Exercise 25 Review Sheet Art-Labeling Activity 1 (2024)

FAQs

What is the role of the endolymph of the semicircular ducts? ›

The vestibular apparatus is composed of the utricle, saccule, and three semicircular ducts. The acceleration of endolymph within regions of the vestibular apparatus allows for our perception of balance and equilibrium.

The middle ear contains three tiny bones collectiely known as the ear ossicles namely, malleus, incus, and stapes. The ossicles were given their names based on their distinctive shapes.

In the middle ear, the ear ossicle malleus transmits the sound vibration to the incus which in turn transmits it to the stapes. The stapes passes the sound vibration to the oval window of the cochlea. This leads to movement of fluid within the cochlea and activation of receptors for hearing.

The mechanical vibrations of the stapes footplate at the oval window creates pressure waves in the perilymph of the scala vestibuli of the cochlea. These waves move around the tip of the cochlea through the helicotrema into the scala tympani and dissipate as they hit the round window.

The semicircular canals are three tiny, fluid-filled tubes in the inner ear that help you keep your balance.

Endolymph function? The endolymph of the semicircular canals serves a function analogous to that of the otolithic membrane—it provides inertia so that the sensory processes will be bent in a direction opposite to that of the angular acceleration.

The auditory ossicles are located in the middle ear, which is the portion of the ear between the external part of the ear, formed by the auricle, or pinna, and the ear canal; and the inner ear, which contains the cochlea, and semicircular canals.

The middle ear contains three small ossicles: the hammer (or malleus), the anvil (or incus), and the stirrup (or stapes).

Behind the eardrum are the tympanic cavities, which contain the three auditory ossicles: the malleus, incus, and stapes. This area is called the middle ear (Fig. 2.4). The sound pressure striking the eardrum is transduced into vibration.

The vibrations from the eardrum set the ossicles into motion. The ossicles are actually tiny bones — the smallest in the human body. The three bones are named after their shapes: the malleus (hammer), incus (anvil) and stapes (stirrup). The ossicles further amplify the sound.

How many ossicles are found in the ear? ›

The ossicles (also called auditory ossicles) are three bones in either middle ear that are among the smallest bones in the human body. They serve to transmit sound vibrations sent from the ear drum to the fluid-filled labyrinth (cochlea).

Eustachian tube.

A canal that links the middle ear with the back of the nose. The eustachian tube helps to equalize the pressure in the middle ear. Having the same pressure allows for the proper transfer of sound waves. The eustachian tube is lined with mucous, just like the inside of the nose and throat.

Hair cells—sensory cells sitting on top of the basilar membrane—ride the wave. Hair cells near the wide end of the snail-shaped cochlea detect higher-pitched sounds, such as an infant crying. Those closer to the center detect lower-pitched sounds, such as a large dog barking.

Two membranes separate the cochlear duct proper, which is also known as the scala media, from the scala tympani and scala vestibule. The basilar membrane demarcates the scala media from the scala tympani, while the vestibular membrane separates the scala media from the scala vestibule.

Sound waves picked up by the external ear vibrate the eardrum, which in turn mobilizes the ossicular chain of the middle ear. The footplate of the stapes applies a mechanic pressure on the oval window and the vibration reaches the perylymphatic fluid of the cochlea.

The physiology of the endolymphatic sac and its role in longitudinal endolymph flow. The ELS has absorptive and secretory functions as well as phagocytic and immune defence functions. It has been known for many years that debris placed into the cochlear duct passes to the ELS.

The three semicircular canals are endolymph-filled rings specialized to detect angular acceleration. Each canal has a swelling, called the ampulla (Figure 1(c)), which contains the mechanoreceptive epithelium (the ampullary crista). In humans, each crista bears about 7000 hair cells.

Located in the inner ear, the semicircular canals are three very small tubes whose primary job is to regulate balance and sense head position.

The semicircular canals are activated by circular motion and are filled with endolymph. The motion of the fluid informs the brain whether one is moving.