Exam 3: Head Handout Part 5
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Exam 3: Head Handout Part 5
review of head handout for exam 3
Each paranasal sinus is continuous with what?
Each paranasal sinus is continuous with the nasal cavity through what?
an aperture that opens into a meatus of nasal cavity
Infection can spread from the nasal cavities to the paranasal sinus producing what?
inflammation and swelling of mucosa of sinuses and local pain
When several sinuses are inflamed, swelling of the mucosa result in what?
blockage of one or more openings of the sinuses into the nasal cavities
The superior alveolar nerves are branches of what?
maxillary nerve (CN V2)
What do the superior alveolar nerves supply?
both the maxillary teeth and the mucous membrane of the maxillary sinus
Inflammation of the mucosa of the sinus is frequently accompanied by what?
sensation of toothache (esp. when bone is very thin in inferior part of wall of this sinus)
Why are patients w/ fractures of the frontal, ethmoid, maxillary, or nasal bones warned not to blow their noses?
because of possibility of expelling air from paranasal sinuses or nasal cavities into the subcutaneous tissues, cranium, or orbit
Where is the external acoustic meatus directed?
somewhat anteriorly as well as medially
Where do foreign bodies inserted in the meatus by infants and children usually become lodged?
in the isthmus in the bony part, where its cartilaginous and bony parts meet
With a hard blow on the chin what might happen concerning the condylar process of the mandible and the external acoustic meatus?
may drive head of mandible into meatus and injure or fracture it
Perforation of the tympanic membrane is one of several causes of:
middle ear deafness
How might perforation of the tympanic membrane occur?
Severe bleeding or escape of CSF through a ruptured tympanic membrane and the external acoustic meatus may result from what?
severe blow on the head
Severe bleeding/escape of CSF through ruptured tympanic membrane/external acoustic meatus is indicative of a skull fracture and results from:
the close relation of the tympanic cavity, mastoid antrum, mastoid cells, and the bony external acoustic meatus to the meninges of the brain
Sometimes a sull fracture passes through the bony part of the external acousti meatus and causes what?
bleeding or loss of CSF through external acoustic meatus, een with an intact tympanic membrane
How would a doctor allow pus to escape from the middle ear?
incise the tympanic membrane
Which half of the tympanic membrane is more vascular than the other?
Where are incisions made in the tympanic membrane?
Why are incisions of the tympanic membrane made posteroinferiorly?
avoids chorda tympani N and auditory ossicles
new formation of spongy bone around stapes and fenestra vestibuli
progressively increasing deafness
The bony overygrowth with otosclerosis may stop movement of what?
base of stapes or membrane of fenestra cochlea
How can hearing be restored with otosclerosis?
stapes and membrane of fenestra must be freed
Where might inflammatory conditions in the tympanic cavity/middle ear spread through?
thin tegmen tympani
What happens if inflammatory conditions in the tympanic cavity/middle ear spread through the thin tegmen tympani
causes inflammation of meninges and brain
In infants and children, what may allow direct spread of infection from the tympanic cavity to the meninges of the brain?
unossified petrosquamous fissure
What may allow infection to spread from tympanic cavity to dural venous sinuses?
veins passing through the petrosquamous suture to the superio petrosal sinus
Where are the causes of earache?
some in the ear and other at a distance
inflammation of external acoustic meatus
Why does movement of the tragus result in increased pain?
because cartilage in it is continuous with that in the external acoustic meatus
Earache may be referred pain from what?
distant lesions (the mouth through mandibular N or pharynx/larynx through vagus N)
Why might patients refer to temporomandibular joint disease as ear pain or an earache?
because of proximity of this articulation to the tragus of the ear
Are mastoid processes or mastoid cells present at birth?
As the mastoid processes develop, mastoid cells invade them from where?
By two years of age, what have the mastoid cells done?
bulged the temporal bones laterally and inferiorly, forming small mastoid processes
Infections of mastoid antrum and mastoid cells result from infection in the:
Infections may spread superiorly toward the middle cranial fossa through what in young children?
Infections cause osteomyelitis of what?
What is osteomyelitis?
Why is mastoiditis uncommon now?
advent of antibiotics
During operatios for mastoiditis, surgeons have to be conscious of which nerve?
What is one access to the tympanic cavity?
through the mastoid antrum
Hydrops of internal ear (Meniere's disease [syndrome])
abnormal increase in amount of endolymph
What does the excess fluid in the ear produce?
accompanied in later stages by tinnitus or noises in the ear and deafness
What are the pathological changes resulting from dilation of the endolymphatic system?
degeneration of hair cells in maculae of the vestibule and in the spiral organ