NA4- Hearing

The Eustachian tube begins in close proximity to the carotid canal.

The stapes, the smallest bone in the body, is connected to the stapedius muscle.

The tensor tympani muscle is controlled by the facial nerve.

The acoustic reflex is the contraction of the stapedius and tensor tympani muscles in response to high-frequency sounds, protecting the inner ear.

The malleus, the first ossicle, is attached to the medial side of the tympanic membrane.

The head of the malleus enters the epitympanic cavity and articulates with the incus.

The chorda tympani, a branch of the facial nerve, passes through the epitympanic cavity.

The incus, shaped like a premolar tooth, has its short process located in the epitympanic cavity and its long process articulates with the stapes.

The base of the stapes transmits vibrations to the oval window of the cochlea, located on the medial wall of the tympanic cavity.

The skeletal muscles attached to the malleus and stapes have somatic motor fibers that control the transmission of sound, leading to amplification.

The sensory neurons forming the cochlear ganglion have their peripheral processes terminating at the hair cells of the organ of Corti, while their central processes contribute to the cochlear nerve.

Deiters cells, Hensen cells, and Claudius cells are all types of hair cells in the organ of Corti.

The tectorial membrane is firmly attached to the osseous spiral lamina, preventing movement of the stereocilia.

The inner hair cells are directly connected to the outer rods by extending obliquely through the tunnel formed by supportive cells.

The vibration of the perilymph causes vibrations in the basilar membrane, which results in deflection of the stereocilia of the hair cells.

The acoustic apparatus is responsible for collecting and analyzing light waves.

The tragus protects the external ear from internal and external pathogens by blocking the entrance to the external acoustic meatus.

The bony portion of the external ear consists of the temporal squama, while the skeletal portion is made of cartilage.

The auricle is responsible for transducing the sound waves into an electrochemical signal.

The vestibular system is connected to the acoustic system through the membranous system located inside the bony labyrinth.

The external acoustic meatus is a completely horizontal duct that conveys sounds towards the tympanic membrane.

The scala vestibuli and scala tympani are filled with endolymph, a fluid similar to the cerebrospinal fluid.

The tympanic membrane separates the middle ear from the inner ear.

The spiral lamina is present along the entire medial wall of the vestibule.

The middle ear is an liquid-filled chamber embedded in the petrous portion of the temporal bone.

The middle ear amplifies the vibrations collected by the tympanic membrane in order to overcome the impedance of the air.

The cochlear canal is divided by the basilar membrane.

The scala tympani and scala vestibuli are connected at the helicotrema, allowing perilymph to flow between them.

The endolymphatic duct connects the scala tympani and scala vestibuli to the subarachnoid space.

The scala media, filled with perilymph, is a blind-ending duct at the apex of the cochlea.

Each semicircular canal has an enlarged portion called ampulla containing receptors for the acoustic system.

The scala vestibuli communicates directly with the vestibule of the vestibular apparatus.

Endolymph has a higher concentration of potassium compared to sodium.

The tympanic cavity contains three small articulating bones known as the auditory ossicles.

The Eustachian tube serves to equalize pressure between the middle ear and the nasopharynx.

The tensor tympani muscle attaches to the stapes.

The chorda tympani nerve is a branch of the facial nerve and has a functional role in the middle ear.

The auditory canal is made up of the auricular cartilage and the tympanic cavity.

The two membrane-covered foramina present in the tympanic cavity are known as the oval window and the square window.

The Eustachian tube is primarily constructed of bone throughout its entire length.

Opening of the Eustachian tube can occur through actions like swallowing or yawning.

Fluid accumulation in the middle ear can drain into the nasopharynx via the Eustachian tube.

The tympanic cavity is located in the medial half of the pyramid.