Page 100 - Edited - Webster HEAD AND NECK - part 2-Merge PDF

HN 294
THE POSITION OF THE DIVISIONS
OF THE EAR IN THE SKULL
(A) SCHEMATIC DISPOSITIONS
GREATER WING INTERIOR OF BASE OF CRANIUM
OF SPHENOID Anterior FOR CONTEXT, SEE
clinoid
process.

MIDDLE Posterior clinoid process.
TYMPANIC
MEMBRANE
FOSSA FORAMEN LACERUM.

AUDITORY TUBE

Middle ear - TYMPANIC CAVITY

COCHLEAR PART of INNER EAR (hearing)

INTERNAL AUDITORY (ACOUSTIC) MEATUS (i.e. "tube")

CRANIAL NERVE VIII - VESTIBULO-COCHLEAR N

JUGULAR FORAMEN.

VESTIBULAR PART OF INNER EAR (balance & position in space).

(B) RELATIONS & ASSOCIATED CAVITIES OF THE TYMPANIC CAVITY
BONY AUDITORITURE
(in petrous temporal)
RIDGE OF PETROUS CARTILAGINOUS
TEMPORAL BONE AUDITORY TUBE
GREATER WING (below cranial base)
OF SPHENOID Thus:

RELATIONS OF MIDDLE EAR: INTERNAL
ASSOCIATED CAVITIES SQUAMOUS CAROTID ARTERY
TEMPORAL (SHEET 91)
The middle ear lies immediately behind and
above the carotid canal and above the CAROTID CANAL
beginning of the internal jugular vein (the
superior jugular bulb). The cavity extends
forwards to the nasopharynx (through the SUPERIOR JUGULAR
auditory tube) and backwards as the tympanic BULB (beginning of
internal jugular vein) IN
additus and antrum JUGULAR FORAMEN.

The epithelium of the middle ear is ciliated
columnar or cuboidal. Goblet cells are present TYMPANIC CAVITY
at the origin of the auditory tube: gaseous (open circles ؞)
exchange occurs slowly and the tube exists to
correct pressure differences between the SIGMOID VENOUS
atmosphere and tympanic cavity. The tube ADDITUS SINUS ( )

opens during swallowing (salpingopharyngeus
and tensor palati) but may be forced open by MASTOID ANTRUM

the Valsalva manoeuvre. The additus, antrum
and mastoid air cells are lined with a simple THE MIDDLE EAR CAVITY
flattened epithelium. Mucous glands are EXCLUDES THE ADDITUS ANTRUM,
present ONLY in the cartilaginous auditory & THE AUDITORY TUBE. IT IS
tube, especially near the pharynx. DIVIDED INTO THE TYMPANIC
CAVITY BELOW & EPITYMPANIC
RECESS ABOVE ( ).

kewteach\ear/nodes