| 释义 |
lacrimal bone
lac′rimal bone`
n. a skull bone extending from each orbit to the nasal region, greatly reduced in mammals. [1850–55] Thesaurus| Noun | 1. | lacrimal bone - small fragile bone making up part of the front inner walls of each eye socket and providing room for the passage of the lacrimal ductsbone, os - rigid connective tissue that makes up the skeleton of vertebratescranial orbit, eye socket, orbital cavity, orbit - the bony cavity in the skull containing the eyeball |
lacrimal bone
lacrimal bone[′lak·rə·məl ‚bōn] (anatomy) A small bone located in the anterior medial wall of the orbit, articulating with the frontal, ethmoid, maxilla, and inferior nasal concha. lacrimal bone
lac·ri·mal bone [TA] an irregularly rectangular thin plate, forming part of the medial wall of the orbit posterior to the frontal process of the maxilla; it articulates with the inferior nasal concha, ethmoid, frontal, and maxillary bones. Synonym(s): os lacrimale [TA], os unguislacrimal bonen. A thin irregularly rectangular plate forming part of the medial wall of the eye socket behind the frontal process of the maxilla.lac·ri·mal bone (lak'ri-măl bōn) [TA] An irregularly rectangular thin plate, forming part of the medial wall of the orbit behind the frontal process of the maxilla; it articulates with the inferior nasal concha, ethmoid, frontal, and maxillary bones. lacrimal bone A small plate of bone, situated just inside the inner wall of the eye socket (orbit), with a shallow hollow to accommodate the LACRIMAL SAC.orbit A rigid bony cavity in the skull which contains an eyeball, orbital fat, the extraocular muscles, the optic nerve, nerves and blood vessels, lacrimal system and fibrous tissue of various kinds. This packing serves to keep the eyeball reasonably well fixed in place as it rotates. The orbital cavity has the approximate form of a pyramid. The walls of the orbital cavity are formed by seven bones. The medial wall of the orbit consists of: (1) the frontal process of the maxilla (maxillary); (2) the lacrimal bone; (3) the lamina papyracea of the ethmoid; and (4) a small part of the body of the sphenoid. The floor of the orbit consists of: (1) the orbital plate of the maxilla; (2) the orbital surface of the zygomatic (malar) bone and (3) the orbital process of the palatine bone. The lateral wall of the orbit consists of (1) the orbital surface of the greater wing of the sphenoid, and (2) the orbital surface of the zygomatic. The roof of the orbit is made up mainly by the frontal bone and behind this by the lesser wing of the sphenoid. The orbit is lined with a membrane of tissue called the periorbita (or orbital periosteum) which extends to the orbital margin (anterior rim of the orbit) where it becomes continuous with the periosteum covering the facial bones. The periorbita is loosely attached to the bones except at sutures, foramina and the orbital margin where it is firmly attached. The bones are much thicker at the margin (rim) than they are along the walls of the orbital cavity. There are many apertures and gaps in the orbit through which blood vessels and nerves pass (see Table O4). See orbital axis; optic canal; inferior orbital fissure; superior orbital fissure; orbital fracture; cavernous haemangioma; lamina papyracea.
| Table O3 Bones forming the walls of the orbit | | roof | medial wall | | 1. frontal | 1. maxilla | | 2. lesser wing of sphenoid | 2. lacrimal | | 3. ethmoid | | 4. sphenoid | | floor | lateral wall | | 1. maxilla | 1. greater wing of sphenoid | | 2. zygomatic | | | 3. palatine | 2. zygomatic |
| Table O4 Orbital apertures | | aperture | location | contents | | optic canal | at the apex (in lesser sphenoid) | optic nerve
ophthalmic artery
sympathetic nerve fibres | | superior orbital fissure | at the apex (gap between greater and lesser sphenoid) | III, IV, V, VI nerves
sympathetic nerve fibres
ophthalmic vein
recurrent lacrimal artery | | inferior orbital fissure | between lateral wall and posterior part of the floor | infraorbital nerve
zygomatic nerve
branch of inferior ophthalmic vein
nerve fibres from the
pterygopalatine (sphenopalatine)
ganglion to orbital periosteum | | ethmoidal foramina (anterior and post.) | medial wall (frontal/ethmoidal suture) | ethmoidal vessels
ethmoidal nerve/external nasal nerve | | zygomatic foramen | lateral wall | zygomatic nerve and vessels | | nasolacrimal canal | medial wall (maxilla/lacrimal) | nasolacrimal duct |
lac·ri·mal bone (lak'ri-măl bōn) [TA] An irregularly rectangular thin plate, forming part of the medial wall of the orbit behind the frontal process of the maxilla; it articulates with the inferior nasal concha, ethmoid, frontal, and maxillary bones. lacrimal bone
Related to lacrimal bone: Vomer boneWords related to lacrimal bonenoun small fragile bone making up part of the front inner walls of each eye socket and providing room for the passage of the lacrimal ductsRelated Words- bone
- os
- cranial orbit
- eye socket
- orbital cavity
- orbit
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