saccule

(noun)

A bed of sensory cells situated in the inner ear that translates head movements into neural impulses that the brain can interpret.

Related Terms

Examples of saccule in the following topics:

  • The Vestibular System

    • There are five vestibular receptor organs in the inner ear, all of which help to maintain balance: the utricle, the saccule, and three semicircular canals.
    • The utricle and saccule are most responsive to acceleration in a straight line, such as gravity.
    • The roughly 30,000 hair cells in the utricle and 16,000 hair cells in the saccule lie below a gelatinous layer, with their stereocilia (singular: stereocilium) projecting into the gelatin.
    • Hair cells from the utricle, saccule, and semicircular canals also communicate through bipolar neurons to the cochlear nucleus in the medulla.
    • The structure of the vestibular labyrinth is made up of five vestibular receptor organs in the inner ear: the utricle, the saccule, and three semicircular canals.

  • Development of the Respiratory System

    • This surfactant is important in reducing the surface tension at the air-alveolar surface, allowing expansion of the terminal saccules.
    • Lastly, the alveolar period spans from birth to eight years of age and during this stage the terminal saccules, alveolar ducts, and alveoli increase in number.

  • Balance and Determining Equilibrium

    • Head position is sensed by the utricle and saccule, whereas head movement is sensed by the semicircular canals.
    • The utricle and saccule are both largely composed of macula tissue (plural = maculae).

  • Development of Hearing and Balance

    • They contain the sensory hair cells and otoliths of the macula of utricle and of the saccule, respectively, which respond to linear acceleration and the force of gravity.
    • The utricular division of the auditory vesicle also responds to angular acceleration, as well as the endolymphatic sac and duct that connect the saccule and utricle.

  • Vestibulocochlear (VIII) Nerve

    • The other two sensory organs supplied by the vestibular neurons are the maculae of the saccule and utricle.

  • Anatomy of the Large Intestine

    • The sacculations, called haustra, are characteristic features of the large intestine, and distinguish it from the small intestine.

  • Sensory Modalities

    • The vestibular nerve also conducts information from the utricle and the saccule; these contain hair-like sensory receptors that bend under the weight of otoliths (small crystals of calcium carbonate) that provide the inertia needed to detect head rotation, linear acceleration, and the direction of gravitational force.