- An opening, as in the diaphragm. When there is an unusually wide opening in the diaphragm, there can be a hiatus (or hiatal) hernia. In Latin an hiatus is "an opening, gaping mouth, or chasm." It is derived from the verb "hiare" meaning "to gape or yawn." Therefore, a "hiatus" is a gaping opening in anything, such as the opening in a cliff leading into a cave or a break in the conversation in which nothing happens or is said.
* * *- adductor h. [TA] the aperture in the aponeurotic insertion of the adductor magnus that transmits the femoral artery and vein from the adductor canal to the popliteal space. SYN: h. adductorius [TA], femoral opening, h. tendineus, tendinous opening.- h. adductorius [TA] SYN: adductor h..- aortic h. [TA] the opening in the diaphragm bounded by the two crura, the vertebral column, and the median arcuate ligament, through which pass the aorta and thoracic duct. SYN: h. aorticus [TA], aortic foramen, aortic opening.- h. aorticus [TA] SYN: aortic h..- Breschet h. SYN: helicotrema.- esophageal h. [TA] the opening in the right crus of the diaphragm, between the central tendon and the h. aorticus, through which pass the esophagus and the two vagus nerves. SYN: h. esophageus [TA], esophageal opening.- h. esophageus [TA] SYN: esophageal h..- h. ethmoidalis SYN: semilunar h..- h. for greater petrosal nerve [TA] the opening on the anterior aspect of the petrous part of the temporal bone that leads to the facial canal and gives passage to the greater petrosal nerve. SYN: h. canalis nervi petrosi majoris [TA], fallopian h., Ferrein foramen, h. canalis facialis, h. of facial canal.- h. for lesser petrosal nerve [TA] the small opening in the petrous bone lateral to the h. for greater petrosal nerve that gives passage to the lesser petrosal nerve. SYN: h. canalis nervi petrosi minoris [TA], Arnold canal, canalis nervi petrosi superficialis minoris.- h. maxillaris [TA] SYN: maxillary h..- maxillary h. [TA] the large opening into the maxillary sinus on the nasal surface of the maxilla. SYN: h. maxillaris [TA].- pleuropericardial h. an opening connecting the pleural and pericardial cavities; usually the result of incomplete development of the pleuropericardial fold of the embryo.- pleuroperitoneal h. an opening through the diaphragm, connecting pleural and peritoneal cavities, usually the result of defective development of the pleuroperitoneal membrane in the embryo; if the defect is extensive there may be herniation of digestive organs into the pleural cavity. SEE ALSO: diaphragmatic hernia. SYN: Bochdalek foramen.- sacral h. [TA] a normally occurring gap at the lower end of the sacrum, exposing the vertebral canal, due to failure of the laminae of the last sacral segment to coalesce. It is closed by the sacrococcygeal ligament, and provides cannular access to the sacral epidural space for administration of anesthetics (caudal nerve blocks). SYN: h. sacralis [TA].- h. sacralis [TA] SYN: sacral h..- h. saphenus [TA] SYN: saphenous opening.- scalene h. triangular gap bounded by the scalenus anterior and scalenus medius muscles and the first rib to which the muscles attach; the h. provides passage for the subclavian artery and the roots of the brachial plexus. Compression of the structures passing through the h. by any means is manifest as “thoracic outlet syndrome.” SYN: interscalene triangle.- semilunar h. [TA] a deep, narrow groove in the lateral wall of the middle meatus of the nasal cavity, into which the maxillary sinus, the frontonasal duct, and the middle ethmoid cells open. SYN: h. semilunaris [TA], h. ethmoidalis.- h. semilunaris [TA] SYN: semilunar h..- h. subarcuatus SYN: subarcuate fossa.- h. tendineus SYN: adductor h..- h. totalis sacralis developmental clefting in all sacral vertebrae; may also involve adjacent lumbar vertebrae.
* * *hi·a·tus hī-'āt-əs n a gap or passage through an anatomical part or organ esp a gap through which another part or organ passes
* * *n.an opening or aperture. For example, the diaphragm contains hiatuses for the oesophagus and aorta.
* * *hi·a·tus (hi-aґtəs) gen. and pl. hiaґtus [L.] a gap, cleft, or opening. hiatal adj
Medical dictionary. 2011.