inner ear

Examples of inner ear in the following topics:

• Audition: Hearing, the Ear, and Sound Localization

  • The main sensory organ responsible for the ability to hear is the ear, which can be broken down into the outer ear, middle ear, and inner ear.
  • The inner ear contains the receptor cells necessary for both hearing and equilibrium maintenance.
  • The middle ear is an air-filled tympanic (drum-like) cavity that transmits acoustic energy from the ear canal to the cochlea in the inner ear.
  • Through these steps, the middle ear acts as a gatekeeper to the inner ear, protecting it from damage by loud sounds.
  • Unlike the middle ear, the inner ear is filled with fluid.

• Vestibulocochlear (VIII) Nerve

  • This is the nerve along which the sensory cells (the hair cells) of the inner ear transmit information to the brain.
  • It emerges from the pons and exits the inner skull via the internal acoustic meatus (or internal auditory meatus) in the temporal bone.
  • The cochlear nerve travels away from the cochlea of the inner ear where it starts as the spiral ganglia.
  • The vestibular nerve travels from the vestibular system of the inner ear.
  • An illustration of the inner ear showing its semicircular canal, hair cells, ampulla, cupula, vestibular nerve, and fluid.

• Reception of Sound

  • The outer, middle, and inner structures of the ear collect sound energy, converting it to audible sound.
  • the inner ear: interprets the electrical signals from the middle ear using hair cells
  • Interior to the tympanum is the middle ear, which holds three small bones called the ossicles ("little bones"), that transfer energy from the moving tympanum to the inner ear.
  • If we did not have the malleus and the incus, then the vibrations of the tympanum would never reach the inner ear.
  • The middle ear contains three bones called ossicles that transfer the sound wave to the oval window, the exterior boundary of the inner ear.

• The Ear

  • Air surrounds the head and fills the ear canal and middle ear.
  • Therefore, when the outer part of the ear collects sound and the middle ear amplifies this sound pressure, these processes occur in the medium of air.
  • However, the hollow channels of the inner ear (which is embedded in the temporal bone, the densest bone of the body) are filled with liquid.
  • So as the sound travels into the inner ear, it passes from the medium of air into a liquid medium.
  • These inner-ear channels contain a sensory epithelium that is studded with hair cells.

• Characteristics and Evolution of Amphibians

  • Amphibians evolved from fish 400 million years ago and are characterized by four limbs, moist skin, and sensitive inner ear structures.
  • Additional characteristics of amphibians include pedicellate teeth (teeth in which the root and crown are calcified, separated by a zone of noncalcified tissue) and a papilla amphibiorum and papilla basilaris (structures of the inner ear that are sensitive to frequencies below and above 10,00 hertz, respectively).
  • Amphibians also have an auricular operculum, which is an extra bone in the ear that transmits sounds to the inner ear.

• Balance and Determining Equilibrium

  • With hair cells in the inner ear that sense linear and rotational motion, the vestibular system determines equilibrium and balance states.
  • Along with audition, the inner ear is responsible for encoding information about equilibrium, or the sense of balance.
  • These cells are located within the vestibule of the inner ear.

• Human Perception of Sound

  • The human ear is made up of three main sections, as shown in :
  • When you look at someone's ear, you are really only seeing the pinna, the outer most portion of the ear.
  • The wave then goes through your ear canal to the eardrum.
  • This is the beginning of the inner ear.
  • The sound waves are then transmitted from the elliptical window through the inner ear's semicircular canals, the cochlea, and the audio nerve, which is filled with fluid.

• Transduction of Sound

  • The stapes transmits the vibrations to a thin diaphragm called the oval window, which is the outermost structure of the inner ear.
  • The structures of the inner ear are found in the labyrinth, a bony, hollow structure that is the most interior portion of the ear.
  • Place theory, which is the model for how biologists think pitch detection works in the human ear, states that high frequency sounds selectively vibrate the basilar membrane of the inner ear near the entrance port (the oval window).
  • The inner ear can be divided into three parts: the semicircular canals, the vestibule, and the cochlea, all of which are located in the temporal bone.
  • The middle ear exists between the tympanic membrane (the boundary with the outer ear) and the oval window (the boundary with the inner ear) and consists of three bones: the malleus (meaning hammer), the incus (meaning anvil), and the stapes (meaning stirrup).

• Characteristics of Mammals

  • Mammalian traits include, among others: specialized glands, modified jaw and inner ear bones, urinary bladder, and hair.
  • These bones are present in mammals, but they have been modified to function in hearing and form bones in the middle ear .
  • Other vertebrates possess only one middle ear bone, the stapes.
  • This arrangement of jaw and ear bones aids in distinguishing fossil mammals from fossils of other synapsids.
  • Bones of the mammalian inner ear are modified from bones of the jaw and skull.

• Otitis Media

  • Otitis media is inflammation of the middle ear .
  • It occurs in the area between the tympanic membrane and the inner ear, also effecting a duct known as the eustachian tube.
  • Diseases other than ear infections can also cause ear pain, including various cancers of any structure that share nerve supply with the ear.
  • After a few days of a stuffy nose, the ear becomes involved and can cause severe pain.
  • Sometimes the ear drum ruptures, discharging pus from the ear, but the ruptured drum will usually heal rapidly.