THE_ESPECIAL_SENSES_OF_HEARING_AND_BALANCE_OR_EQUILIBRIUM

Special Senses

Refers to the senses of hearing and balance, also known as equilibrium, which are crucial for perception and orientation.

Auricle

Also known as the pinna, it is the visible part of the external ear that collects and channels sound waves.

Tympanic Membrane

A thin, semitransparent sheet at the end of the auditory canal that vibrates when sound waves strike it, transmitting the sound waves to the middle ear.

Auditory Ossicles

Three tiny bones in the middle ear - Malleus (hammer), Incus (anvil), and Stapes (stirrup) - that conduct and amplify vibrations of the tympanic membrane to the inner ear.

Vestibulocochlear Nerve

Also known as Cranial Nerve VIII, it is responsible for transmitting sound and equilibrium information from the inner ear to the brain.

Cochlea

A spiral-shaped structure in the inner ear that contains the cochlear duct with receptors for the sense of hearing.

Equilibrium

The state of physical balance provided by the vestibular complex, including the vestibule and semicircular canals, which sense gravity, linear acceleration, and rotational movement for static and dynamic equilibrium.

Perilymph

The fluid that cushions the membranous labyrinth in the inner ear and flows between the bony and membranous labyrinths.

Endolymph

The fluid that flows within the membranous labyrinth of the inner ear, providing the environment for receptor cells and sensory information.

Semicircular Canals

Three fluid-filled tubes in the inner ear that detect rotational movement of the head and contribute to the sense of dynamic equilibrium.

Semicircular Ducts

Structures in the inner ear responsible for detecting rotational movements and maintaining balance.

Ampulla

A dilated portion of the semicircular ducts filled with endolymph.

Hair cells

Sensory receptors located in the ampulla that detect movement.

Ampullary cupula

Gelatinous structure in the ampulla that moves in response to endolymph movement.

Macula

Structure in the saccule and utricle containing hair cells responsible for sensing linear movement and position.

Otoliths

Crystals of calcium carbonate in the macula that add weight and aid in detecting gravity and linear acceleration.

Vestibular ganglia

Neurons that monitor hair cells in the vestibular complex and send signals to the brain for balance and equilibrium.

Otoliths

Also known as ear stones, these crystals in the macula respond to gravity and linear acceleration.

Basilar membrane

Separates the cochlear duct from the scala tympani and contains sensory receptors for hearing.

Tectorial membrane

Overlying membrane that contacts the stereocilia of the hair cells in the organ of Corti.

Cochlea

A spiral-shaped, fluid-filled structure in the inner ear responsible for hearing.

Basilar membrane

Membrane within the cochlea that plays a crucial role in sound perception by vibrating in response to sound waves.

Organ of Corti

Structure within the cochlear duct containing sensory receptors for hearing.

Tectorial membrane

Membrane above the hair cells in the Organ of Corti that plays a role in hearing by interacting with the cilia of the hair cells.

Vestibular membrane

Membrane that separates the cochlear duct from the vestibular duct in the cochlea.

Cochlear nerve

Nerve that transmits auditory information from the cochlea to the brain.

Vestibulocochlear nerve

Cranial nerve VIII responsible for transmitting sound and balance information from the inner ear to the brain.

Endolymph

Fluid filling the cochlear duct in the inner ear.

Perilymph

Fluid filling the scala vestibuli and scala tympani in the cochlea.