Temporal Bone

HESP311 Temporal Bone

Histopathology

microscopic study of the changes in tissue caused by disease

How many bones in the skull?

22; 14 in facial skeleton and 8 in the cranium

Temporal Bone

bone that forms parts of the side of the skull and floor of the cranial activity

Squamous Portion

superior to the ear canal, large fan-like appearance, protects temporal lobe

Tympanic Portion

ear canal, forms the floor and wall of EAC, small thin and curved

Mastoid Portion

posterior to the pinna, hone-vombed bone for air press regulation and ear protection

Petrous Portion

Deep in cranium, houses the inner ear, Otic Capsule (houses boney labyrinth), CNVIII Nerve

Zygomatic Process

a projection of the squamous portion that connects to cheek

Styloid process

tympanic portion, spike, inferior to EAC, anchor for muscles for speech

temporomandibular joint (TMJ)

hinge joint between temporal bone and lower jaw

Mandibular FOssa

the depression in the temporal bone into which the condyle of the mandible fits

Otis Capsule

surrounds the labyrinth

CNVIII Nerve

vestibulocohlear nerve

CT scan

uses xray/ultrasound to create a 3D view of bone, tissues and organs; slight radiation exposure

MRI

measures how much water is in different tissues; best for tissues, can show diseases that CT cannot

Longitudinal Fractures

most common; conductive and mixed hearing loss

Transverse Fractures

less common; highest risk of sensorineural, vertigo, 50% facial cases

Mastoiditis

may start with ME infection; pain, otalgia, tenderness, swelling; antiobiotics, mastoidectomy

Mastoidectomy

the surgical removal of mastoid cells (simple, modified, radical)

Perilymph

fluid contained in the labyrinth of the inner ear

Membranous Labyrinth

membrane-covered tubes inside the bony labyrinth

Tympanum

middle ear space

Nystagmus

rapid, involuntary movements of the eyes

Vestibular

pertaining to the vestibule

Otorrhea

discharge from the ear

Hemotympanum

blood observed behind the tympanic membrane

Postauricular Ecchymosis

bruising or arch-shaped brusing behind the auricle (Battle's sign)

Periorbital Ecchymosis

raccoon eyes, circular brusing

Mastoid Air Cells

air spaces in the mastoid process of the temporal bone that communicate with the middle ear cavity

Vestibular Stimulation

vestibular part of inner ear is highly sensitive to thermal stimulation

Mastoid Antrum

air space in petrous portion of the temporal bone, communicating posteriorly with mastoid cells and anteriorly with the tympanic cavity

Aditus

larger irregular aperture on the posterior wall of tympanic cavity

Acute Otitis Media

Untreated Mastoiditis

vertigo, mastoid destruction, meningitis, infection spread

Bony Labyrinth

rigid, bony outer wall of inner ear in temporal bone

Bony labyrinth consists of...

vestibule, semicircular canals, cochlea

Ossification of Cochlea

supposed to be filled with endolymph and perilymph; after infection or trauma, it may be replaced by bone

Etiology of Cochlea Ossification

inflammation from disease or trauma; bacterial meningitis most common cause

Cochlear Implant Prognosis with TB Fractures

secondary ossification of cochlea can impact prognosis of cochlear implantation

Mastoid Air Cell System is filled with a gas mixture consisting of mostly....

Nitrogen (80.5%)