- 1. A ridge or margin apparently formed by the doubling back of a lamina. SYN: plica. 2. In the embryo, a transient elevation or reduplication of tissue in the form of a lamina.- alar folds of intrapatellar synovial f. [TA] winglike fat-filled lateral and medial fringes or expansions of the infrapatellar synovial f.. SYN: plicae alares plicae synovialis infrapatellaris.- amnionic f. a f. of amnionic membrane enclosing the yolk stalk and extending from the point of insertion of the umbilical cord to the yolk sac; in reptiles and birds it is the reflected edge of the amnion where it folds over to cover the embryo during early development. SYN: Schultze f..- ampullary folds of uterine tube one of the folds of mucous membrane at the fimbriated extremity of the uterine tube. SYN: plicae ampullares tubae uterinae.- anterior axillary f. bounds axilla anteriorly; formed by skin and fascia overlying inferior border of pectoralis major muscle.- aryepiglottic f. [TA] a prominent f. of mucous membrane stretching between the lateral margin of the epiglottis and the arytenoid cartilage on either side; it encloses the aryepiglottic muscle. SYN: plica aryepiglottica [TA], arytenoepiglottidean f..- axillary f. one of the folds of skin and muscular tissue bounding the axilla anteriorly and posteriorly. SYN: plica axillaris.- caval f. a f. near the base on the right side of the dorsal mesentery, in which a primordial segment of the inferior vena cava develops between the right subcardinal vein and vessels within the liver.- cecal folds [TA] the two peritoneal folds that border the retrocecal fossa. SYN: plicae cecales [TA].- f. of chorda tympani the f. of mucosa that surrounds the chorda tympani nerve in its course through the tympanic cavity. SYN: plica chordae tympani.- ciliary folds [TA] a number of low ridges in the furrows between the ciliary processes; together with the processes they constitute the corona ciliaris. SYN: plicae ciliares [TA].- circular folds of small intestine [TA] the numerous folds of the mucous membrane of the small intestine, running transversely for about two-thirds of the circumference of the gut. SYN: plicae circulares intestini tenuis [TA], Kerckring folds, Kerckring valves, valvulae conniventes.- Dennie-Morgan f. a f. or line below both lower eyelids caused by edema in atopic dermatitis. SYN: Dennie line.- dinucleotide f. a structural domain in certain proteins that binds NAD+ or NADP+. SYN: dinucleotide domain.- epicanthal f. SYN: palpebronasal f..- epiglottic folds one of the three folds of mucous membrane passing between the tongue and the epiglottis, lateral glossoepiglottic f. on either side, and median glossoepiglottic f. centrally. SYN: plicae epiglotticae.- falciform retinal f. a congenital f. from the disk to the ciliary region in the inferior temporal quadrant of the retina.- fatty folds of pleura lobules of fat enveloped in the pleura, chiefly in the neighborhood of the costomediastinal sinus. SYN: adipose folds of the pleura, plicae adiposae pleurae.- fimbriated f. of inferior surface of tongue [TA] one of several folds running outward from the frenulum on the undersurface of the tongue. SYN: plica fimbriata faciei inferioris linguae [TA].- gastric folds [TA] characteristic folds of the gastric mucosa, especially evident when the stomach is contracted. SYN: plicae gastricae [TA], gastric rugae, ruga gastrica, rugae of stomach.- gastropancreatic folds [TA] the folds of peritoneum in the omental bursa that encase the hepatic and left gastric arteries as these vessels pass toward their destinations. SYN: plicae gastropancreaticae [TA].- giant gastric folds enlarged gastric submucosal ridges covered by hyperplastic mucosa, as seen in Zollinger-Ellison syndrome, Ménétrièr disease, and hypertrophic hypersecretory gastropathy.- glossopalatine f. SYN: palatoglossal arch.- gluteal f. [TA] a prominent f. that marks the upper limit of the thigh from the lower limit of the buttock; it coincides with the lower border of the gluteus maximus muscle; the furrow between the buttock and thigh. SYN: sulcus gluteus [TA], gluteal furrow.- head f. a ventral folding of the cephalic extremity in the embryonic disk, so that the brain lies rostrad to the mouth and pericardium.- ileocecal f. [TA] a f. of peritoneum bounding the ileocecal or ileoappendicular fossa. SYN: plica ileocecalis [TA], Treves f..- incudal f. a variable f. of mucosa that passes from the roof of the tympanic cavity to the body and short limb of the incus. SYN: plica incudis.- inferior duodenal f. [TA] a f. of peritoneum bounding the inferior duodenal recess. SYN: plica duodenalis inferior [TA], duodenomesocolic f., plica duodenomesocolica.- infrapatellar synovial f. [TA] a f. of synovial membrane extending from below the level of the articular surface of the patella to the anterior part of the intercondylar fossa. SYN: plica synovialis infrapatellaris [TA], plica synovialis patellaris.- inguinal f. SYN: plica inguinalis.- interarytenoid f. the soft tissue between the arytenoid cartilages. SYN: posterior commissure of the larynx.- interdigital folds SYN: web of fingers/toes.- folds of iris [TA] numerous very fine, almost microscopic, radial folds on the posterior surface of the iris that extend around the pupillary margin. SYN: plicae iridis [TA].- labioscrotal folds lateral folds at either side of the embryonic cloacal membrane that develop into either the scrotum or the labia majora.- lacrimal f. [TA] a f. of mucous membrane guarding the lower opening of the nasolacrimal duct. SYN: plica lacrimalis [TA], Hasner f., Huschke valve, Rosenmüller valve.- lateral folds ventral foldings of the lateral margins of the embryonic disk, the development of which helps establish the definitive embryonic body form.- lateral glossoepiglottic f. [TA] the f. of mucous membrane that extends from the margin of the epiglottis to the pharyngeal wall and base of the tongue on each side, forming the lateral boundary of the epiglottic valleculae. SYN: plica glossoepiglottica lateralis [TA], pharyngoepiglottic f..- lateral umbilical f. [TA] the ridge on the peritoneal surface of the anterior abdominal wall formed by the inferior epigastric vessels. SYN: plica umbilicalis lateralis [TA], epigastric f., plica epigastrica.- f. of left vena cava [TA] a pericardial f. lying between the left oblique vein of the atrium and the left superior pulmonary vein containing the obliterated remains of the left superior vena cava. SYN: plica venae cavae sinistrae [TA], Marshall vestigial f., vestigial f..- longitudinal f. of duodenum [TA] a f. of mucosa on the medial wall of the descending part of the duodenum above the major duodenal papilla, probably caused by the relation to the common bile duct. SYN: plica longitudinalis duodeni [TA].- malar f. an ill-defined groove in the skin that extends downward and medially from the lateral canthus.- mallear folds [TA] two ligamentous bands, anterior and posterior, making folds on the tympanic side of the tympanic membrane extending from each extremity of the tympanic notch to the malleolar prominence; they mark the boundary between the tense and the flaccid portions of the tympanic membrane. SYN: plicae malleares (anterior et posterior) [TA], plica membranae tympani.- medial canthic f. palpebronasal f..- medial umbilical f. [TA] a f. of peritoneum on the lower part of the anterior abdominal wall that covers the obliterated umbilical artery on either side of the urachus. SYN: plica umbilicalis medialis [TA], plica hypogastrica.- median glossoepiglottic f. [TA] a f. of mucous membrane in the midline that extends from the back of the tongue to the epiglottis, forming the medial boundary of the epiglottic valleculae. SYN: plica glossoepiglottica mediana [TA], frenulum epiglottidis, middle glossoepiglottic f..- median umbilical f. [TA] a f. of peritoneum on the anterior wall of the abdomen covering the urachus, or remains of the allantoic stalk. SYN: middle umbilical f., plica urachi, urachal f..- mongolian f. SYN: palpebronasal f..- mucobuccal f. the line of flexure of the mucous membrane as it passes from the mandible or maxillae to the cheek.- mucosal folds of gallbladder [TA] the interlacing folds of the mucosa that produce a honeycomb appearance in the interior of the gallbladder. SYN: plicae mucosae vesicae biliaris [TA], rugae of gallbladder, rugae vesicae biliaris.- nasojugal f. a shallow groove in the skin that extends downward and laterally from the medial canthus.- opercular f. tissue forming a bridge or an adhesion between the tonsil and the anterior pillar of the fauces.- palmate folds of cervical canal the two longitudinal ridges, anterior and posterior, in the mucous membrane lining the cervix uteri, from which numerous secondary folds, or rugae, branch off. SYN: plicae palmatae canalis cervicis uteri [TA], arbor vitae uteri, lyra uterina.- palpebronasal f. [TA] a f. of skin extending from the root of the nose to the medial termination of the eyebrow, overlapping the medial angle of the eye; its presence is normal in fetal life and in some Asians. SYN: plica palpebronasalis [TA], medial canthic f., epicanthal f., epicanthus, mongolian f..- paraduodenal f. [TA] a sickle-shaped f. of peritoneum sometimes found arching between the left side of the duodenojejunal flexure and the medial border of the left kidney; its right free edge contains the ascending branch of the left colic artery and inferior mesenteric vein; forms anterior boundary of the paraduodenal recess. SEE ALSO: paraduodenal recess. SYN: plica paraduodenalis [TA], Treitz arch.- pharyngoepiglottic f. SYN: lateral glossoepiglottic f..- pleuropericardial f. a tissue f. jutting into the right or left embryonic pericardioperitoneal canal; it separates the developing pericardium from the pleural cavity and is formed by the growth of the common cardinal veins to the midline of the body. SYN: pericardiopleural membrane, pleuropericardial membrane.- pleuroperitoneal f. a tissue f. jutting into the caudal portion of the embryonic pericardioperitoneal canal; it develops into the dorsal portion of the definitive diaphragm and is formed by the lungs growing caudally and the liver expanding cranially. SYN: pleuroperitoneal membrane.- posterior axillary f. bounds axilla posteriorly; formed by skin and fascia overlying latissimus dorsi and teres major muscles and tendons of insertion.- presplenic f. a fan-shaped f. of peritoneum that passes from the gastrosplenic ligament near the lower end of the spleen to the phrenicocolic ligament with which it blends. It contains branches of the splenic or the left gastroepiploic artery.- rectouterine f. [TA] a f. of peritoneum, containing the rectouterine muscle, passing from the sacrum to the base of the broad ligament on either side, forming the lateral boundary of the rectouterine (Douglas) pouch. SYN: plica rectouterina [TA], Douglas f., sacrouterine f..- rectovesical f. SYN: sacrovesical f..- retinal f. a congenital or secondary f., consequent to membrane contraction, producing star-shaped, meridional, or circular folds on the retina.- Rindfleisch folds semilunar folds of the serous surface of the pericardium, embracing the beginning of the aorta.- sacrogenital folds peritoneal folds that extend backward from the sides of the bladder of the male or uterus of the female on either side of the rectum to the sacrum, forming the lateral boundaries of the rectovesical pouch. See sacrouterine f., sacrovesical f..- sacrouterine f. SYN: rectouterine f..- sacrovaginal f. the lower part of the sacrouterine f.. SYN: plica rectovaginalis.- sacrovesical f. the f. of peritoneum in the male that bounds the rectovesical pouch laterally. SYN: rectovesical f..- salpingopalatine f. [TA] a ridge of mucous membrane passing from the anterior border of the opening of the auditory (eustachian) tube to the palate. SYN: plica salpingopalatina [TA], plica tubopalatina.- salpingopharyngeal f. [TA] a ridge of mucous membrane extending from the lower end of the tubal elevation along the wall of the pharynx overlying the salpingopharyngeus muscle. SYN: plica salpingopharyngea [TA].- semilunar f. [TA] inconsistent curved f. connecting the palatoglossal arch and palatopharyngeal arch above the supratonsillar fossa; when present, it always contains lymphoid tissue. SYN: plica semilunaris [TA].- semilunar folds of colon [TA] one of the folds of the wall of the colon between sacculations. SYN: plicae semilunares coli [TA], plicae semilunares of colon.- spiral f. of cystic duct [TA] a series of crescentic folds of mucous membrane in the upper part of the cystic duct, arranged in a somewhat spiral manner. SYN: plica spiralis ductus cystici [TA], Amussat valve, Heister valve, spiral valve of cystic duct, valvula spiralis.- f. of stapes [TA] a reflection of the delicate mucous membrane from the posterior wall of the tympanic cavity that covers the stapes. SYN: plica stapedialis, stapedial f..- sublingual f. [TA] an elevation in the floor of the mouth beneath the tongue, on either side, marking the site of the sublingual gland. SYN: plica sublingualis [TA].- superior duodenal f. [TA] a f. of peritoneum bounding the superior duodenal recess. SYN: plica duodenalis superior [TA], duodenojejunal f., plica duodenojejunalis.- f. of superior laryngeal nerve [TA] the slight f. of mucosa in the piriform recess of the pharynx that encloses the superior laryngeal nerve. SYN: plica nervi laryngei superioris [TA], f. of laryngeal nerve.- synovial f. a ridge or projection of the synovial membrane of a joint extending toward or between the two articular surfaces. SYN: plica synovialis.- tarsal f. the f. marking the attachment of the levator palpebrae superioris muscle into the skin of the upper eyelid.- transverse palatine f. [TA] a masticatory vestige on the hard palate; one of several irregular, sometimes branching, crests of soft tissue that radiate from the region of the incisive papillae at their most anterior parts and extend a slight distance backward, crossing the hard palate and reaching laterally for variable distances. SYN: plica palatina transversa [TA], ruga palatina, transverse palatine ridge.- transverse folds of rectum [TA] the three or four crescentic folds placed horizontally in the rectal mucous membrane; the superior rectal f. is situated near the beginning of the rectum on the left side; the middle rectal f. (Houston or Kohlrausch f.) is most prominent and consistent and projects from the right side about 8 cm above the anus (approximately the level of the floor of the rectouterine or rectovesical pouch); the inferior rectal f. is on the left side about 5 cm above the anus. SYN: plicae transversales recti [TA], Houston folds, Kohlrausch folds, plicae recti, rectal folds, rectal valves.- transverse vesical f. a duplication of peritoneum passing over the empty bladder, but obliterated when the viscus is full. SYN: plica vesicalis transversa.- triangular f. [TA] an inconstant f. of mucous membrane anterior to the palatine tonsil arising from the palatoglossal arch. SYN: plica triangularis [TA].- folds of uterine tubes [TA] many longitudinal folds in the mucous membrane of the uterine (fallopian) tube. SYN: plicae tubariae tubae uterinae [TA].- vascular f. of the cecum [TA] a peritoneal f. that arches over a branch of the ileocolic artery and bounds in front a narrow recess, the superior ileocecal (or ileocolic) recess. SYN: plica cecalis vascularis [TA].- vestibular f. [TA] one of the pair of folds of mucous membrane overlying the vestibular ligaments that stretch across the laryngeal cavity from the angle of the thyroid cartilage to the arytenoid cartilage; the right and left pair enclose a space called the rima vestibuli or false glottis, and form the superior boundary of the laryngeal ventricle. SYN: plica vestibularis [TA], false vocal cord, plica ventricularis, ventricular band of larynx, ventricular f..- vocal f. [TA] the sharp-edged f. of mucous membrane overlying the vocal ligament and stretching along either wall of the larynx from the angle between the laminae of the thyroid cartilage to the vocal process of the arytenoid cartilage; the vocal folds are the agents concerned in voice production. SYN: plica vocalis [TA], chorda vocalis, Ferrein cords, labium vocale, true vocal cord, vocal cord, vocal shelf.
* * *fold 'fōld vi to become doubled or pleatedfold n a margin apparently formed by the doubling upon itself of a flat anatomical structure (as a membrane)
* * *n.(in anatomy and embryology) the infolding of two surfaces or membranes.
* * *(fōld) a thin, recurved margin, or doubling over; called also plica.
For descriptions of specific anatomic structures not found here, see under plica.
Medical dictionary. 2011.