Chapture 12 - Mechanoreceptors

Question 0

What is the Pinna , what is it made of and how Is its structure helpful

Answer 0

The outside flap of the ear
Made of skin and cartilage
Shaped in a way that enhances sound vibration and focuses them into the ear

Question 1

What does the outer ear consist of?

Answer 1

Pinna and auditory canal

Question 2

What is the auditory canal, and what is it’s function?

Answer 2

A tube that leads to the eardrum in the middle ear.
It amplifies sound waves.
Hairs inside the auditory canal protects it from dust , bacteria, insects or foreign objects

Question 3

What does the middle ear consists of ?

Answer 3

Tympanum
Ossicles
Oval window
Eustachian tube

Question 4

What is the tympanum

Answer 4

Aka : ear drum or tympanic membrane

Round elastic structure that vibrates in response to sound waves . It’s vibrations are then amplified and passed on to the ossicles

Question 5

What are the ossicles?

Answer 5

Three tiny interconnected bones in the middle ear.
Each bone acts as a lever for the next, the movement in one results in a larger movement in the other. As a result the strength in vibration is amplified as they pass from the:
Malleus (hammer)
Incus (anvil)
Stapes (stirrup)

Question 6

What does the inner ear consist of ?

Answer 6

The inner ear consists of 3 interconnecting structures: the semicircular canals, the vestibule, and the cochlea.

Question 7

Which part of the inner ear contains the sensors for balance?

Answer 7

Semicircular Canal and vestibule

Question 8

What part of the inner ear is used for hearing?

Answer 8

Cochlea

Question 9

What happens in the cochlea?

Answer 9

Mechanical energy of sound is converted into the electrochemical impulses that are then transmitted to the brain

Question 10

What does the middle chamber of the Cochlea contain ?

Answer 10

Organ of corti

Question 11

What is along the base of the Organ of corti and what is attached ?

Answer 11

Basilar membrane , it is where the the mechanireceptors known as hair cells are attached .

Question 12

What sticks out at the top of the hair cells?

Answer 12

Stereosilla

Question 13

What is attached to the stereosilla?

Answer 13

Tectorial membrane

Question 14

Describe the travel of sound waves through the ear.

Answer 14

Sound waves enter the ear through the auditory canal, then vibrate the tympanum (eardrum) , these vibrations are passed onto the three tiny bones known as the ossicles, each bone acts as a lever for the next amplifying the vibrations, first the malleus, then incus, then stapes concentrates the vibration into an opening in the wall of the inner ear called the oval window, and creates pressure waves in the fluid of the cochlea , these pressure waves then make the basilar membrane move up and down, which cause the stereocilia of the hair cells to bend against the tectorial membrane… The hair cells which synapse with the nerve fivers of the auditory nerve sense the bending of the stereocilla and relay the message to the nerves .