Ear - Outer, Middle, and Inner

Question 0

What is the eustacian tube?

Answer 0

Connects the middle ear to the nasopharynx

Question 1

What is the acoustic canal?

Answer 1

Passageway from the external ear to the middle ear

Question 2

What are the ossicles?

Answer 2

In the middle ear, connect the outer ear to the inner ear

Question 3

The inner ear contains?

Answer 3

All sensory apparatus for both hearing and balance

Question 4

What is the pinna?

Answer 4

Outer ear consisting of Elastic cartilage and covered with regular thick skin. Serves to funnel sound to the eternal acoustic meatus

Question 5

What is the external acoustic meatus?

Answer 5

The tube that extends laterally from the pinna medially to the tympanic membrane (ear drum)

Question 6

Describe the external acoustic meatus

Answer 6

Lateral portion is supported by cartilage
Medial portion is surrounded and supported by temporal bone
Inner surface is lined by thin skin that even extends across the outer surface of the tympanic membrane. Contains modified sweat glands that secrete waxy cerumen

Question 7

Where is waxy cerumen secreted?

Answer 7

The external acoustic meatus

Question 8

What separates the outer ear from the middle ear?

Answer 8

The tympanic membrane

Question 9

Describe the central stroma of the tympanic membrane?

Answer 9

Flattened cone with two layers of collagen fibers, some oriented radially and some circularly.
Tough material, particularly at the pars tensa

Question 10

What is the pars tensa?

Answer 10

The connection between the middle ear bone, the malleus, to the tympanic membrane

Question 11

What is the pars flaccida?

Answer 11

The portion of the tympanic membrane that has reduced stiffness due to less collagen fibers

Question 12

Describe the covering of the tympanic membrane

Answer 12

Outer - thin skin w/o hair or glads

Inner - simple squamous epithelium of the middle ear cavity

Question 13

T or F: The tympanic membrane is extremely thin and prone to damage

Answer 13

T

Question 14

What is characteristic of the tympanic membrane in histological stain?

Answer 14

Radial and circular collagen fibers

Question 15

What is the tympanic cavity?

Answer 15

The middle ear cavity and is essentially a space or cavity within the temporal bone

Question 16

The tympanic cavity is lined by?

Answer 16

Simple squamous or simple cuboidal cells

Question 17

The tympanic cavity is connected to the inner ear via?

Answer 17

Oval and round windows.

Question 18

How does the middle ear connect to the nasopharynx?

Answer 18

Via the Eustachian tube.

Question 19

What is the Eustachian tube?

Answer 19

Provide open passageway between the nasopharynx and the middle ear cavity. Site of most childhood ear infections due to bacteria traveling up the Eustachian tubes to the middle ear

Question 20

Name the middle ear osccicles

Answer 20

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

Question 21

Function of the ossicles?

Answer 21

Smallest bones in the body and transmit vibrations from the tympanic membrane to the inner ear

Question 22

What is the malleus?

Answer 22

Attached to the tympanic membrane. The hammer

Question 23

What is the incus?

Answer 23

Attaches the malleus to the stapes (anvil)

Question 24

What is the stapes?

Answer 24

Foot is attached to the membrane overlying the oval window. The stirrup

Question 25

What is the tensor tympani?

Answer 25

Muscle that inserts onto the periosteum of the malleus and dampens vibration

Question 26

What is the stepedius?

Answer 26

Muscle that attaches to the stapes and dampens vibration

Question 27

What is the bony labyrinth?

Answer 27

The inner ear complex cavities in the dense petrous part of the temporal bone. Contains the cochlea, the vestibule, and the semicircular canals

Question 28

Where is perilymph located?

Answer 28

In the bony labyrinth of the inner ear (like regular extracellular fluid)

Question 29

What is the membraneous labyrinth?

Answer 29

Held within the bony labyrinth and is a system of sacs and ducts.
Correspond to the bony equivalents e.g. the bony cochlea has within it the membraneous cochlear duct, the bony semicircular canals have the membranous semicircular ducts and so on.

Question 30

What is found within the bony vestibule?

Answer 30

The membranous sacs known as the utricle and the saccule

Question 31

What fluid is contained in the membranous labyrith?

Answer 31

Endolymph, which is like intracellular fluid

Question 32

What lines the membranous labyrinth?

Answer 32

Continuous sheet of epithelium that is mostly simple squamous
Specialized in certain regions to form sensory receptor hair cells.

Question 33

What are the specialized epithelial areas of the membranous labyrinth?

Answer 33

Areas like the organ of Corti of the cochlear duct, the maculae of the uticle and saccule, and the christae of the semicircular ducts

Question 34

Sensory receptor cells in the membranous labyrinth is…

Answer 34

Columnar epithelial with cilia, stereocilia or both. Range in number of cilia. Only have one celium called the kinocilium. These kinocilium are embedded in a gelatinous covering surrounded by endolymph.

Question 35

Describe the function of kinocilia

Answer 35

Pressure waves from external sounds in the cochlea or motion in the semicircular canals moves endolymph which bends the kinocilia and results in depolarization