| vitelline sac | <embryology, ornithology> One of the set of extra embryonic membranes, growing out from the gut over the yolk surface, in birds formed from the splanchnopleure, an outer layer of splanchnic mesoderm and an inner layer of endoderm. (18 Nov 1997) |
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| vitelline | <biology> Of or pertaining to the yolk of eggs; as, the vitelline membrane, a smooth, transparent membrane surrounding the vitellus. Origin: L. Vitellus the yolk of an egg. Source: Websters Dictionary (01 Mar 1998) |
| vitelline artery | <anatomy, artery> An artery carrying blood to the yolk sac from the embryo. Synonym: arteria vitellina. (05 Mar 2000) |
| vitelline cord | A persistent yolk stalk in the form of a solid cord of tissue connecting ileum to umbilicus. Synonym: omphalomesenteric cord. (05 Mar 2000) |
| vitelline duct | The narrow tube connecting the yolk sac with the midgut of the embryo; persistence of all or part of it in post-foetal life produces abnormalities, of which the commonest is meckel's diverticulum. (12 Dec 1998) |
| vitelline fistula | A fistula between the umbilicus and the terminal ileum along the course of a persistent vitelline cord. See: Meckel's diverticulum. (05 Mar 2000) |
| vitelline layer of egg | <zoology> The membrane, usually of protein fibres, immediately outside the plasmalemma of the ovum and the earlier stages of the developing embryo. Its structure and composition vary in differing animal groups. (18 Nov 1997) |
| vitelline membrane | <cell biology> The plasma membrane of the egg. (12 Dec 1998) |
| Vitelline pole | <embryology> The vegetative pole of an ovum. (05 Mar 2000) |
| vitelline reservoir | In cestodes and trematodes, a common chamber receiving vitelline (yolk) material from the two vitelline ducts; the yolk material then passes into the ootype to surround the ovum with nutritive vitelline granules that are enclosed by a characteristically formed eggshell. Synonym: vitelline reservoir. (05 Mar 2000) |
| vitelline vein | <anatomy, vein> A vein returning blood from the yolk sac to the embryo. Synonym: vena vitellina. (05 Mar 2000) |
| vitelline vessels | See: vitelline artery, vitelline vein. (05 Mar 2000) |
| absent distal clavicle | <radiology> Cleidocranial dysostosis, rheumatoid arthritis, hyperparathyroidism (12 Dec 1998) |
| articular disc of distal radioulnar joint | The disk that holds together the distal ends of the radius and ulna; it is attached by its apex to a depression between the styloid process and distal surface of the head of the ulna, and by its base to the ridge separating the ulnar notch from the carpal surface of the radius. Synonym: discus articularis radioulnaris, radioulnar disk, radioulnar articular disk, triangular cartilage, triangular disk of wrist, triquetrous cartilage. (05 Mar 2000) |
| symmetric distal neuropathy | <neurology> A disease process involving a number of peripheral nerves. Origin: Gr. Pathos = disease (14 Oct 1997) |