Temporal Bone - inner ear/vestibular pathway

Question 1

the pterion is where which four bones meet?

Answer 1

temporal, parietal, frontal, and sphenoid bones

Question 2

what foramen does the middle meningeal artery pass through?

Answer 2

foramen spinosum

Question 3

the vestibule, cochlea etc sit in what part of the temporal bone?

Answer 3

in the petrous part of the temporal bone

Question 4

the facial nerve comes from which brachial arch?

Answer 4

2

Question 5

the facial nerve supplies motor innervation to what muscles?

Answer 5

stapedius, stylohyoid, posterior belly digastric and muscles of facial expression

Question 6

what nucleus is associated with the facial nerve?

Answer 6

superior salivatory nucleus

Question 7

what two ganglia are associated with the facial nerve?

Answer 7

pterygopalatine ganglion and the submandibular ganglion

Question 8

What is the sensory nucleus associated with the facial nerve?

Answer 8

nucleus solitarius

Question 9

the facial nerve exits the brain where?

Answer 9

the cerebellopontine angle

Question 10

does the maxillary artery or nerve come through the infratemporal fossa?

Answer 10

the maxillary artery goes through the infratemporal fossa b/c the maxillary nerve goes through the foramen rotundum which is the back door to the pterygopalatine fossa

Question 11

ordinary somatic sensation from the head and neck goes to which nucleus?

Answer 11

the trigeminal nucleus

Question 12

describe the pathway of the parasympathetics associated with the occulomotor nerve

Answer 12

• start at edinger westphal nucleus
• pass through superior orbital fissure
• synapse at the cilliary ganglia
• travel with opthalmic nerve to the cilliary apparatus

Question 13

describe the path of the parasympathetics associated with the facial nerve

Answer 13

(greater petrosal)

• starts at superior salivatory nucleus
• passes through internal acoustic meatus
• meets up with the deep petrosal nerve
• enters pterygoid canal
• synapses at the phenopalatine ganglion
• travels with the maxillary nerve to lacrimal gland

(chorda Tympani)

• starts in superior salivatory nucleus
• exits through internal acoustic meatus
• passes through petrotympanic fissure
• synapses in the submandibular ganglia
• travels with lingual branch of mandibular nerve to sublingual glands
  *

Question 14

describe the pathway of the parasympathetics associated with the glossopharyngeal nerve

Answer 14

• start at inferior salivatory nucleus
• passes through foramen ovale
• synapses with otic ganglion
• travels with auriculotemporal branch of mandibular to parotid gland

Question 15

what nerves pass through the internal acoustic meatu?

Answer 15

7 and 8 arise at the cerebellopontine angle, then enter the internal acoustic meatus together

Question 16

describe the structure of the cochlea

Answer 16

bony labyrinth on outside

membranous labyrinth on inside

between bony labyrinth and membranous labyrinthe= perilymph

membranous labyrinth is filled with endolymph

Question 17

what are the small particles in your endolymph called which move hair cells in the inner ear?

Answer 17

otoliths = rocks

Question 18

coming from the inner ear, where do the first order neurons synapse?

Answer 18

at the pontomedullary junction of the brainstem

Question 19

where do the second order neurons from our vestibule nerve go?

Answer 19

cerebellum and nerves of vestibulospinal tract - don’t need to think about it, just automatically do it!

It also goes to the thalamus and cortex for conscious awareness

Question 20

what is the medial longitudinal fasciculus?

Answer 20

connects the brainstem nuclei - especially 3,4, and 6 going to the eye - it allows for coordination of movement?

Question 21

describe the process of hearing?

Answer 21

• sound hit tympanic membrane - amplified x2
• sound vibrates the malleus, incus and stapedius - amplified x9
• vibration transmited at the oval window
• wave transmitted along scala vestibuli and back along scala tympani in the perilymph
• the wave in the scala media acts on the hair cells within - transmitting sound

Question 22

where does the auditory cortex sit?

Answer 22

below the lateral sulcus

Question 23

where does auditory sensory information go to?

Answer 23

goes to the ventral and dorsal cochlear nuclei, then it crosses over as trapezoid body and ascends as lateral lemniscus

• relays in the medial geniculate body and then to the auditory cortex below lateral sulcu

*some fibers relay to the inferior colliculus = somatic reflexes to sound

Question 24

what is the difference bewteen conductive deafness and sensorineural deafness?

Answer 24

conductive deafness= defective transmission of wave sounds from the external acoustic meatus or the tympanic membrane

sensorineural deafness is a disease of the inner ear or the nerves associated

Question 25

what causes hyperacusis?

Answer 25

paralyzing of the stapedius muscle - cannot dampen noise

Question 26

What is Menieres disease?

Answer 26

disorder of the inner ear = deafness, vertigo, tinnitus ( ringing noise)