- A fissure.- branchial clefts a bilateral series of slitlike openings into the pharynx through which water is drawn by aquatic animals; in the walls of the clefts are the vascular gill filaments that take up oxygen from the water passing through the clefts; sometimes loosely applied to the branchial ectodermal grooves of mammalian embryos, which are imperforate, rudimentary homologues of complete gill clefts. SYN: gill clefts.- cholesterol c. a space caused by the dissolving out of cholesterol crystals in sections of tissue embedded in paraffin.- facial c. a c. resulting from incomplete merging or fusion of embryonic processes normally uniting in the formation of the face, e.g., c. lip or c. palate. SYN: prosopoanoschisis.- first visceral c. SYN: hyomandibular c..- gill clefts SYN: branchial clefts.- gingival c. a fissure associated with pocket formation and lined by mixed gingival and pocket epithelium.- hyomandibular c. the c. between the hyoid and mandibular arches of the embryo; the external auditory meatus is developed from its dorsal portion. SYN: first visceral c..- intergluteal c. [TA] the sulcus between the buttocks (nates). SYN: crena analis [TA], crena ani, crena interglutealis, natal c., anal c., crena clunium, gluteal c..- interneuromeric clefts clefts between the neuromeric or segmental elevations in the primitive rhombencephalon.- Larrey c. SYN: trigonum sternocostale.- laryngotracheoesophageal c. absence of fusion of the musculature or cricoid cartilaginous laminae of varying severity: type 1, submucous c. of the interarytenoid muscles (known also as occult posterior laryngeal c. or submucous laryngeal c.); type 2, partial cricoid c. (known also as partial posterior laryngeal c.); type 3, total cricoid c. (known also as laryngotracheoesophageal c. or total cricoid c.); and type 4, extension of the c. into the esophagus.- median maxillary anterior alveolar c. an asymptomatic midline defect of the maxillary anterior ridge; the result of a failure of fusion or development of the lateral halves of the palate.- partial cricoid c. See laryngotracheoesophageal c..- pudendal c. [TA] the c. between the labia majora. SYN: rima pudendi [TA], fissura pudendi, pudendal cleavage, pudendal slit, rima vulvae, urogenital c., vulvar slit.- residual c. the remnants of the pituitary diverticulum that occur between the pars distalis and pars intermedia; a distinct lumen is present in some animals, but, in humans, is present only during prenatal development and sometimes in young children. SYN: residual lumen.- synaptic c. the space about 20 nm wide between the axolemma and the postsynaptic surface. SEE ALSO: synapse.- total cricoid c. See laryngotracheoesophageal c..
* * *cleft 'kleft n1) a usu. abnormal fissure or opening esp. when resulting from failure of parts to fuse during embryonic development2) a usu. V-shaped indented formation: a hollow between ridges or protuberances <the anal \cleft of the human body>3) the hollow space between the two branches of the frog or the frog and bars or between the bulbs of the heel of a horse's hoof4) a crack on the bend of the pastern of a horse5) a division of the cleft foot of an animal6) SYNAPTIC CLEFT
* * *(kleft) 1. a fissure or elongated opening, especially one occurring in the embryo. 2. a pathologic fissure derived from a failure of parts to fuse during embryonic development.
Medical dictionary. 2011.