Ear Flashcards
Where does the frontal sinus drain?
via frontonasal duct into the semilunar hiatus of the middle meatus
Where does the ethmoid sinus drain
into the middle and superior meatus
Where does the sphenoidal sinus drain?
into the sphenoethmoidal recess
Where does the maxillary sinus drain?
it drains into the semilunar hiatus into the middle meatus
CN 5 V1
innervates lateral wall and anterior septum of the nose as well as parts of the sensation of the upper face
Choanae
opening at the back of the nasopharynx
muscle of the soft palate
tensor veli palatini
Muscles of the Middle Ear
- stapedius muscle
- tensor tympani muscle
![](https://s3.amazonaws.com/brainscape-prod/system/cm/369/961/890/a_image_thumb.jpeg?1628632183)
Anatomy of the Tympanic Membrane
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Describe the pathway of hearing sensation
- oval window vibrates the perilymph fluid in the inner ear which is then transferred to the endolymph fluid within the Organ of Corti within the cochlea which stimulates hair cells
- hair cells transmit sound information to the CNS via CN VIII
- CNS: CN VIII → medulla oblongata→inferior colliculus of midbrain → superior olives → thalamus → auditory cortex
![](https://s3.amazonaws.com/brainscape-prod/system/cm/369/961/893/a_image_thumb.jpeg?1628632754)
Semicircular canals
- filled with endolymph
- respond to rotation of the head in 3 planes
- hair cells at the base of the semicircular canals are distorted when the head moves in the x, y, z planes
Vestibule
- made up utricle and saccule
- hair cells within the vestibule are pressed down by gravity, or if gravity /accelearation changes → hair cells become distorted
![](https://s3.amazonaws.com/brainscape-prod/system/cm/369/961/915/a_image_thumb.jpeg?1628633211)
Vestibular pathway
- for balance and sensation of balance
- vestibular hair cells send signals via CN VIII (vestibulocochlear)
- received by pons and medulla oblongata → cerebellum and cerebral cortex
![](https://s3.amazonaws.com/brainscape-prod/system/cm/369/961/916/a_image_thumb.jpeg?1628633313)
Nystagmus
- rapid, involuntary eye movement as a result of activation of the vestibular system (usually side to side)
CN V3
mandibular brach: motor control of the tensor tympani muscle