Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anatomy > 11 - NS Ear and Audition > Flashcards

11 - NS Ear and Audition Flashcards

1
Q

What are the sensory nerves involved in hearing

A

CN VIII (vestibulocochlear): hearing and balance
CN X (vagus): sensory to auditory canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the motor nerves involved in hearing

A

CN V (trigeminal): tensor tympani muscle of middle ear

CN VII (facial): stapedius muscle of middle ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

From where are the components of the ear carved from

A

the petrous portion of the temporal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the three principle regions of the ear

A

external, middle, inner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

External Ear - glands

A

ceruminous glands secrete wax that traps foreign bodies and repels insects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe how the skin of the external auditory canal is attached

A

2/3 = cartilage (contains fat)
1/3 = bone
- firmly attached to the periosteum of the bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the parts of the middle ear

A

ossicles (in middle ear interior)
tympanic membrane cone (eardrum)
connective tissue covered by skin externally, mucosa internally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the function of the ossicles

A

mechanically relay vibrations from the tympanic membrane to the oval window of the inner ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

where are the ossicles found

A

suspended by ligaments and connected by synovial joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the parts of the ossicles

A

malleus (hammer)
incus (anvil)
stapes (saddle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

which muscles help to dampen sounds

A

tensor tympani (dampens ossicle movement when chewing - CN V)

stapedius (dampens ossicle movement during loud sounds - CN VII)

muscles tense (constrict) so tympanic membrane can’t vibrate as much

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What ensures that the tympanic membrane vibrates effectively

A

pressure equilibration

Tympanic membrane should be able to move back and forth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What would happen if there was high pressure in the middle ear

A

tympanic membrane would be bulging out
can’t vibrate as effectively as sounds come in
deaf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What tubes in the middle ear connect to the great outdoors

A

external auditory canal
auditory tube (from pharanx)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Auditory tube

A

runs through pharanx
surrounded by skeletal muscle
changes shape when you swallow
- swallowing allows pressure to be equilibrated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the mastoid process

A

bored out bone at the back of the ear
sponge-like covered by mucous membrane

any part of skull that is not needing absolute strength is hollowed out and put air spaces in
air spaces communicate to great outdoors so head doesn’t explode on the plane
makes skull lighter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do middle ear infections occur

A

respiratory tract infections ascend that auditory tube to the middle ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What could happen as a result of infections in the middle ear

A
  1. rupture of tympanic membrane and drainage of fluid through external ear (collagen build up)
  2. infection spread into mastoid air cells leading to mastoiditis (increase pressure in bone)
  3. erosion of temporal bone above middle ear leading to meningitis
19
Q

What is the inner ear made of

A

series of channels carved out of the temporal bone
- cochlea
- semicircular canals

20
Q

How is hearing transmitted to the inner ear

A

stapes acts on the oval (vestibular) window to transmit vibrations to the organ of hearing (spial organ) contained within the cochlea which resembles a snail shell

21
Q

How are sound waves transmitted

A
  1. sounds waves collected by the auricle and external auditory meatus and directed to the eardrum
  2. sound waves vibrate the tympanic membrane
  3. transmission of vibrations across middle ear by the ossicles
  4. stapes transfers vibrations to the oval (vestibular) window
  5. vibrations transferred to perilymph of scala vestibuli
  6. vibrations transfer to scala tympani and eventually cochlear (round) window
  7. pressure waves in scala vestibuli and tympani set up waves in the endolymph of the cochlear duct
  8. pressure waves in the endolymph cause the basilar membrane to vibrate, moving hair cells (receptors) of the spiral organ -> nerve impulses generated in the cochlear nerve (CN VIII)
22
Q

What does the spinal organ do

A

Converts vibrations into nerve impulses

23
Q

What does the spinal organ consist of

A

hair cells (stereo cilia)
supporting cells

24
Q

How are the first order neurons stimulated

A

stimulation of stereo cilia on hair cells causes NT release, stimulating first order neurons of the cochlear nerve (CN VIII)

25
Q

How does frequency detection work

A

The length of the basilar membrane fibres acts to tune the different parts of the cochlea to different frequencies

26
Q

Describe the auditory pathway to the brain

A
  1. auditory info travels bilaterally after entering the brainstem
  2. Cochlear nuclei (CN VIII): info decussates beyond this point - medulla oblongata
  3. Superior olivary nuclei: stereo sound (localization) - pons
  4. Lateral lemniscus: white matter tract (part of RAS)
  5. Inferior colliculus: acoustic startle reflex - dorsal midbrain
  6. Thalamus: selective attention, filters out self-generated sounds (voice, heart, chewing) - medial geniculate nucleus
  7. Primary auditory cortex: conscious perception of sound - temporal lobe
27
Q

What are the types of hearing loss

A

conduction deafness
sensory deafness

28
Q

Conduction deafness (where, what, causes)

A
  • middle and outer ear
  • reduction in sound amplitude
  • hear sound of blood rushing in carotid arteries
  • Causes: ear wax, rupture of tympanic membrane, damage to ossicles (arthritis)
29
Q

Sensory Deafness (where, what, causes)

A
  • inner ear, CN VIII
  • high tones affected (rumbling)
  • tinnitus (continuous hiss)
  • Causes: infarct, trauma, prolonged noise, drug toxicity, tumours, Meniere’s disease - high endolymph pressure)
30
Q

What are the parts of the vestibular apparatus

A

Consists of receptor organs for equilibrium
- utricle (bag)
- saccule (small sac)
- semicircular ducts (x3)

31
Q

What are the utricle and saccule

A

otolithic organs that contain an inner region called the macula

32
Q

What is the semi-circular duct

A

in a linear plane
- the anterior and posterior ducts are on the vertical plane
- the lateral duct is on the horizontal plane
- all three ducts lie at right angles to one another

33
Q

What is the maculae

A

Contains hair cells and supporting cells and is part of the utricle and saccule
- detects linear acceleration/deceleration

34
Q

What is a hair bundle

A

hair cells/sensory receptors contain a hair bundle

35
Q

What do the supporting cells do

A

surround the hair cells and produce the otolithic membrane and otoliths (calcium carbonate crystals)

36
Q

How are the utricle and saccule positioned

A

perpendicular to each other within the inner aspect of the vestibular apparatus

37
Q

What position does the utricle have when head is upright

what do the hair cells respond to

A

horizantal

linear acceleration and deceleration and when the head tilts forward or backward

38
Q

What position does the saccule have when the head is upright

what do the hair cells respond to

A

vertical

linear acceleration and deceleration in the vertical direction

39
Q

What is an ampulla

A

dilated region of the ducts that contain a crista (folds), each consisting of hair cells and supporting cells

40
Q

What is the crista

A

covered in gelatinous substance (the capula) that moves and bends the hair cells when the surrounding endolymph moves as the head rotates

41
Q

What does bending hair bundles do

A

in one direction, depolarizes hair cells
in opposite direction, hyperpolarizes

42
Q

How does vestibular information travel

A

from the cortex and is integrated in the brainstem

hair bundles –> vestibulocochlear nerve (CN VIII) –> vestibular nuclei (medula/pons) –> thalamus –> sensory cortex (verstibular area in the parietal lobe)

43
Q

How is vestibular information integrated into the brainstem

A
  1. cranial nerves for eye movement (CN III, IV, VI) - scanning motions
  2. Accessory nerve (XI) for head/neck control - sternocleidomastoid + trapezius
  3. Vestibulospinal tract for skeletal muscle control - indirect motor pathway, posture and balance
  4. Cerebellum for limb and axial positional control - dedicated pipeline to coordinate movements

Anatomy (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions