Public facilities specially designed for the visually-impaired braille map showing the layout of the MTR station

vibrates in different patterns according to the states of the lights traffic light tactile unit

audible device gives out sound signals according to the states of the lights traffic light

1 How do we detect stimuli in our surroundings?

2 Which senses do the visually-impaired depend on when they are using the above facilities?

3 Is our sense always reliable?

11.1 The importance of sensing the environment

11.1 The importance of sensing the environment Living things are able to detect and respond to changes in the environment.

When it smells the scent of nectar… 11.1 The importance of sensing the environment When it smells the scent of nectar…

When rabbits hear their enemies coming … 11.1 The importance of sensing the environment When rabbits hear their enemies coming … Run away!

receptors (感受器) of a sense organ (感覺器官) 11.1 The importance of sensing the environment stimuli (刺激) detected by receptors (感受器) of a sense organ (感覺器官) send messages through nerves (神經) to brain produces sense (感覺)

Touch (觸覺) We have five senses. Hearing (聽覺) Smell (嗅覺) Senses Sight 11.1 The importance of sensing the environment Touch (觸覺) We have five senses. Hearing (聽覺) Smell (嗅覺) Senses Sight (視覺) Taste (味覺)

11.1 Sense organs and senses 1 Sight 11.1 The importance of sensing the environment 11.1 Sense organs and senses 1 Sight Our ______ can detect light in the environment. eyes

11.1 2 Hearing Our ______ can detect sound in the environment. ears 11.1 The importance of sensing the environment 11.1 2 Hearing Our ______ can detect sound in the environment. ears

11.1 3 Touch Our ______ can detect hot, cold, pressure and pain. skin 11.1 The importance of sensing the environment 11.1 3 Touch Our ______ can detect hot, cold, pressure and pain. skin

11.1 4 Smell Our ______ can detect the smells of substances. nose 11.1 The importance of sensing the environment 11.1 4 Smell Our ______ can detect the smells of substances. nose

11.1 5 Taste Our ________ can detect the taste of food. tongue 11.1 The importance of sensing the environment 11.1 5 Taste Our ________ can detect the taste of food. tongue

Skin Sense organs Ears Nose Eyes Tongue 11.1 The importance of sensing the environment Skin We have five sense organs. Sense organs Ears Nose Eyes Tongue

detect stimuli, leading to the sense of 11.1 The importance of sensing the environment Eyes Ears Skin Nose Tongue detect stimuli, leading to the sense of sight hearing touch smell taste

Living things use their sense organs to detect environmental stimuli. 11.1 The importance of sensing the environment Living things use their sense organs to detect environmental stimuli. The ability to detect and respond to stimuli is important for survival.

The stimuli which our sense organs detect and the senses produced: 11.1 The importance of sensing the environment The stimuli which our sense organs detect and the senses produced:

Chemicals in food and drinks Taste 11.1 The importance of sensing the environment Sense organ The stimulus the sense organ detects Eye Light Sight Ear Sound Hearing Skin Hot, cold, pressure, pain Touch Nose Chemicals in air Smell Tongue Chemicals in food and drinks Taste

1 Stimulus Sense organ Sense a Light from TV Eye Sight 23 11.1 The importance of sensing the environment 1 Stimulus Sense organ Sense a Light from TV Eye Sight

1 Stimulus Sense organ Sense b Sound from TV Ear Hearing 24 11.1 The importance of sensing the environment 1 Stimulus Sense organ Sense b Sound from TV Ear Hearing

1 Stimulus Sense organ Sense c Sweetness of hot chocolate Tongue Taste 25 11.1 The importance of sensing the environment 1 Stimulus Sense organ Sense c Sweetness of hot chocolate Tongue Taste

1 Stimulus Sense organ Sense d Smell of hot chocolate Nose Smell 26 11.1 The importance of sensing the environment 1 Stimulus Sense organ Sense d Smell of hot chocolate Nose Smell

1 Excellent! Stimulus Sense organ Sense e Softness of cushion Skin 27 11.1 The importance of sensing the environment 1 Stimulus Sense organ Sense e Softness of cushion Skin Touch Excellent!