Ears

Question 1

Auricle (Labels)

Answer 1

• Surrounds the auditory canal opening

- “Eat” part

Question 2

Auditory Canal (External Acoustic Meatus)

Answer 2

• Narrow chamber in the temporal bone
• Lined with skin and ceruminous (wax) glands
• Ends at the tympanic membrane

Question 3

Tympanic Membrane

Answer 3

• Hit w/ sound waves from auditory canal

- Vibrates w/ sound hits

Question 4

Hammer (Malleus)

Answer 4

• Sends vibration from eardrum to anvil

- Part of the ossicles

Question 5

Anvil (Incus)

Answer 5

• Sends vibration to stirrup

- Part of the ossicles

Question 6

Stirrup (Stapes)

Answer 6

• Sends vibration to the inner ear

- Part of the ossicles

Question 7

Vestibulocochlear Nerve

Answer 7

• both hearing and balance and brings information from the inner ear to the brain
• A human’s sense of equilibrium is determined by this nerve

Question 8

Semicircular Canals

Answer 8

-Responds to rotational movements (angular acceleration)

Question 9

Oval Window

Answer 9

• Opening in the middle ear

- Release pressure in the ear

Question 10

Cochlea

Answer 10

• cavity of the inner ear resembling a snail shell

- houses the hearing receptor

Question 11

Vestibule

Answer 11

• Between semicircular canal & cochlea

- Responds to changes in the position with respect to gravity

Question 12

Round Window

Answer 12

• Opening in the middle ear

- Release pressure in ear

Question 13

Pharyngotympanic tube

Answer 13

• tube that connects the middle ear and the pharynx

- allows pressure to be equalized on both sides of the eardrum

Question 14

Trace Sound Through the Ear

Answer 14

• Auricle(pinna)
  
  • Auditory Canal
  • Tympanic Membrane (eardrum)
  • Malleus
  • Incus
  • Stapes
  • Semicircular canals
  • Vestibule
  • Cochlea

Question 15

Outer Ear

Answer 15

• Auricle

- Auditory Canal

Question 16

Middle Ear

Answer 16

• Tympanic Membrane (eardrum)
• Anvil (Incus)
• Hammer (malleus)
• Stirrup (Stapes)

Question 17

Inner Ear

Answer 17

• Semicircular Canal
• Cochlea
• Vestibule

Question 18

Organ of Corti

Answer 18

• Located within the cochlea
  - Receptors = hair cells on the basilar membrane
  - Gel-like tectorial membrane is capable of bending hair cells
  - Cochlear nerve attached to hair cells transmits nerve impulses to auditory cortex on temporal lobe

Question 19

Mechanisms of Hearing

Answer 19

• Vibrations from sound waves move tectorial membrane
• Hair cells are bent by the membrane
• An action potential starts in the cochlear nerve
• Continued stimulation can lead to adaptation

Question 20

Organs of Equilibrium

Answer 20

• Equilibrium receptors of the inner ear are called the vestibular apparatus
  
  • Vestibular apparatus has two functional parts
    
    • Static
    • Dynamic

Question 21

Static Equilibrium (Nonmoving)

Answer 21

• Maculae—receptors in the vestibule
  - Report on the position of the head
  - Send information via the vestibular nerve
• Anatomy of the maculae
  - Hair cells are embedded in the otolithic membrane
  - Otoliths (tiny stones) float in a gel around the hair cells
  - Movements cause otoliths to bend the hair cells

Question 22

Dynamic Equilibrium

Answer 22

• Crista ampullaris—receptors in the semicircular canals
  - Tuft of hair cells
  - Cupula (gelatinous cap) covers the hair cells

        - Action of angular head movements
            - The cupula stimulates the hair cells
            - An impulse is sent via the vestibular nerve to the cerebellum