| ethmoid bone | An irregularly shaped bone lying between the orbital plates of the frontal and anterior to the sphenoid bone; it consists of two lateral masses of thin plates enclosing air cells, attached above to a perforated horizontal lamina, the cribriform plate, from which descends a median vertical or perpendicular plate in the interval between the two lateral masses; the bone articulates with the sphenoid, frontal, maxillary, lacrimal, and palatine bones, the inferior nasal concha, and the vomer; it enters into the formation of the anterior cranial fossa, the orbits, and the nasal cavity. Synonym: os ethmoidale. (05 Mar 2000) |
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| perpendicular plate of ethmoid bone | A thin plate of bone projecting downward from the crista galli of the ethmoid; it forms part of the nasal septum. Synonym: lamina perpendicularis ossis ethmoidalis. (05 Mar 2000) |
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| cribriform plate of ethmoid bone | A horizontal lamina from which are suspended the labyrinth, on either side, and the lamina perpendicularis in the centre; it fits into the ethmoidal notch of the frontal bone and supports the olfactory lobes of the cerebrum, being pierced with numerous openings for the passage of the olfactory nerves. Synonym: lamina cribrosa ossis ethmoidalis, cribrum, sieve bone, sieve plate. (05 Mar 2000) |
| orbital lamina of ethmoid bone | A thin plate of ethmoid bone forming part of the medial wall of the orbit and the lateral wall for the ethmoidal labyrinth. Synonym: lamina orbitalis ossis ethmoidalis, lamina papyracea, orbital lamina of ethmoid bone, orbital layer of ethmoid bone, orbital plate, paper plate, papyraceous plate. (05 Mar 2000) |
| orbital layer of ethmoid bone | A thin plate of ethmoid bone forming part of the medial wall of the orbit and the lateral wall for the ethmoidal labyrinth. Synonym: lamina orbitalis ossis ethmoidalis, lamina papyracea, orbital lamina of ethmoid bone, orbital layer of ethmoid bone, orbital plate, paper plate, papyraceous plate. (05 Mar 2000) |
| orbital plate of ethmoid bone | A thin plate of ethmoid bone forming part of the medial wall of the orbit and the lateral wall for the ethmoidal labyrinth. Synonym: lamina orbitalis ossis ethmoidalis, lamina papyracea, orbital lamina of ethmoid bone, orbital layer of ethmoid bone, orbital plate, paper plate, papyraceous plate. (05 Mar 2000) |
| uncinate process of ethmoid bone | A sickle-shaped process of bone on the medial wall of the ethmoidal labyrinth below the middle concha; it articulates with the ethmoidal process of the inferior concha and partly closes the orifice of the maxillary sinus. Synonym: processus uncinatus ossis ethmoidalis. (05 Mar 2000) |
| lateral mass of ethmoid bone | A mass of air cells with thin bony walls forming part of the lateral wall of the nasal cavity; the cells are arranged in three groups, anterior, middle, and posterior, and are closed laterally by the orbital plate which forms part of the wall of the orbit. Synonym: labyrinthus ethmoidalis, ectethmoid, ectoethmoid, lateral mass of ethmoid bone. (05 Mar 2000) |
| supra-ethmoid | <anatomy> Above, or on the dorsal side of, the ethmoid bone or cartilage. Source: Websters Dictionary (01 Mar 1998) |
| ethmoid | <anatomy> The ethmoid bone. Source: Websters Dictionary (01 Mar 1998) |
| ethmoid air cells | The numerous small air-filled cells of the ethmoidal labyrinth. See: anterior ethmoidal air cells, middle ethmoidal air cells, posterior ethmoidal air cells. Synonym: cellulae ethmoidales, sinus ethmoidales, ethmoidal cells. (05 Mar 2000) |
| ethmoid angle | The angle made by the plane of the cribriform plate of the ethmoid bone extended to meet the basicranial axis. (05 Mar 2000) |
| ethmoid infundibulum | A passage from the middle meatus of the nose communicating with the anterior ethmoidal cells and frontal sinus. Synonym: infundibulum ethmoidale, ethmoid infundibulum. (05 Mar 2000) |
| ethmoid sinus | Numerous small thin-walled spaces or air cells in the ethmoid bone, where they form an ethmoidal labyrinth. (12 Dec 1998) |
| ethmoid sinusitis | Inflammation of the ethmoid sinus. It may present itself as an acute (associated with viral rhinitis) or chronic (associated with allergic or hyperplastic sinusitis) condition. (12 Dec 1998) |
| bone within a bone | <radiology> STOP heavy metal, S: sickle cell disease, T: Thorotrast, O: osteopetrosis, P: Paget's disease, heavy metals, hypervitaminosis D (12 Dec 1998) |