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Information about Lacrimal Bone

Bone:
Lacrimal bone visible near center.
Orbital bones
Latinos lacrimale
subject #39 164
The lacrimal bone, the smallest and most fragile bone of the face, is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders.

Surfaces

Lateral or orbital surface

The lateral or orbital surface is divided by a vertical ridge, the posterior lacrimal crest, into two parts.

In front of this crest is a longitudinal groove, the lacrimal sulcus (sulcus lacrimalis), the inner margin of which unites with the frontal process of the maxilla, and the lacrimal fossa is thus completed. The upper part of this fossa lodges the lacrimal sac, the lower part, the nasolacrimal duct.

The portion behind the crest is smooth, and forms part of the medial wall of the orbit.

The crest, with a part of the orbital surface immediately behind it, gives origin to the lacrimal part of the Orbicularis oculi and ends below in a small, hook-like projection, the lacrimal hamulus, which articulates with the lacrimal tubercle of the maxilla, and completes the upper orifice of the nasolacrimal canal; the hamulus sometimes exists as a separate piece, and is then called the lesser lacrimal bone.

Medial or nasal surface

The medial or nasal surface presents a longitudinal furrow, corresponding to the crest on the lateral surface.

The area in front of this furrow forms part of the middle meatus of the nose; that behind it articulates with the ethmoid, and completes some of the anterior ethmoidal cells.

Borders

Of the four borders:
  • the anterior articulates with the frontal process of the maxilla;
  • the posterior with the lamina papyracea of the ethmoid;
  • the superior with the frontal bone.
  • The inferior is divided by the lower edge of the posterior lacrimal crest into two parts:
  • the posterior part articulates with the orbital plate of the maxilla;
  • the anterior is prolonged downward as the descending process, which articulates with the lacrimal process of the inferior nasal concha, and assists in forming the canal for the nasolacrimal duct.

Ossification

The lacrimal is ossified from a single center, which appears about the twelfth week in the membrane covering the cartilaginous nasal capsule.

Articulations

The lacrimal articulates with four bones: two of the cranium, the frontal and ethmoid, and two of the face, the maxilla and the inferior nasal concha.

Additional images




Left lacrimal bone. Orbital surface. Enlarged

Side view of the skull.

The skull from the front.

Medial wall of left orbit.

Roof, floor, and lateral wall of left nasal cavity.

See also

External links

 •  • [ e]
The Bones which form the Orbit
Frontal bone • Zygomatic bone • Maxillary bone • Sphenoid bone • Ethmoid bone • Palatine bone • Lacrimal bone
 •  • [ e]
Bones of head and neck: the face
maxillaBody of maxilla - Maxillary sinus - surfaces of body Anterior (Incisive fossa, Canine fossa, Infraorbital foramen, Anterior nasal spine) - Infratemporal (Alveolar canals, Maxillary tuberosity) - Orbital (Infraorbital groove, Infraorbital canal) - Nasal (Pterygopalatine canal) - processes Zygomatic process - Frontal process (Agger nasi, Anterior lacrimal crest) - Alveolar process - Palatine process (Incisive foramen, Incisive canals, Foramina of Scarpa, Premaxilla, Anterior nasal spine)
lacrimalPosterior lacrimal crest - Lacrimal groove
zygomaticOrbital process, Zygomaticofacial foramen - Zygomaticotemporal foramen - Zygomaticorbital foramina
palatinePterygopalatine fossa - Pterygoid fossa - Horizontal plate (Posterior nasal spine) - Perpendicular plate (Pterygopalatine canal, Sphenopalatine foramen, Pyramidal process)
processes (Orbital - Sphenoidal)
mandiblebody (Symphysis menti, Mental protuberance, Mental foramen, Mylohyoid line) - Ramus (Mandibular foramen, Mylohyoid groove, Mandibular canal, Angle, Coronoid process, Condyloid process, Mandibular notch)
othersnasal bone - inferior nasal conchae (ethmoidal process, maxillary process) - vomer
Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Bones are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals.
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In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated.

It can also mean the skin which surrounds the eye of a bird.

In the adult human, the volume of the orbit is 30 ml, of which the eye occupies 6.5 ml.
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The lateral or orbital surface of the lacrimal bone is divided by a vertical ridge, the posterior lacrimal crest, into two parts.

In front of this crest is a longitudinal groove, the lacrimal sulcus (sulcus lacrimalis), the inner margin of which unites with the frontal
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lacrimal groove (or lacrimal sulcus), which is converted into the nasolacrimal canal, by the lacrimal bone and inferior nasal concha; this canal opens into the inferior meatus of the nose and transmits the nasolacrimal duct.
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The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible, which is also a fusion of two halves at the mental symphysis.
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Fossa is the Latin word for ditch or trench. More specifically, it can refer to one of the following:

Anatomy

In anatomical terminology, fossa has come to mean a depression or hollow, typically in a bone.
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The lacrimal sac, is the upper dilated end of the nasolacrimal duct, and is lodged in a deep groove formed by the lacrimal bone and frontal process of the maxilla.

It is oval in form and measures from 12 to 15 mm.
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The nasolacrimal duct carries tears from the lacrimal sac into the nasal cavity. Excess tears flow through nasolacrimal duct which opens in the nose. This is the reason the nose starts to run when a person is crying, or why you can sometimes taste eye drops.
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The orbicularis oculi is a muscle in the face that closes the eyelids. It arises from the nasal part of the frontal bone, from the frontal process of the maxilla in front of the lacrimal groove, and from the anterior surface and borders of a short fibrous band, the medial
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lacrimal tubercle, which serves as a guide to the position of the lacrimal sac.

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated.
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The canal containing the nasolacrimal duct is called the nasolacrimal canal.

It is formed by indentations in the inferior nasal conchae, maxilla and lacrimal bone.

See also

  • Orbit (anatomy)

Additional images


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In anatomy, a meatus is a natural body opening or canal (pl. meatus, or meatuses).

Examples include:
  • the auditory meatus, the opening of the ear canal
  • the urinary meatus, which is the opening of the urethra, situated on the glans penis in males, and in the vulva

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The ethmoid bone (from Greek ethmos, "sieve") is a bone in the skull that separates the nasal cavity from the brain. As such, it is located at the roof of the nose, between the two orbits. The cubical bone is lightweight due to a spongy construction.
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The ethmoid sinus, one of the paranasal sinuses, is the collective name for the ethmoidal air cells.

Each ethmoid sinus is an air-space enclosed within the ethmoid bone.
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lamina papyracea (or orbital lamina), which covers in the middle and posterior ethmoidal cells and forms a large part of the medial wall of the orbit.

It articulates above with the orbital plate of the frontal bone, below with the maxilla and the orbital process of
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The inferior nasal concha (Inferior Turbinated Bone) is one of the turbinates in the nose. It extends horizontally along the lateral wall of the nasal cavity [Fig. 1] and consists of a lamina of spongy bone, curled upon itself like a scroll.
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The frontal bone is a bone in the human skull that resembles a cockleshell in form, and consists of two portions:
  • a vertical portion, the squama frontalis, corresponding with the region of the forehead.

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The ethmoid bone (from Greek ethmos, "sieve") is a bone in the skull that separates the nasal cavity from the brain. As such, it is located at the roof of the nose, between the two orbits. The cubical bone is lightweight due to a spongy construction.
..... Click the link for more information.
The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible, which is also a fusion of two halves at the mental symphysis.
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In sciences dealing with the anatomy of animals, precise anatomical terms of location are necessary for a variety of reasons. Non-scientists often wonder why zoological and human anatomists use complex terminology to describe locations on a body, when common terms like "up",
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eMedicine is an online clinical medical knowledge base that was founded in 1996 by Scott Plantz and Richard Lavely, two medical doctors. It was sold to WebMD in January 2006.
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University of Michigan, Ann Arbor (U of M, UM or simply Michigan) is a coeducational public research university in the state of Michigan. The university was founded in 1817 in Detroit, about 20 years before the territory of Michigan officially became a state,
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University of Michigan, Ann Arbor (U of M, UM or simply Michigan) is a coeducational public research university in the state of Michigan. The university was founded in 1817 in Detroit, about 20 years before the territory of Michigan officially became a state,
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Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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The frontal bone is a bone in the human skull that resembles a cockleshell in form, and consists of two portions:
  • a vertical portion, the squama frontalis, corresponding with the region of the forehead.

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The zygomatic bone (malar bone) is a paired bone of the human skull. It articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. It forms part of the orbit and is commonly referred to as the cheekbone.
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The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible, which is also a fusion of two halves at the mental symphysis.
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The sphenoid bone (from Greek sphenoeides, "wedgelike") is a bone situated at the base of the skull in front of the temporals and basilar part of the occipital bone.

The sphenoid bone somewhat resembles a butterfly or bat with its wings extended.
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The ethmoid bone (from Greek ethmos, "sieve") is a bone in the skull that separates the nasal cavity from the brain. As such, it is located at the roof of the nose, between the two orbits. The cubical bone is lightweight due to a spongy construction.
..... Click the link for more information.


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