Find out from dictionary the meaning of:

Hearing - Sense -

Sense organ - Sight -

Smell- Stimuli-

Taste- Touch-

Skin- Nose-

Tongue- Ears-

Eyes- Detect-

Pressure- Light intensity-

Response- Brain

Nerve- Sensitive-

Spinal cord- Pathway

Receptors- Swat-

Sweat- Pore

Gland- Pain

Epidermis Dermis

Impulses External stimuli

Nerve ending Sense of touch

Cold Heat

1.1 Sensory Organ and Their Functions

1. Living organisms have sensory organ.

2. These sensory organs help us to detect changes in environment.

3. Different sensory organs will detect different stimuli.

4. Stimuli are changes that occur in environment.

5. Senses are the ability of sensory organs to detect stimuli.

a. The skin detects touch, pressure, heat or cold

b. The nose detects smell

c. The ear detecst sound

d. The eye observes by seeing

e. The tongue detects taste

5 different type of senses in human

1. The following activities was carried out.a. A tap was touched with my fingersb. The cork was removed from the test tube and the ammonia was smelt in it.c. Some sugar was put on the tip of my tongued. The table was knocked with a ruler.e. The blackboard was looked.

2. The result was recorded in table 1.13. The relation between the five senses, sense organs and stimuli was shown in table 1.2

Result:

Activity Effect

a. The fingers feel cold

b. The nose detect a stingy smell

c. A tongue detect a sweet taste.

d. A sound is heard.

e. The writing on the blackboard can be seen.

Table 1.1

Activity Sense Sense organ

Stimuli

a. Touch Skin Cold

b. Smell Nose Chemical

c. Taste Tongue Chemical

d. Hearing Ear Sound

e. Sight Eye Light

Table 1.2

Conclusion:There is a relation between the five senses, sense organ And stimuli.

The relation between the stimuli, the five senses and sense organs.

Activity Sense Sense organ

Stimuli

a. Touch Skin Cold

b. Smell Nose Chemical

c. Taste Tongue Chemical

d. Hearing Ear Sound

e. Sight Eye Light

Eye - Sensitive to light

Ear- Sensitive to sound

Tongue- Sensitive to chemicals in food and liquids (taste)

Skin- Sensitive to touch

Nose- Sensitive to chemical in the air (smell)

Respond to stimuli

Response to stimuli

1.When stimulus is detected by a sensory organ, information is sent to the brain.

2. A suitable response will then be produced.

3. The brain is the control centre that control all the action. 4. The brain is linked to all parts of body by nerves.

5. Nerve send signals to brain when get response.

6. Nerve send signals from sense organ to brain.

7. When the brain get message it will interpret and produce a suitable respond

Stimulus Sensory organ Nerve Brain

NervesResponse

Skin nerve

Brain nerve

Exercise:How do we detect the changes that occur in environment? (Bagaimanakah kamu mengesan perubahan yang berlaku pada alam sekeliling?

• Complete the table below by giving the stimulus for each activities.

Activity Stimulus

A Stepping on a thumbtack

B Eating ice cream

C Grilling satay

D Looking at a rainbow

E Smelling food

3. Show the sequence of events involved in detecting a stimulus.

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