otocystn.
/ˈəʊtə(ʊ)sɪst/, U.S. /ˈoʊdəˌsɪst/, /ˈoʊdoʊˌsɪst/ Zoology and Embryology.
In certain invertebrates: a small organ containing calcareous particles and functioning in the maintenance of balance and orientation (= statocyst n. at stato- comb. form 3). Also: the embryonic precursor of the inner ear in vertebrates.
ΘΚΠ
the world > animals > invertebrates > bodies or parts > [noun] > ear
otocyst1874
1874 Proc. Royal Soc. 1873–4 22 232 The origin of the otocysts by invagination.
1877 T. H. Huxley Man. Anat. Invertebrated Animals iv. 189 In some there is a sac filled with calcareous matter (otocyst?) attached to the ganglion.
1878 F. J. Bell & E. R. Lankester tr. C. Gegenbaur Elements Compar. Anat. 533 The primitive otocyst is the foundation of a complicated cavitary system.
1906 C. S. Sherrington Integrative Action Nerv. Syst. ix. 334 The free-swimming Ascidia with fin-like motor organs and semi-rigid aerial notochord..bears at its anterior end a well-formed photo-receptor organ (eye) and a well-formed otocyst (head proprio-ceptor).
1930 H. G. Newth Marshall & Hurst's Junior Course Pract. Zool. (ed. 11) vii. 110 The ‘auditory’ organ, statocyst or otocyst, which lies a little behind and below the ganglion, is innervated from the cerebral ganglion.
1958 J. E. Morton Molluscs viii. 148 Embedded in the foot are simple otocysts with calcareous otoconia.
1965 L. B. Arey Developmental Anat. (ed. 7) xxvii. 541 In embryos of about 24 somites..the cup-like pits close into otocysts which soon lose their union with the ectoderm and become detached as ovoid sacs.
1986 A. S. Romer & T. S. Parsons Vertebr. Body (ed. 6) ii. 23 (caption) The otocyst is a simple ear structure.
2000 Anat. & Embryol. 202 333 Formation of the otocyst from the otic placode appears to differ from invagination of other cup-shaped organ primordia.
Derivatives
otoˈcystic adj.
ΘΚΠ
the world > animals > invertebrates > bodies or parts > [adjective] > of or connected with ear
otocystic1876
1876 Philos. Trans. 1875 (Royal Soc.) 165 18 This first rudiment of the otocyst developing in the epiblast may be termed the ‘otocystic vacuole’.
1923 Philos. Trans. (Royal Soc.) B. 211 117 Even the skull itself may have spinous protuberances (otocystic spines, Lepidorhombus, etc.).
1987 Differentiation 35 151 Cells in the early otic ganglion were also positively labelled for cytokeratins, suggesting that they are of otocystic epithelial origin.
This entry has been updated (OED Third Edition, September 2004; most recently modified version published online March 2022).
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n.1874