Ear!

Question 1

What are the three parts of the ear?

Answer 1

External Ear, Middle Ear (within the Temporal bone), and Inner Ear (within the Temporal Bone)

Question 2

What are the two components of the external ear as discussed in class?

Answer 2

Auricle and the External Acoustic Meatus

Question 3

What is the auricle made up of?

Answer 3

Elastic Cartilage, covered with skin

Question 4

Name the components of the auricle and describe each (6).

Answer 4

Helix - outer rim of the ear
Antihelix - Inner rim (Y shaped)
Tragus -prominence on inner side of external ear
Antitragus - prominence above the lobule
Cavus - entrance to the "cave"
Lobule - Ear lobe!

Question 5

How is the lobule different than the other components of the auricle?

Answer 5

It does NOT contain any cartilage.

It is the only part of the ear that continues to grow!

Question 6

How long is the External Acoustic Meatus and what shape is it?

Answer 6

2-3cm, S-shape (therefore, to examine this structure, you must pull on the auricle to straighten out the canal)

Question 7

What is the External Acoustic Meatus made up of?

Answer 7

Outer 1/3 - Elastic Cartilage

Inner 2/3 - Bony

Question 8

What glands are in the external acoustic meatus, where are they located, and what does it secrete?

Answer 8

Ceruminous gland - secretes cerumen (ear wax) to prevent desiccation.

These glands are found in the outer 1/3 of the external acoustic meatus.

Question 9

What is the external acoustic meatus sealed by?

Answer 9

The tympanic membrane (1cm diameter)

Question 10

What are the parts of the tympanic membrane discussed in class?

Answer 10

Pars Tensa - fibrous (rigid)
Pars Flaccida - Air vibrations make it vibrate
Umbo - divet for tip of handle of malleus

Question 11

What are the three components of the middle ear?

Answer 11

Tympanic Cavity, Auditory Ossicles, and the Pharyngotympanic tube (Eustachian tube)

Question 12

What are the two components of the tympanic cavity?

Answer 12

Tympanic Cavity Proper - tube/cavity

Epitympanic Recess - aka the attic of the cavity - ossicles

Question 13

The auditory ossicles stretch from what to what?

Answer 13

Tympanic Membrane to the Oval Window (membrane against fluid)

Question 14

What kind of relationship does vibratory force and amplitude have?

Answer 14

Inverse.

When the vibratory force increases, the vibratory amplitude decreases.

Question 15

What are the three auditory ossicles?

Answer 15

Malleus (hammer)
Incus (anvil)
Stapes (stirrup)

Question 16

Name and describe the anatomy of the malleus (2).

Answer 16

Handle tip - draws in the tympanic membrane, creating the umbo (invagination)

Head - articulates with the incus

Question 17

Name and describe the anatomy of the incus (3).

Answer 17

Body - articulate with the malleus
Short limb - attaches to the chamber wall
Long limb - articulates with stapes

Question 18

Name and describe the anatomy of the stapes (3).

Answer 18

Head - Articulates with incus
Neck - Stapedius muscle location
Base (foot plate) - Presses against oval window

Question 19

Name the muscles associated with the ossicles (as discussed in class).

Answer 19

Tensor Tympani

Stapedius Muscle

Question 20

Details on the tensor tympani muscle, please!

Answer 20

Grabs the handle of the malleus

Dampens malleus-tympanic membrane

Question 21

Details on the stapedius muscle, please!

Answer 21

Inserts into the neck of the stapes.

Reduces vibrations by pulling/tension

Pulls to stabilize position also

Question 22

What happens with loss of function of a muscle associated with the ossicles?

Answer 22

Sensitivity - loud hearing

Question 23

What is the purpose of the Eustachian tube?

Answer 23

Equalizes air pressure

Drains mucus from the tympanic chamber

Question 24

What is the location of the Pharyngotympanic tube?

Answer 24

Stretches from the tympanic cavity to the nasopharynx

Question 25

What is the E-tube made up of?

Answer 25

``` Proximal side(1/3) - bony Distal side (2/3) - cartilagenous, bound by muscles ```

Question 26

Is the Eustachian tube usually open or closed?

Answer 26

Closed

Question 27

When does the Eustachian tube open?

Answer 27

When swallowing

Question 28

What is a Pastulous E-tube?

Answer 28

The Pharyngotympanic tube is always open.. an individual with this generally talks quiter because they hear themselves talking loudly since the tube is open

Question 29

What is the anatomy of the inner ear?

Answer 29

Contains the Vestibulocochlear organ, the otic capsule, the bony labyrinth, and the membranous labyrinth.

Question 30

What is the fluid called in the bony labyrinth of the inner ear?

Answer 30

Perilymph (which is cerebrospinal fluid)

Question 31

Where is the membranous labyrinth located?

Answer 31

Within the bony labryinth of the inner ear.

Question 32

What is the fluid of the membranous labyrith called and what is it high in?

Answer 32

The fluid is called endolymph and it is high in potassium.

Question 33

What is the anatomy of the membranous labyrinth (3) and the function of each part?

Answer 33

Cochlear - auditory Vestibule - static equilibrium (propioception) and the detection of acceleration Semicircular Canals - Dynamic equilibrium (detects movement)