ETV “Junior Secondary Science” Programme
The Brain and the Senses
Teachers’ Notes
Target Audience
Secondary 1 - 3
Duration
20 minutes
Production Aim
This programme is a teaching resource produced especially for enriching the classroom teaching in S2 level of the Syllabus for Science (Secondary 1 – 3) prepared by the Curriculum Development Council (1998).
The content of the programme serves to illustrate the following parts of the Syllabus：
Unit 11 Sensing the Environment
Topic 11.8 – Senses of smell, taste & touch : ‘Our sense of smell affects our sense of taste’ and ‘Our skin is not reliable in detecting hot and cold’ of the Core Content, Topic 11.9 – The brain and our senses, Topic 11.10 – Responses to stimuli, and Topic 11.11 – Effects of drugs and solvents on our senses : ‘Drugs and solvents affect our judgments and responses’ of the Key Points.
Key Points
1. An introduction to the responses of human body to stimuli.
2. An introduction to the structure and function the brain.
3. An introduction to our nervous system.
4. An introduction to some common perceptions, and
5. An introduction to the damage of drug-abuse on our brain and body.
Content Outline
This programme is divisible into 8 segments as follows:
1. Control Centre in Our Body
Using the Castle Peak power station as an example, the film shows the importance of a control centre, and points out that there is also a control centre in our body. A baby’s behaviour is used to show that we have the instinct to react to stimuli. Through experiments, the films shows that a baby will express himself when his body receives stimuli; and that comparison in reaction time indicates that our control centre is located in our head – the brain.
2. Nervous system
A dissected guinea pig is used to show the structure and relationship between the brain, the spinal cord and the nerves of a mammal. The film points out that this is the nervous system of the animal, and that it is similar to our own. Graphics are then used to show the structure and function of the nervous system of human.
3. Structure and Function of the Human Brain
With the help of a model, the film shows the structure of the human brain as consisting of the cerebrum, the cerebellum and the brain stem.
- cerebrum: divided into two halves and each further divided horizontally into front and back halves. Magnetic resonance shows that the cerebrum is divided into functional areas: the back is associated with sight, the two sides with hearing, the front with reasoning, the posterior part of the top with touch, and the anterior part of the top with muscle movements.
- cerebellum: shaped like a walnut; controls the movements of the voluntary muscles associated with body posture and movement.
- brain stem: connected to the spinal cord; controls various physiological processes of a number of vital organs.
4. Reinforcement of Senses
Daily examples are used to show that our sense of taste may be affected by our sense of smell; graphics are then used to explain the reason.
5. Illusion
Pictures are showed to the students to let them experience illusion. The film further shows that illusion may be caused by objective factors as well as by subjective view.
6. Are Our Senses Reliable?
Viewing at selected pictures shows that our senses are not as reliable as we think they are; instruments are thus necessary to help when doing scientific observations and measurements.
7. Hallucination
Film clips are used to show what hallucinations look like. Dr. Ben CHEUNG of the Substance Abuse Assessment Unit, Hospital Authority, helped with further film clips, introduces the definition and types of hallucination. Dr. CHEUNG further points out that there are three factors causing hallucination: heredity, emotional disturbance and effects from drugs.
8. Drug Abuse is Damaging
Dr. Ben CHEUNG of the Substance Abuse Assessment Unit, Hospital Authority points out that from medical study, even a one-off abuse of drugs may cause long-term effect on the brain, causing abnormal activities. The study shows further that a short-term drug abuser will have his nerve endings losing function, while a long-term one will have the nerve endings decaying or the nerves having abnormal out-growths, causing interference to information transmission.
Suggestions for Utilization
1. The entire programme may be shown to the students in one session to serve as a way of consolidation after the teaching of the topic ‘Sensing the Environment’.
2. The programme can also be shown in a S4/5 Biology/Human Biology lesson as a starting point of the lesson, or as a way to motivate students.
3. Teachers may use segments 7 and 8 of the programme as background information in their lessons on drug education.
4. Teachers may spend 5 to 10 minutes before the show to lead a discussion with students. After the show, teachers may spend another 10 to 15 minutes discussing with students in order to consolidate the concepts and principles illustrated in the programme. Teachers are advised to refer to the Suggested Activities listed below.
Suggested Activities
(The following activities are suggested for teachers’ reference only. Teachers may wish to select suitable activities according to students’ abilities, the learning environment of the class, and the teaching time available.)
Preparation before viewing the programme
Teachers may first ask students some simple questions about the brain and the nervous system. Teachers need not elaborate too much, but ask the students to concentrate on the programme.
Activities after viewing the programme
1. Teachers may let the students look at a number of pictures that would cause illusion, and ask how they perceive these pictures.
2. Teachers may divide the students into groups of three. The students are to take turns in being blindfolded and testing with their fingers the temperature of the water in different beakers. The groups are to discuss and summarize their results, followed by a discussion of the whole class on the reliability of human senses.
3. Teachers may use some recent newspaper cuttings on cases of drug abuse and information from segment 8 of the programme to lead the students into a debate on the damages on the human body caused by drug abuse.
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