Promontory Of Tympanic Cavity

	Promontory Of Tympanic Cavity The promontory of the tympanic cavity, also known as the cochlear promontory is a rounded hollow prominence upon - and most prominent feature of - the medial wall of the tympanic cavity formed by the underlying first turn of the cochlea. The surface of the promontory is furrowed by fine grooves that accommodate to the strands of the tympanic plexus. The oval window is situated superoposteriorly to the promontory, and the round window inferoposteriorly to it. A minute spicule of bone frequently connects the promontory to the pyramidal eminence The pyramidal eminence is a hollow conical projection upon the posterior wall of the tympanic cavity of the middle ear. The stapedius muscle arises in the hollow of the eminence and its tendon exits through its apex. The pyramidal eminence is si .... Additional images File:Gray913.png, Coronal section of right temporal bone. File:Gray914.png, The medial wall and part of the posterior and anterior walls of the right tympanic cavity, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Tympanic Cavity The tympanic cavity is a small cavity surrounding the bones of the middle ear. Within it sit the ossicles, three small bones that transmit vibrations used in the detection of sound. Structure On its lateral surface, it abuts the external auditory meatus (ear canal) from which it is separated by the tympanic membrane (eardrum). Walls The tympanic cavity is bounded by: * Facing the inner ear, the medial wall (or ''labyrinthic wall'', ''labyrinthine wall'') is vertical, and has the oval window and round window, the promontory, and the prominence of the facial canal. * Facing the outer ear, the lateral wall (or ''membranous wall''), is formed mainly by the tympanic membrane, partly by the ring of bone into which this membrane is inserted. This ring of bone is incomplete at its upper part, forming a notch (notch of Rivinus), close to which are three small apertures: the "iter chordæ posterius", the petrotympanic fissure, and the "iter chordæ anterius". The iter chordæ pos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Tympanic Plexus The tympanic plexus is a nerve plexus within the tympanic cavity formed upon the promontory of tympanic cavity by the tympanic nerve (branch of the inferior ganglion of glossopharyngeal nerve (CN IX)), and the superior and inferior caroticotympanic nerves (post-ganglionic sympathetic branches of the internal carotid plexus). The lesser petrosal nerve (which may be considered a continuation of the tympanic nerve) traverses the tympanic plexus. Anatomy Distribution The tympanic plexus innervates the mucosa of the tympanic cavity, pharyngotympanic tube, and mastoid air cell. It issues a branch to the greater petrosal nerve (through an opening anterior to the oval window The oval window (or ''fenestra vestibuli'' or ''fenestra ovalis'') is a connective tissue membrane-covered opening from the middle ear to the cochlea of the inner ear. Vibrations that contact the tympanic membrane travel through the three ossicl ...). References External links * () * {{Authority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Oval Window The oval window (or ''fenestra vestibuli'' or ''fenestra ovalis'') is a connective tissue membrane-covered opening from the middle ear to the cochlea of the inner ear. Vibrations that contact the tympanic membrane travel through the three ossicles and into the inner ear. The oval window is the intersection of the middle ear with the inner ear and is directly contacted by the stapes; by the time vibrations reach the oval window, they have been reduced in amplitude and increased in pressure due to the lever action of the ossicle bones. This is not an amplification function; rather, an impedance-matching function, allowing sound to be transferred from air (outer ear) to liquid (cochlea). It is a reniform (kidney-shaped) opening leading from the tympanic cavity into the vestibule of the inner ear; its long diameter is horizontal and its convex border is upward. It is occupied by the base of the ''stapes'', the circumference of which is fixed by the annular ligament to the margin of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Round Window The round window is one of the two openings from the middle ear into the inner ear. It is sealed by the secondary tympanic membrane (round window membrane), which vibrates with opposite phase to vibrations entering the inner ear through the oval window. It allows fluid in the cochlea to move, which in turn ensures that hair cells of the basilar membrane will be stimulated and that audition will occur. Structure The round window is situated below (inferior to) and a little behind (posterior to) the oval window, from which it is separated by a rounded elevation, the promontory. It is located at the bottom of a funnel-shaped depression (the round window niche) and, in the macerated bone, opens into the cochlea of the internal ear; in the fresh state it is closed by a membrane, the secondary tympanic membrane (, or ) or round window membrane, which is a complex saddle point shape. The visible central portion is concave (curved inwards) toward the tympanic cavity and convex (curve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Pyramidal Eminence The pyramidal eminence is a hollow conical projection upon the posterior wall of the tympanic cavity of the middle ear. The stapedius muscle arises in the hollow of the eminence and its tendon exits through its apex. The pyramidal eminence is situated inferior to the aditus to mastoid antrum, immediately inferior to the oval window (fenestra vestibuli), and anterior to the vertical portion of the facial canal. The apex of the eminence is directed anteriorly toward the oval window. The cavity in the pyramidal eminence is prolonged inferoposteriorly anterior to the facial canal, with which it communicates by a minute aperture which transmits the nerve to the stapedius from the facial nerve (CN VII). The space lateral to the pyramidal eminence is the facial recess, which is accessed during surgery for cochlear implant A cochlear implant (CI) is a surgically implanted Neuroprosthetics, neuroprosthesis that provides a person who has moderate-to-profound sensorineural hearing lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]