Middle & Inner Ear Flashcards
Eustachian tube divided into
Bony part ~ 1.2 cm
Cartilaginous part ~ 2.4 cm
Narrowest part of Auditory tube
Isthmus
Function of Eustachian tube
To equalise the pressure on both side of Tympanic Membrane
Muscle responsible for opening of Eustachian tube
Tensor Veli Palatini Muscle
Assisted by Levator Veli Palatini Muscle
Tensor Veli Palatini is also know as
Dilator Tubae Muscle
Lateral Wall of Middle Ear ~
Derived from ~
Tympanic Membrane
Derived From 1st Pharyngeal Membrane
Made up of all the 3 germ layers
Roof of Middle Ear is Formed By ___________
And is separating Middle Ear from _______
Tegmen tympani ~ thin plate of bone
Separates Middle Ear from Middle Cranial Fossa
Floor (Bony plate) of Middle ear is separating from
Floor is pierced by
Internal Jugular Vein
Pierced by Tympanic branch of Glossopharyngeal ~ in turn forms Tympanic Plexus
Lower part of anterior wall of Middle ear cavity is relating to
Inter Carotid Artery
Upper Part of Anterior wall of Middle Ear Cavity has
2 Bony Canals
1st for Tensor Tympani Muscle
2nd for Auditory Tube
Aditus is present in which wall of middle ear cavity
Posterior Wall
Through Aditus Middle ear is communicating with Mastoid Antrum
Pyramidal Eminence contains
Stapedial Muscle
Structures in Posterior Wall of Middle Ear
Aditus
Pyramidal eminence
Bony canal for Facial Nerve
Promontory in the medial wall of middle ear is due to
Basal Turn of Cochlea
Tympanic plexus is formed by
Is present over _________
Tympanic branch of IX
+
Caroticotympanic Branch (sympathetic plexus over ICA)
Oval window also known as
Fenestra Vestibuli
Fenestra Vestibuli is closed by
Foot plate of Stapes
Fenestra Cochlea is closed by
Fenestra Cochlea / Round Window
Is closed by Secondary Tympanic Membrane