What is sinus tympani?
The sinus tympani (ST) is a critical anatomic region of the temporal bone. It lies medial to the facial nerve, between the ponticulus and the subiculum, and therefore is not easily visualized by routine surgical approaches to the middle ear and mastoid.
What structures are located in the tympanic cavity?
The tympanic cavity, an air filled space in the temporal bone, lies beyond the ear drum. In it are housed three articulated bones, the malleus, the incus and the stapes, known collectively as the ossicular chain.
What connects the tympanic membrane to the nasal cavity?
Overview. The eustachian tube (pharyngotympanic tube) connects the middle ear cavity with the nasopharynx.
Where is the tensor tympani muscle located?
the middle ear
Tensor tympani is a tiny, but long paired muscle of the middle ear. Together with the stapedius, it belongs to the group of intratympanic muscles. Tensor tympani occupies a bony canal found superior to the osseous part of the auditory tube (pharyngotympanic tube; Eustachian tube).
What is the Mesotympanum?
The hypotympanum is defined as the area of the middle ear inferior to the tympanic membrane, while the mesotympanum covers the region of the middle ear medial to the tympanic membrane, and the epitympanum the superior aspect of the tympanic membrane.
What is posterior tympanotomy?
Posterior tympanotomy is the avenue to the facial recess of the middle ear from mastoid antrum. The entry into the facial recess in many cases is heralded by a distinct air cell before approaching the facial-chordal plane.
What is the tympanic cavity for?
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.
Is the tympanic membrane in the cochlea?
When a sound is made outside the outer ear, the sound waves, or vibrations, travel down the external auditory canal and strike the eardrum (tympanic membrane). They send the sound waves to the inner ear and into the fluid-filled hearing organ (cochlea).
What is the tympanic antrum?
The mastoid antrum (plural: mastoid antra) (also known as tympanic antrum or Valsalva antrum) is an air space (up to 1 cm in size) lying posterior to the middle ear and connected to it by a short passageway, the aditus ad antrum.
What cranial nerve Innervates tensor tympani?
fifth cranial nerve
The tensor tympani is innervated by a branch of the fifth cranial nerve, whereas the stapedius is innervated by a branch of the seventh cranial nerve. The muscles receive a dense innervation from motor neurons.
What are the stapedius and tensor tympani?
The tensor tympani and stapedius muscles are protective reflexes. They reduce the amount of sound that gets into the inner ear. They are somewhat similar to the blink reflex. Thus they can be triggered by loud noise, and when they “go off”, both ears can be involved.