Ear-middle Ear Flashcards
Middle ear also known as
Tympanum
What are the three parts of middle ear
Mesotympanum
Epitympanum
Hypotympanum
What are the three parts of the Tympanum bounded bye
Mesotympanum is covered by tympanic membrane
Epitympanum Is covered by bone called scutum
Hypotympanum Is covered by bone
Depth of the three layers of Middle ear
Epitympanum - 6 mm
Mesotympanum- 2 mm
Hypotympanum- 4 mm
What is protymoanum
Portion of middle ear around tympanic orifice of eustachian tube
Sensory supply of middle ear by
Jacobson’s nerve
Tympanic branch of cranial nerve nine
Jacobsons nerve referred otalgia in
- tonsillectomy
- tonsillitis
- styalgia
- cancer of the base of tongue
Epitympanum aka
Attic
Parts of malleus
Head Lateral process Neck Handle Umbo
Parts of incus
Body
Short process
Long process
Lenticular process
Stapes. Parts
Head
Footplate
What are the joints in the middle ear
Between malleus and incus – saddle joint
Between incus and stapes– ball and socket joint
What is lever ratio
M/E =1.3:1
Aerial ratio what is it
TM/Footplate = 14:1
What is middle ear transformer ratio
18:1
What is the main function of middle ear
Impedance matching mechanism
Tensor tympani muscle supplied by
Mandibular division of trigeminal nerve
Stapedius muscle is supplied by
Facial nerve
Boundaries of middle ear
Please check your book it’s very important
What are the two bony spicules present in the medial wall of the middle ear
- Ponticulus - from promontory to pyramid
2. subiculum- separates oval window from round window
Sinus tympani
Between ponticulus and subiculum
Most common residual cholesteatoma after mastoid surgery site
Sinus tympani
What is processus cochlearformis
Second genu landmark- Lateral SCC Bulge
What is middle ear cleft
It is a collection of all hollow spaces in temporal bone
What is antrum
The most constant and largest mastoid air cells
What is aditus
Connection between and antrum and middle ear
What are the five parts in middle ear cleft
ET Middle ear Aditus Antrum Rest of air cells
What is ASOM
Acute superlative otitis media
Infection of middle ear mucosa by pyogenic organisms (streptococcus pneumonia)
Stages of ASOM
Stage of tubal occlusion Stage of pre-suppuration Stage of suppuration Stage of resolution Stage of complication
Characteristic examination finding in ASOM
Cartwheel sign – read TM with dilated capillaries
Medications given in ASOM
Antibiotics
Decongestant
Analgesics
Surgical treatment in ASOM
Myringotomy
Some characteristics of safe CSOM = Tubotympanic=mucosal
Central perforation that is Margins of Tympanic membrane must be all around the perforation
In Pars tensa of Tympanic membrane
Ear discharge is mucopurulent
CHL
Most common ossicle to be eroded in ASOM is
Incus
As it has no muscle therefore least blood supply
What is the surgery for safe CSOM
Myringoplasty
What graft is used for myringoplasty
Temporalis fascia
Why is temporalis fascia used as a graft for myringoplasty
Taken from the same incision
There is no problem at donor site
It has same BMR as tympanic membrane
How should the incision be in children for myringoplasty
In younger children less than two years the mastoid tip is absent
Hence incision should be oblique
Name of the incision made in myringoplasty
Wilde post aural incision
What is underlay technique
The graft is placed below the margins of Tympanic membrane after lifting the tympanomeatal flap
What is tympanoplasty
It is the inspection and repair of a secular system in addition to myringoplasty
Wullstein classification of tympanoplasty
5 types pls read I beg
Austin classification of ossify law erosion
Four types please read
Please
Grade 3 in wullstein classification is also known as
Myringostapediopexy or
Columella tympanoplasty
Tympanic membrane graft is placed in contact with stapes
Name an other graft material used for Myringoplasty
Tragal perichondrium
Where is the Wilde postaural incision given
1 cm behind retro auricula groove from upper part of pinna to mastoid tip
How is the graft placed over the windows. And why
It is placed in such a way that is able to cover the round window and leaves the oval window open
This is done to maintain the phase difference between two windows
Also called round window shielding
What is ORP and types
Ossicular replacement prosthesis
2 types - partial and total
