Ear

Front 1

human ear consists of the three major parts?

Back 1

1) external ear
2) middle ear cavity
3) inner ear.

Front 2

external ear includes the?

Back 2

1) auricle
2) external ear canal
3) tympanic membrane.

Front 3

middle ear cavity

Back 3

air-filled chamber which contains three bony ossicles:
1) malleus
2) incus
3) stapes

Front 4

inner ear contains the?

Back 4

1) cochlea
2) vestibule
3) semicircular canals
4) plus their respective membranous components.

Front 5

ceruminous glands

Back 5

Lateral one-third of external ear canal contains ceruminous glands

- produce cerumen or ear wax; an insect repellent

Front 6

External Ear Canal (external auditory meatus)

Back 6

extends from the auricle to the tympanic membrane.

Front 7

Nerves of the auricle (pinna) –

Back 7

a. cutaneous innervation by auriculotemporal nerve (CN V3)
b. facial nerve (CN VII)
c. glossopharyngeal nerve (CN IX)
d. vagus nerve (CN X) plus the great auricular nerve (branch of the cervical plexus).

Front 8

Malleus

Back 8

- attached to the tympanic membrane
- tensor tympani muscle inserts on its handle (functions to dampen or attenuate vibration of tympanic membrane);
- tensor tympani (contracts when exposed to loud noice by slowing down the vibration of the malleus) is innervated by CN V3.

Front 9

tensor tympani muscle

Back 9

1) inserts on its handle (functions to dampen or attenuate vibration of tympanic membrane);
2) Innervated by the CN V3

Front 10

Incus

Back 10

articulates with malleus and stapes.

Front 11

Stapes

Back 11

- its footplate fits into the oval window;
- its head articulates with the incus;
- stapedius muscle (smallest muscle in body) inserts into its neck (functions to prevent excessive movement); is innervated by CN VII.

Front 12

stapedius muscle

Back 12

- (smallest muscle in body)
- inserts into its neck (functions to prevent excessive movement);
- innervated by CN VII.

Front 13

Mastoid antrum

Back 13

(opening that connects the middle ear and the air cells in the mastoid process) and mastoid air cells

Front 14

Inflamation of the mastoid air cells

Back 14

mastoiditis, which lays next to the posterior cranial fossa. Chronic infection can causes thinning of bone in this area, to such an extent that the hole may develop into the cranial cavity.

Front 15

Bony Labyrinth consists of?

Back 15

1) Cochlea
2) Vestibule
3) Semicircular Canals

Front 16

Membranous Labyrinth consists of?

Back 16

1. Cochlear duct –
2. Utricle –
3. Saccule –

Front 17

Cochlea

Back 17

shaped like a snail shell; contains organ of hearing (Organ of Corti).

Front 18

Organ of Corti lies within what structure?

Back 18

Cochlea

Front 19

Vestibule contains what membranous structures?

Back 19

1) utricle
2) saccule (apparatus for balance).

Front 20

Semicircular Canals

Back 20

named according to their relative positions (anterior, posterior and lateral).

Front 21

Membranous Labyrinth - contained within the bony labyrinth; it includes the following nerves:

Back 21

CN VIII Vestibular
Cochlear Component;
- vestibulochochlear n (CN VIII).

Front 22

Describe the Cochlear duct and its innervation

Back 22

- a spiral blind-ended tube containing the spiral organ (organ of Corti(organ of hearing)) with sensory hair cells - innervated by CN VIII.
- Nerve cell bodies of sensory neurons are located in the spiral ganglion.

Front 23

Describe the Utricle and it's innervation?

Back 23

- contains sensory hair cells (located in the macula utriculi), innervated by CN VIII.
- Cell bodies of sensory neurons are located in the vestibular ganglion.
- The utricle detects linear acceleration.
- hair cells implant into otolithic membrane

Front 24

hair cells of the utricle extend into the __________ and detect?

Back 24

1) otolithic membrane and detect linear acceleration.
2) innervated by CN VIII

Front 25

Describe the Saccule and it's innervation?

Back 25

- contains sensory nerve cells (located in the macula sacculi), innervated by CN VIII.
- Cell bodies of sensory neurons are in the vestibular ganglion.
- The saccule detects position of head in space plus linear acceleration and deceleration.

Front 26

Which membranous structures have their cell bodies in the vestibular ganglion and which in the spiral ganglion?

Back 26

1) Semicircular ducts, Saccule and Utricle
2) Choclear duct

Front 27

Semicircular Ducts –

Back 27

- contain sensory hair cells in three areas called the cristae ampullaris (enlarged area a the base of each semicircular canals)
- innervated by CN VIII.
- Cell bodies of sensory neurons are located in the vestibular ganglion.
- Hair cells detect rotation of the head.

Front 28

cristae ampullaris

Back 28

- (enlarged area a the base of each semicircular canals)
- contain sensory hair cells

Front 29

The membranous labryth is innervated by which CN?

Back 29

CN VIII.