pictures of objects. Enables more accurate estimation of distance and position. Disadvantages A narrow vision field.

45 Monocular vision. using only one eye. prey Advantages
having a wide vision field. Disadvantages cannot estimate distance accurately.


47 Experiment Textbook pages 20

48 Mechanism of Sight PMR 03, 07 ii. focusing distant object.
The eye lens focuses the image onto the retina by changing the thickness of the eye lens. The thickness of the lens is changed by the cilliarry muscles. i.Focusing near objects To focus near objects onto the retina, the cilliarry muscles contract. The eye lens become thicker. ii. focusing distant object. To focus distant objects onto the retina, the cilliarry muscles relax. The eye lens becomes thinner.



51 Reflection of light Contoh, BOMBA, POLIS Rough surface
Flat, shiny, smooth


53 Device used concept reflection
Kalaideskop – tak guna concept reflection

54 Reflection of light

55 Refraction of light

56 Refraction of light

57 Refraction of light

58 Smooth, shiny, flat A D B C E F H G I J

59 Less dense denser

60 Short sightedness Causes: Eye ball is too big Eye lens is to thick.
Correction: Wearing concave lens

61 Long sightedness Causes: Eye ball is too small Eye lens is to thin.
Correction: Wearing convex lens


63 Comparison between SS and LS




67 Astigmatism Light is refracted to multiple areas of the retina.
This defect can be overcome by wearing glasses with cylindrical lenses or contact lens or by surgery.

68 Astigmatism


70 Experiment short sightedness & long sightedness
Instructions First, I want you to form groups of four. In your group, discuss why some people wear glasses Next, I want you to look at the first picture on the screen Click and drag the picture from left to right. Observe what happens to the image Then, repeat the activity on the second and third pictures

71 Questions Why do some people wear glasses? What is the cause of short sightedness? Where does the image fall when a short sighted person look at a far object? What kind of lens is used to correct short sightedness?

72 Formative Assessment Types of Defects Able to see close/near objects
(clear/blur) Able to see distant object (clear/blur) Types of lens used to correct defects 1) Short sightedness 2) Long sightedness 3) Astigmatism

73 Complete the diagram Short sightedness Long sightedness
The image falls _______ of the retina The image falls ______of the retina

74 Short sightedness & long sightedness


76 Optical illusion


78 Optical illusion


80 Blind spot The blind spot is a spot on the retina of the eye that cannot detect light stimulus. The image of the object formed at the blind spot cannot be seen by the eye because there are no light-sensitive cells (photoreceptors) at the blind spot.


82 Tropism Plant response to external stimulus
Plants grow towards stimulus called positive tropism Plants grow away from stimulus called negative tropism


84 Anhydrous Calcium chloride

85 Phototropism Response to light.

86 Hydrotropism Response to water

87 Geotropism Response to gravity

88 Thigmotropism Response to touch move towards – to obtain support

89 Nastic movement Response to touch Move - run away



92 Penutup 1. Baca Surah Al-`Ashr 2. Tasbih Kifarah.

93 The end


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