47246929 24641593 Science Folio Form 2 the World Through Our Senses
-
Upload
megat-ezzad-aiman -
Category
Documents
-
view
264 -
download
0
Transcript of 47246929 24641593 Science Folio Form 2 the World Through Our Senses
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
1/19
MRSM PDRM
Name : Muhammad Fikri bin Ahmad Fauzi
College no. : 29082Class :
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
2/19
Contents
Contents Page
Appreciation 1
The world through our senses 2
Sense organ ability 3
The human nervous system 4,5
Skin 6,7
Tongue 8,9
Nose 10.11
Ears 12,13
Eyes 14,15
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
3/19
I want to say thank you to my parents for
supporting me on financial and moral.
Because of that, I can finish my folio verywell. Lastly, I want to say thank you to my
friends that always help me and also share
some information. Not forgotten for all
parties that involved. Thank you very much.
The World Through Our Senses
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
4/19
Our senses detect stimuli and we respond.
Human have receptors orsense organs such as:
SKIN - responds to touch, pressure, pain, heat and cold.
TONGUE - responds to chemical in our food and drink. It gives us
our sense of taste
NOSE - responds to chemical in the air. It gives us our sense of smell.
EARS - respond to sound vibrations and movements. They give us our
sense of hearing and our balance.
EYES - respond to light rays. They give us our sense of sight.
1
SENSE ORGANS ABILITY
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
5/19
Sensory organ Stimuli detected Main function
(a) Skin Touch, pressure, pain,heat, cold Organ for touch
(b) Nose Chemicals Organ for smell
(c) Tongue Chemicals Organ for taste
(d) Ear Sound Organ for hearing
(e) Eye Light Organ for sight
2
The Human Nervous System
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
6/19
1. The nervous system is responsible for detecting stimuli and changes in
the environment and sending the information to the brain for
interpretations.
2. The brain then sends out instructions to the relevant parts of the body
for action to be taken.
3. The information and instructions are sent out in the form of nervous
impulses along nerves.
4. The nervous system consists of the brain, the spinal cord and the
nerves.
5. The brain and the spinal cord form the central nervous system.
6. The nerves which send nervous impulses from the sensory organs or
receptors to the brain are called the sensory nerves.
7. The nerves which carry nervous system from the central nervous
system to the muscle or glands for carrying out the responses are
called the motor nerves.
3
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
7/19
Nervous system
4
Skin
Nervous
System
Central nervous
system Nerves
BrainSpinal
Cord
Sensory
nerves
Motor
Nerves
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
8/19
1. The skin is made up of two layers- the epidermis and the dermis.
2. The epidermis is a very thin layer of dead cells which protects the
surface of the body.
3. The dermis is a layer consisting of structures such as living cells,
blood capillaries, sweat glands, nerves and nerve ending.
4. The skin is a sense organ helping the body to know what is happening
in its surrounding.
5. The nerve endings or receptors in the skin detect stimuli.
6. The sensitivity of the skin depends on two factors:
(a) The thickness of the epidermis - the thinner the epidermis,
the more sensitive is the skin.
(b) The concentration of the receptors the more receptors inthe skin, the more sensitive is the skin.
5
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
9/19
-Pain receptors are at the skinsurface. They are branched and
respond to intense stimuli.
-Some touch receptors are
attached to the base of our hair. So
you can feel it they are being
pulled.
-Pressure receptors are in the
fatty layer. It is used to detectpressure exerted on the skin.
-Heat receptors are located below
the epidermis. It detects heat or any
rise of temperature.
-Cold receptors are also located
below the epidermis. It detects a cold substances or any fall in temperature.
6
Tongue
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
10/19
1. Your senses of taste and smell are closely linked. They are both
chemical senses.
2. What things can you taste?
-You can only taste sweet, sour, bitter, and salty things. People think
that they can taste other things but they are actually using their sense
of smell.
3. The sensors that give you your sense of taste are found in little
grooves on your tongue. They are call taste buds.
Each taste bud can only taste one taste.
4. The different types of taste buds are found in particular areas on
the tongue.
5. The taste buds send nervous impulses along the nerves to the brain for
its interpretation.
6. When food is placed in the mouth, the saliva dissolves the food and
the chemicals stimulate the taste buds.
7
Nervous pathway for detecting taste:
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
11/19
Food(stimuli) Saliva dissolves food Chemical in food stimulate taste
buds Taste buds send impulses to brain The brain interprets the
impulses
o Diffe
rent areas of the tongue are especially sensitive to different taste
8
Nose
Our nose also senses chemical but it is thousands of time more sensitive than
your sense of taste.
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
12/19
Smells are chemical in the air.
The chemical dissolve in the moist lining of your nose.
They stimulate sensors in your nose to send impulses to the brain.
The brain interprets these impulses as different smells.
The nasal cavities have glands which produce a sticky fluid called mucus.
A person having a cold cannot smell well. This is because the sensory cells
are covered with a lot mucus and not much chemicals can reach and
stimulate the sensory cells.
The nervous pathway can be summarized as follows:
Chemical enter the nose Chemical dissolves in mucus Chemical
stimulate the sensory cells The sensory cells produce nervous impulses
Nervous impulses are sent along the nerves to the brain The brain
interprets the impulses as a certain smell
9
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
13/19
10
Ears
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
14/19
The air around us is full of sound waves.
You ears work by converting these sound waves into nerve impulses.
This show it happens:
The outer part of your ear funnels the sound waves into the ear canal
The sound waves travel along the ear canal to the eardrum.
The eardrum starts to vibrate when sound waves hit it
The vibrations are passed on to 3 little bones called the ossicles
The ossicles pass the vibrations on to the inner eardrum or oval
window
When oval window vibrates it causes fluid in the cochlea to move
Inside the cochlea are lots of tiny, sensory hairs. Movement of the
fluid sets these
hairs vibrating. They send off nerve impulses to the brain
The brain interprets these impulses as sounds
11
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
15/19
12
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
16/19
Eye
The eye is a sensory organ for light. We see things with our eyes.
Each eyeball is situated in a socket within the skull.
Each eyeball is moved by three pairs of eye muscle.
The front of each eye is protected by an eye lid.
The eye is washed by tears produced by tear glands.
A duct drains the tears from the eye to the throat.
The pupil (hole) in the centre of the eye allows light to enter the eye.
The colored part of the eye called the iris is a continuation of the choroids
The white of the eye is a continuation of the sclerotic.
The eye is made up of many parts, and each part is designed to help the
eye to see.
The nervous pathway is as follow:
Corneaaqueous humorpupileye lens vitreous
Humorretinaoptic nervebrain
13
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
17/19
The structure of the eye
14
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
18/19
Defects of Vision
Long-sightedness
Short-sightedness
Astigmatism
Color blindness
Optical illusion
Blind spot
There are two kinds of vision:
Stereoscopic vision
Monocular vision
.
15
-
8/3/2019 47246929 24641593 Science Folio Form 2 the World Through Our Senses
19/19