(a) Explain briefly how the human ear carries out its function of balancing. (b) (i) make a drawing 8 cm - 10 cm long of the structure of the human ear and ...

Answer Details

(a) The human ear is responsible for maintaining balance, also known as vestibular function. This is achieved through the vestibular system, which is comprised of three semi-circular canals and the utricle and saccule in the inner ear. These organs work together to detect changes in head position and movements, and to send signals to the brain to help maintain balance.

(b) (i) Here is a labeled drawing of the structure of the human ear:

 __________
|  Pinna   |
|__________|
|  Auditory|
|  canal   |
|__________|
| Tympanic |
|  membrane|
|__________|
|  Malleus |
|__________|
|  Incus   |
|__________|
|  Stapes  |
|__________|
| Oval window|
|___________|
| Cochlea   |

Pinna: The outer visible part of the ear
Auditory canal: A narrow passage that leads to the tympanic membrane
Tympanic membrane: Also known as the eardrum, it vibrates in response to sound waves
Malleus: The first of three small bones in the middle ear, it is attached to the tympanic membrane
Incus: The second of three small bones in the middle ear, it transmits vibrations from the malleus to the stapes
Stapes: The third and smallest of the three bones in the middle ear, it transmits vibrations from the incus to the oval window
Oval window: An opening in the inner ear that leads to the cochlea
Cochlea: A spiral-shaped organ in the inner ear that converts vibrations into nerve impulses that are sent to the brain

(b) (ii) The middle ear is the space behind the tympanic membrane and is connected to the back of the throat by the Eustachian tube. The middle ear contains three small bones, the malleus, incus, and stapes, which are collectively known as the ossicles. These bones work together to transmit sound vibrations from the tympanic membrane to the inner ear. The middle ear also contains the tensor tympani muscle and the stapedius muscle, which help to regulate the volume of sound entering the inner ear.