MIDDLE EAR
- Tympanic cavity or middle ear , ear air cavity
- Formed by
- petrous part of temporal bone
- between external ear and internal ear
- shape
- like a Cube , but not perfect cube
- cube is compressed from side to side
- lateral and medial walls are large
- other walls are narrow
- cavity appears biconcave in coronal section
- 6mm distance between at upper end
- 2mm in middle
- 4mm in lower part or floor
- parts
- tympanic cavity proper
- opposite the tympanic membrane
- epitympanic recess
- above the level of tympanic membrane
- Communications
- anteriorly
- nasopharynx through auditory tube
- posteriorly with
- mastoid antrum and mastoid air cells through aditus
- walls
- Tegmental wall; tegmental roof
- formed by thin plate of bone called tegmen tympani
- separates middle ear from middle cranial fossa
- prolonged forwards as roof of canal for tensor tympani
- transmits a vein from middle ear to superior petrosal sinus
- Epitympanic recess
- Cupular part
- Jugular wall; floor
- thin plate of bone which is a part of temporal bone
- separates middle ear from superior bulb of internal jugular vein
- nearer to medial wall floor
- tympanic canaliculus
- transmits tympanic branch of glossopharyngeal nerve
- to medial wall of middle ear
- Styloid prominence
- Labyrinthine wall; medial wall
- Oval window
- Fossa of oval window
- Promontory
- Groove of promontory
- Subiculum of promontory
- Sinus tympani
- Round window
- Fossa of round window
- Crest of round window
- Processus cochleariformis
- Secondary tympanic membrane
- Mastoid wall; posterior wall
- Above to downwards
- Superiorly
- Aditus to mastoid antrum
- epitympanic recess communicates with tympanic antrum
- Prominence of lateral semicircular canal
- Prominence of facial canal
- Fossa of incus
- near junction of posterior and medial walls
- Pyramidal eminence
- Posterior sinus
- Tympanic aperture of canaliculus for chorda tympani
- Mastoid antrum
- Mastoid cells
- Tympanic cells
- Carotid wall or anterior wall
- upper most part
- opening of canal for tensor tympani
- middle part
- opening of auditory tube
- inferior part
- thin plate of bone
- forms posterior wall of carotid canal
- separates middle ear from internal carotid artery
- perforated by
- superior and inferior sympathetic carticotympanic nerves
- tympanic branch of ICA
- Bony septum continues
- processus cochleariformis
- posterior end forms a pulley around tendon of tensor tympani
- Membranous wall; lateral wall
- formed by tympanic membrane and partly by squamous temporal bone
- separates middle ear from external acoustic meatus
- near tympanic notch
- AUDITORY OSSICLES
- Stapes
- Head of stapes
- Anterior limb
- Posterior limb
- Base of stapes; footplate
- Incus
- Body of incus
- Long limb
- Lenticular process
- Short limb
- Malleus
- Handle of malleus
- Head of malleus
- Neck of malleus
- Lateral process
- Anterior process
- ARTICULATIONS OF AUDITORY OSSICLES
- Incudomallear joint
- Incudostapedial joint
- Tympanostapedial syndesmosis
- Ligaments of auditory ossicles
- Anterior ligament of malleus
- Superior ligament of malleus
- Lateral ligament of malleus
- Superior ligament of incus
- Posterior ligament of incus
- Stapedial membrane
- Anular ligament of stapes
- MUSCLES OF AUDITORY OSSICLES
- Tensor tympani
- Stapedius
- Mucosa of tympanic cavity
- Posterior fold of malleus
- Anterior fold of malleus
- Fold of chorda tympani
- Recesses of tympanic membrane
- Anterior recess
- Superior recess Prussak
- Posterior recess
- Fold of incus
- Fold of stapedius
- PHARYNGOTYMPANIC TUBE; AUDITORY TUBE
- Tympanic opening
- Bony part
- Isthmus
- Tubal air cells
- Cartilaginous part
- Cartilage of tube
- Medial lamina
- Lateral lamina
- Membranous lamina
- Mucosa; mucous membrane
- Tubal glands
- Pharyngeal opening
