Unit 1: Anatomy Of The Ear & Hearing

Question 1

Mechanoreception (hearing and balance):

Answer 1

•hearing is associated with fluctuations in air pressure, called sound waves. Mechanoreceptors in the fluid-filled inner ear convert the energy of sound waves into electrochemical impulses which the brain perceives as sound.

•balance is associated with movement. Mechanoreceptors in the ear convert the energy of liquid movement into electrochemical impulses.

Question 2

Anatomy of the ear & hearing:

Answer 2

•sound waves are directed by pinna to the auditory canal, where they strike the tympanum (ear drum).

•sound waves push against the tympanum, and vibrations are passed on and amplified by the three ossicles (bones).

•vibrations are concentrated on the oval window, causing changes in pressure within the organs of the inner ear.

•pressure changes stimulate hair cells found in the organ of corti within the coiled cochlea. This generates an action potential in the auditory nerve that is sent to the temporal lobe.

Question 3

Structures of the ear not associated with hearing:

Answer 3

•pressure changes cause waves in the fluid of the semicircular canals which act to maintain balance.
•the eustachean tube connects to the throat, allowing air pressure to equalize.

Question 4

Chemoreception (taste):

Answer 4

-the tongue contains chemoreceptors that allow us to taste substances entering the mouth. Impulses from taste buds, where chemoreceptors are located, then travel to the parietal lobe.

Question 5

Chemoreception smell:

Answer 5

•humans can distinguish between over 10,000 different odours. Each of these odour particles is thought to fit like a lock & key into specific chemoreceptors which line the nasal cavity, known as olfactory cells.
-olfactory cells transmit signals to the olfactory bulb in the brain.

Question 6

Proprioception:

Answer 6

-perception of movement and body position in space (muscles).

Question 7

Tympanum is also:

Answer 7

-tympanic membrane.
-(eardrum).