Biomaterial Database

A scanning electron microscopy study on human otoconia genesis. 1984

J M Sánchez-Fernández, and J M Rivera-Pomar

The genesis of the otoconia was studied with SEM in several human fetuses. The results of the present paper together with previous reports (1, 2, 13) support the hypothesis that otoconia genesis may develop according the following stages: (1) calcification of some sensory and supporting cells; (2) extrusion of the calcified cellular material and some organic substances in "sponge-like bodies"; (3) deposition of diverse core seeds in these areas giving rise to a random calcium carbonate crystallization and incorporation of matrix organic material; (4) growth of otoconia developing linearly with a gradual change in shape from spherical to ovoid, rhombohedral, and cylindrical forms; (5) inhibition of crystal growth occurring once a critical unsaturated calcium endolymph state and an adequate size of statoconial membranous chambers are reached.

UI	MeSH Term	Description	Entries
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D010037	Otolithic Membrane	A gelatinous membrane overlying the acoustic maculae of SACCULE AND UTRICLE. It contains minute crystalline particles (otoliths) of CALCIUM CARBONATE and protein on its outer surface. In response to head movement, the otoliths shift causing distortion of the vestibular hair cells which transduce nerve signals to the BRAIN for interpretation of equilibrium.	Otoconia,Otoliths,Statoconia,Membrane, Otolithic,Membranes, Otolithic,Otoconias,Otolith,Otolithic Membranes,Statoconias
D005865	Gestational Age	The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated from the onset of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization. It is also estimated to begin from fertilization, estrus, coitus, or artificial insemination.	Embryologic Age,Fetal Maturity, Chronologic,Chronologic Fetal Maturity,Fetal Age,Maturity, Chronologic Fetal,Age, Embryologic,Age, Fetal,Age, Gestational,Ages, Embryologic,Ages, Fetal,Ages, Gestational,Embryologic Ages,Fetal Ages,Gestational Ages
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012444	Saccule and Utricle	Two membranous sacs within the vestibular labyrinth of the INNER EAR. The saccule communicates with COCHLEAR DUCT through the ductus reuniens, and communicates with utricle through the utriculosaccular duct from which the ENDOLYMPHATIC DUCT arises. The utricle and saccule have sensory areas (acoustic maculae) which are innervated by the VESTIBULAR NERVE.	Otolithic Organs,Utricle,Saccule,Organ, Otolithic,Otolithic Organ,Saccules,Utricle and Saccule,Utricles