| descending part of facial canal | Second portion of the facial canal, after the horizontal parts, beginning at the posterior end of the lateral crus where the canal begins to descend. It runs vertically downward, ending at the stylomastoid foramen. Anteriorly, the descending part of the facial canal communicates with the tympanic cavity via the canaliculus for the nerve to the stapedius muscle and the posterior canaliculus of the chorda tympani. (05 Mar 2000) |
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| Dorello's canal | A bony canal sometimes found at the tip of the temporal bone enclosing the abducens nerve and inferior petrosal sinus as these two structures enter the cavernous sinus. (05 Mar 2000) |
| Dupuytren's canal | <anatomy, vein> One of the veins in the diploe of the cranial bones, connected with the cerebral sinuses by emissary veins; the main diploic veins are the frontal, anterior temporal, posterior temporal, and occipital. Synonym: vena diploica, Breschet's vein, Dupuytren's canal. (05 Mar 2000) |
| incisive canal cyst | A cyst in or near the incisive canal, arising from proliferation of epithelial remnants of the nasopalatine duct; the most common maxillary development cyst. Synonym: median anterior maxillary cyst, nasopalatine duct cyst. (05 Mar 2000) |
| incisor canal | One of several bony canals leading from the floor of the nasal cavity into the incisive fossa on the palatal surface of the maxilla; they convey the nasopalatine nerves and branches of the greater palatine arteries which anastomose with the septal branch of the sphenopalatine artery. Synonym: canalis incisivus. (05 Mar 2000) |
| inferior dental canal | The canal within the mandible that transmits the inferior alveolar nerve and vessels. Its posterior opening is the mandibular foramen. Synonym: canalis mandibulae, inferior dental canal. (05 Mar 2000) |
| infraorbital canal | A canal running beneath the orbital margin of the maxilla from the infraorbital groove, in the floor of the orbit, to the infraorbital foramen; it transmits the infraorbital artery and nerve. Synonym: canalis infraorbitalis. (05 Mar 2000) |
| inguinal canal | A passage in the lower anterior abdominal wall which in the male allows passage of the spermatic cord and in the female contains the round ligament. Because of the weakness it creates in the abdominal wall, it is the most frequent site for a hernia. (12 Dec 1998) |
| internal auditory canal | <anatomy> Abnormal if difference in diameter greater than 2 mm, schematic: 7 8-sv anterior posterior 8-c 8-iv, 7 facial nerve (VII), 8-c cochlear division of VIII, 8-sv superior vestibular division, 8-iv inferior vestibular division (12 Dec 1998) |
| introitus of facial canal | Entrance to facial canal, through which the facial nerve passes, at end of internal acoustic meatus. Synonym: introitus canalis. (05 Mar 2000) |
| obturator canal | The opening in the superior part of the obturator membrane through which the obturator nerve and vessels pass from the pelvic cavity into the thigh. Synonym: canalis obturatorius. (05 Mar 2000) |
| optic canal | The short canal through the lesser wing of the sphenoid bone at the apex of the orbit that gives passage to the optic nerve and the ophthalmic artery. Synonym: canalis opticus, foramen opticum, optic foramen. (05 Mar 2000) |
| tarsal canal | tarsal sinus |
| temporal canal | <anatomy> A canal in the zygomatic bone transmitting the zygomaticofacial and zygomaticotemporal nerves and vessels. (05 Mar 2000) |
| Theile's canal | transverse pericardial sinus |