Membranous Labryinth (Vestibular System: Basic Anatomy & Physiology) Flashcards
What are the membranous ampullae? What do they contain?
Correspond in location to the osseous ampullae. Contain sensory organ for each canal, which is the crista ampularis.
What is the Crista ampularis made of?
Supporting membrane, the cupula (gelatinous portion with embedded hair cells), and sensory hair cells.
How do sensory hair cells move inside of the crista ampularis?
Stereocilia deflect with movement of fluid- hair cell is depolarized if stereocilia are bent toward kinocilia & hyperpolarized if bent away.
What is the Crista ampularis responsible for?
Detecting dynamic equilibrium (sensing angular movements of the head). As head rotates, the fluid in the semicircular canals lags behind and will excite or inhibit the hair cells depending on the direction of movement.
Where are the Utricle and Saccule housed?
Within the osseous vestibule.
What do the Utricle and Saccule house?
Contain macula, the sensory organ for the utricle & saccule.
What is macula made of?
Similar to Crista ampularis- made of supporting membrane (epithelial cells), otolithic membrane (gelatinous portion overlaying the stereocilia of the hair cells), and sensory hair cells.
How is the otolithic membrane different from the cupula?
Otolithic membrane containes otoconia/otoliths- calcium carbonate crystals that provide mass to the otolithic membrane and make it responsive to gravity.
Describe the sensory hair cells of macula…
Similar to Crista ampularis, hair cells deflect with movement of surrounding fluid. Also contains a kinocilium.
What do the maculae detect?
Static equilibrium- senses linear movements, acceleration of head in the vertical and horizontal directions (movements of the body relative to the forces of gravity).
What are the membranous semicircular canals?
Similar in shape to the osseous semicircular canals, with 5 openings into the utricle (in the vestibule).
