By the end of this lesson you should be able to:
- Define sense organs as groups of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicals
- Identify the structures of the eye, limited to cornea, iris, pupil, lens, retina, optic nerve and blind spot
- Describe the function of each part of the eye, limited to:
– cornea – refracts light
– iris – controls how much light enters pupil
– lens – focuses light onto retina
– retina – contains light receptors, some sensitive to light of different colours
– optic nerve – carries impulses to the brain
- Explain the pupil reflex in terms of light intensity and pupil diameter only
- Explain accommodation to view near and distant objects
Activities: Pair work
- Eye structure: Play this animation to study the parts of the eye
- Eye functions: Play this animation to study the eye functions. Identify the structures on the diagram from exercise 2, page 9 in the booklet and write down the functions beside the structures.
- Now you are able to answer exercise 3 from page 9 in the booklet.
- How the eye works: Read and play the animation from this webpage
- Answer the following questions from page 9 and 10 in the booklet:
-4) c and d
– 2) a
6. The PUPIL REFLEX: -Search in the internet a short video about pupil reflex.
– Draw a flow chart explaining the reflex (stimulus, receptors, coordinator, effectors, effect and response.
7. Answer exercise 1, page 9 in the booklet.
8. ACCOMMODATION: Read and play the animations to learn how the eye focuses on a nearby and a distant object.
9. Answer questions 2) b and 4) a from pages 9-10.
10. Integrating the eye and the nervous system: Use your knowledge to answer question 5) page 10. By now, you should be able to solve it by yourself!!