LECTURE: Ear Flashcards
(96 cards)
1
Q
The ear is divided into
A
- external ear
- middle ear
- internal ear
2
Q
Part of the ear that is projecting from the side of the head but also the canal leading inward
A
external ear
3
Q
Part of the ear that opens into the pharynx through a narrow tube
A
middle ear
4
Q
The middle ear is separated from the external ear by what?
A
the tympanic membrane
5
Q
Part of the ear that has to do with hearing and balance
A
internal ear
6
Q
A
7
Q
Comprised of elastic cartilage and skin, it collects sound waves and funnels them to the external auditor meatus
A
auricle
8
Q
A
9
Q
The blood supply of the lateral auricle is from
A
twigs (auricular branches)
10
Q
Twigs (auricular branches) are from what artery?
A
superficial temporal artery
11
Q
The medial auricle is supplied by which artery?
A
the auricular branch of the posterior auricular artery
12
Q
The auricular branch of the posterior auricular artery is a branch of which artery?
A
the external carotid
13
Q
The nerves supplying the auricle is from which nerve? (3)
A
- the auriculotemporal nerve (from V3)
- the great auricular nerve (from cervical plexus)
- the lesser occipital nerve (from cervical plexus)
14
Q
A fibrous membrane with a thin layer of skin its lateral side and mucosa on its medial side
A
tympanic membrane
15
Q
It slopes from superior-lateral to inferior-medial, with a concavity toward the meatus.
A
tympanic membrane
16
Q
A central depression in the concavity of the tympanic membrane is called the
A
umbo
17
Q
The umbo is formed by the attachment of the end of the handle of one of the auditory ossicles called the…
A
malleus
18
Q
Vibrations of the tympanic membrane are relayed to the
A
ossicles
19
Q
General sensation from the external auditory meatus and the external surface of the tympanic membrane is carried mainly by which nerve?
A
the auriculotemporal branch of V3
20
Q
Which nerves carry sensation from the external surface of the tympanic membrane and inferior aspect of the external meatus?
A
CN VII (facial) and X (vagus)
21
Q
The internal surface of the tympanic membrane is innervated by which nerve?
A
CN IX (glossopharyngeal)
22
Q
Contents of the middle ear
A
- auditory ossicles
- stapedius and tensor tympani muscles
- chorda tympani and tympanic nerves
23
Q
Components of the auditory ossicles
A
malleus, stapes, incus
24
Q
Walls of the middle ear (tympanic) cavity is formed by the
A
petrous portion of the temporal bone
25
Shaped somewhat like a box, with convex medial and lateral walls
Walls of the middle ear (tympanic) cavity
26
Lateral convexity of the wall of middle ear cavity is formed from what?
promontory
(the tympanic membrane and the medial convexity)
27
The roof of the middle ear is called the
tegmental wall
28
The roof of the middle ear is somewhat elevated, allowing additional space called the
epitympanic recess
29
The posterior, or mastoid, wall of the middle ear has an opening called the
aditus
30
The aditus leads to what space?
the mastoid antrum
31
What communicates with mastoid air cells in the middle ear?
the mastoid antrum
32
The floor of the middle ear is called the
jugular wall
(because the bulb of the internal jugular vein is below)
33
The ______ span the lateral and medial walls of the middle ear.
ossicles
34
The medial wall also has two apertures, or windows called
1. the oval (vestibular) window
2. the round (cochlear) window
35
The oval window is covered by the _____ and the round window is covered by a \_\_\_\_.
The oval window is covered by the **_stapes**_ and the round window is covered by a _**membrane_**.
36
The ___________ enters the temporal bone through the internal auditory meatus and travels in the wall of the tympanic cavity.
facial nerve (CN VII)
37
The chorda tympani nerve, a branch of \_\_\_\_\_\_\_\_\_, courses through the middle ear cavity, between malleus and incus.
facial nerve
38
A branch of the glossopharyngeal nerve (CN IX), the tympanic nerve, forms a plexus in the tympanic cavity called the
tympanic plexus
39
The tympanic plexus carries sensory information from the tympanic cavity and part of it travels through the cavity as the
lesser petrosal nerve
40
The anterior wall of the tympanic cavity is called the
carotid wall
(because of the proximity of the carotid artery)
41
There are two openings in the anterior wall of the tympanic cavity - what are they?
1. 1 occupied by the tensor tympani muscle
2. opening for the pharngotympanic tube
42
The pharyngotympanic tube is also called the
eustachian tube or auditory tube
43
What is the function of the pharyngotympanic tube?
allows communication between the middle ear (tympanic) cavity and the nasopharynx
44
A slender ribbon of muscle whose **origin** is the petrous portion of the temporal bone and the pharyngotympanic tube and **insertion** is the handle of the malleus.
tensor tympani
45
Which muscle(s) contracts in response to loud sounds to protect the ear from damage?
tensor tympani and stapedius
46
Innervation of the tensor tympani
the mandibular division of the trigeminal nerve (V3)
47
A very small projection of bone called the pyramid provides for the attachment of \_\_\_\_\_\_\_\_.
stapedius
48
This muscle runs from the pyramid to the stapes and tenses in response to loud sounds to protect the ear from damage.
stapedius
49
Innervation of stapedius
facial nerve (CN VII)
50
Components of the auditory ossicles
malleus,
51
Which part of the ear contains the vestibulocochlear organ?
inner ear
52
The vestibulocochlear organ's function
the reception of sound and the maintenance of balance
53
The inner ear consists of a bony labyrinth
otic capsule
54
The bony labyrinth can be subdivided into
* vestibule
* semicircular canals
* cochlea
55
What makes up the vestibular complex?
vestibule + semicircular canals
56
Inside the bony vestibule are two membranous dilations called the
utricle and the saccule
57
The utricle and the saccule are connected by
a slender passageway continuous with the endolymphatic duct
58
The endolymphatic duct emerges through the bone of the
posterior cranial fossa
59
What is the storage reservoir for endolymph?
endolymphatic sac
60
The utricle and saccule each have a specialized area of sensory epithelium called
macula
61
What contain hair cells with their processes embedded in a gelatinous layer which is covered by a densely packed layer of (calcium carbonate) crystals?
maculae
62
The calcium carbonate crystals are called
otoconia or otoliths
63
How does the ear let the brain know the position of the head?
changing the position of the head causes a shift in the position of the otoconia, which stimulates the hair cells, and the information is carried by the **vestibulocochlear nerve**
64
Inside the bony semicircular canals are the 3 semicircular ducts called:
1. anterior
2. posterior
3. lateral
65
The semicircular ducts are set at what angles to each other?
right angles
66
At one end of each semicircular duct is a dilation called an \_\_\_\_\_\_\_, which contains a sensory area called **crista ampullaris**.
ampulla
67
Each crista ampullaris contains hair cells (much like those located in the maculae) which have projections (cilia) embedded in a gelatinous structure called a \_\_\_\_.
cupula
68
What happens when the head rotates in the plane of the canal?
movement of the endolymph along the canal axis pushes the cupula and distorts the receptor processes
69
Fluid movement in one direction _______ them and in the other direction _______ them
Fluid movement in one direction **_stimulates**_ them and in the other direction _**inhibits_** them.
70
A “nod” moves perilymph in the
anterior canal
71
Shaking the head “no” moves the perilymph into the
lateral canal
72
Tilting the head to the side moves perilymph in the
posterior canal
73
Information of movement in the semicircular canals and ducts travels through which nerve?
vestibulocochlear nerve
74
Which part of the ear is concerned with hearing?
cochlea
75
The cochlea makes ____ turns around a bony core
2 ½
76
The bony core which the cochlea wraps around is called the
modiolus
77
The axis of the modiolus is perpendicular to the long axis of the
petrous portion of the temporal bone
78
If you cut a cross-section through a turn of the cochlea you would notice that the _______ helps separate it into three regions.
membranous labyrinth
79
What are the 3 regions that the membranous labyrinth divides the cochlea into?
1. cochlear duct (scala media)
2. vestibular duct (scala vestibule)
3. tympanic duct (scala tympani)
80
Cochlear duct
scala media
81
vestibular duct
scala vestibule
82
tympanic duct
scala tympani
83
The cochlear duct is filled with what fluid
endolymph
84
What fluid between the membranous labyrinth and bony labyrinth?
perilymph
85
The membrane between the cochlear duct and the tympanic duct is called the
basilar membrane
86
This organ sits on the basilar membrane
the spiral organ of Corti
87
Consists of rows of hair cells
The organ of Corti
88
The hair cells which have their cilia in contact with
the tectorial membrane
89
When the basilar membrane oscillates in response to waves in the fluid, the hair cells
move with it
90
Since the cilia of the hairs cells are in contact with a tectorial membrane (which is not moving), they become…
distorted and relay information to the brain through the cochlear portion of the vestibulocochlear nerve (sound conduction)
91
The cell bodies of the primary afferent neurons of the spiral organ are found where?
the spiral ganglion within the modiolus
92
The bony labyrinth is supplied by the same blood vessels that supply the …
adjacent parts of the temporal bone
93
The membranous labyrinth is supplied by the
labyrinthine artery
94
The labyrinthine artery comes from
m the anterior inferior cerebellar artery **_or_** directly from the basilar
95
The labyrinthine artery travels through the internal auditory meatus with which nerves?
CN VII and VIII
96
A Summary of the Conduction of Sound
1. sound waves collected by the **auricle** are passed into the **external auditory meatus**
2. vibrations of the **tympanic membrane** are relayed to the **ossicles**
3. vibrations of **stapes** are transferred to the perilymph through the **oval** (vestibular) window
4. vibrations of the perilymph are transmitted to the **basilar membrane**
5. vibrations of the basilar membrane result in displacement of **hair cell cilia**
6. neurons from hair cells respond to movement by **depolarizing**
