9
Question The figure given below shows the principal parts of a human ear. Study the diagram and answer the following questions.
(a) Label the parts 1 to 8.
(b) State the role of parts 6, 7 and 8.
(c) Why is it harmful to use a sharp object to remove ear wax? Mention the number and name of the part involved.
(a) The labelled parts are:
- 1 → External ear (pinna)
- 2 → Ear drum (tympanum)
- 3 → Auditory canal
- 4 → Malleus
- 5 → Semicircular canals
- 6 → Cochlea
- 7 → Auditory nerve
- 8 → Eustachian tube
(b) Part 6 (Cochlea) — It contains sensory cells for hearing.
Part 7 (Auditory nerve) — It transmits impulse of hearing to the brain.
Part 8 (Eustachian tube) — It equalizes air pressure on both the sides of the tympanum.
(c) It is harmful to use a sharp object to remove ear wax as it can rupture the ear drum.
The part involved is part 2 — Ear drum (tympanum).