Exam 2: The Ear

Question 1

The ear

Answer 1

Divided into 3 regions:
External ear
Middle ear
Inner ear

Question 2

Auricle (pinna)

Answer 2

Surrounds entrance to external acoustic canal

Protects opening of canal

Provides directional sensitivity

Question 3

External acoustic canal

Answer 3

Ends at tympanic membrane (eardrum)

Question 4

Tympanic membrane

Answer 4

Is a thin, semitransparent sheet

Separates external ear from middle early ratchet site for first auditory ossicle: malleus

Question 5

The middle ear

Answer 5

Encloses & protects: 3 auditory ossicles

Communicates with nasopharynx via auditory tube

Auditory tube permits equalization of air pressures with tympanic membrane

Question 6

Auditor ossicles

Answer 6

1. Malleus (hammer)
2. Incus (anvil)
3. Stapes (stirrup)

Question 7

Vibration of tympanic membrane

Answer 7

Converts arriving sound waves into mechanical mvmnts

Auditory ossicles conduct vibrations to inner ear

Question 8

The inner ear

Answer 8

Contains fluid: endolymph

Bony labyrinth surrounds & protects membranous labyrinth

Subdivided into:
Semicircular canals
Vestibule
Cochlea

Question 9

Vestibule

Answer 9

Encloses saccule & utricle

Receptors provide sensations of gravity & linear acceleration

Question 10

Semicircular canals

Answer 10

Contain semicircular ducts

Receptors stimulated by rotation of head

Question 11

Cochlea

Answer 11

Contains cochlear duct (elongated portion or membranous labyrinth)

Receptors provide sense of hearing

3 ducts:
Vestibular, cochlear, & tympanic duct

Question 12

Basilar membrane

Answer 12

Separates cochlear duct from tympanic duct

Question 13

Tectorial membrane

Answer 13

Attaches to inner wall of cochlear duct

Question 14

Hair cells (cilia)

Answer 14

In contact with overlying tectorial membrane

Question 15

Oval window

Answer 15

Made up of collagen fibers

Connected to base of stapes

Question 16

Round window

Answer 16

Thin, membranous partition

Separates perilymph from air spaces of middle ear