| Fossa for lacrimal gland | |
|---|---|
 Frontal bone. Inferior view. The location of the Lacrimal fossa for the Lacrimal gland | |
| Details | |
| Identifiers | |
| Latin | fossa glandulae lacrimalis |
| TA | A02.1.03.026 |
| FMA | 57396 |
| Anatomical terms of bone | |
The lacrimal fossa (or fossa for lacrimal gland) is located on the inferior surface of each orbital plate of the frontal bone. It is smooth and concave, and presents, laterally, underneath the zygomatic process, a shallow depression for the lacrimal gland.
The lacrimal bone is a small and fragile bone of the facial skeleton; it is roughly the size of the little fingernail. It is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders. Several bony landmarks of the lacrimal bone function in the process of lacrimation or crying. Specifically, the lacrimal bone helps form the nasolacrimal canal necessary for tear translocation. A depression on the anterior inferior portion of the bone, the lacrimal fossa, houses the membranous lacrimal sac. Tears or lacrimal fluid, from the lacrimal glands, collect in this sac during excessive lacrimation. The fluid then flows through the nasolacrimal duct and into the nasopharynx. This drainage results in what is commonly referred to a runny nose during excessive crying or tear production. Injury or fracture of the lacrimal bone can result in posttraumatic obstruction of the lacrimal pathways.
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. Anatomical term created by Gerard of Cremona. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is 30 millilitres, of which the eye occupies 6.5 ml. The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and nasolacrimal duct, the eyelids, medial and lateral palpebral ligaments, check ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves.
In human physiology, the lacrimal glands are paired, almond-shaped exocrine glands, one for each eye, that secrete the aqueous layer of the tear film. They are situated in the upper lateral region of each orbit, in the lacrimal fossa of the orbit formed by the frontal bone. Inflammation of the lacrimal glands is called dacryoadenitis. The lacrimal gland produces tears which then flow into canals that connect to the lacrimal sac. From that sac, the tears drain through the lacrimal duct into the nose.
The pterygopalatine ganglion is a parasympathetic ganglion found in the pterygopalatine fossa. It is largely innervated by the greater petrosal nerve ; and its axons project to the lacrimal glands and nasal mucosa. The flow of blood to the nasal mucosa, in particular the venous plexus of the conchae, is regulated by the pterygopalatine ganglion and heats or cools the air in the nose. It is one of four parasympathetic ganglia of the head and neck, the others being the submandibular ganglion, otic ganglion, and ciliary ganglion.
The orbital or horizontal part of the frontal bone consists of two thin triangular plates, the orbital plates, which form the vaults of the orbits, and are separated from one another by a median gap, the ethmoidal notch.
The greater petrosal nerve is a nerve in the skull that branches from the facial nerve; it forms part of a chain of nerves that innervate the lacrimal gland. The preganglionic parasympathetic axons of this nerve synapse in the pterygopalatine ganglion.
The ophthalmic nerve (V1) is one of three divisions of the trigeminal nerve (CN V). It has three branches that provide sensory innervation to the eye, skin of the upper face and anterior scalp.
The zygomatic nerve is a branch of the maxillary nerve, itself a branch of the trigeminal nerve. It travels through the orbit and divides into branches that provide sensory innervation to skin over the zygomatic and temporal bones.
The middle cranial fossa, deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior fossa by the clivus and the petrous crest.
The lacrimal artery is an artery that arises close to the optic foramen, and is one of the largest branches derived from the ophthalmic artery. Not infrequently it is given off before the artery enters the orbit.
The lacrimal apparatus is the physiological system containing the orbital structures for tear production and drainage.
It consists of:
The lacrimal sac or lachrymal 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 connects the lacrimal canaliculi, which drain tears from the eye's surface, and the nasolacrimal duct, which conveys this fluid into the nasal cavity. Lacrimal sac occlusion leads to dacryocystitis.
The nerve of the pterygoid canal is formed by the junction of the greater petrosal nerve and deep petrosal nerve, which passes from the foramen lacerum to the pterygopalatine fossa through the pterygoid canal.
The lateral or orbital surface of the lacrimal bone is divided by a vertical ridge, the posterior lacrimal crest, into two parts.
The anterior lacrimal crest is a bony projection on the frontal process of maxilla in the skull. It creates the lateral margin of the lacrimal sac fossa and is continuous with the orbital margin. At its junction with the orbital surface is a small tubercle, the lacrimal tubercle, which serves as a guide to the position of the lacrimal sac. The medial palpebral ligament is attached to anterior lacrimal crest.
The following outline is provided as an overview of and topical guide to human anatomy:
Johann Christian Rosenmüller was a German anatomist born near Hildburghausen, Thuringia. He was the son of theologian Johann Georg Rosenmüller (1736-1815).
In anatomy, a fossa is a depression or hollow, usually in a bone, such as the hypophyseal fossa. Some examples include:
Lacrimal fossa can refer to:
A smooth, more deeply concave depression on the lacrimal bone, which forms the medial wall of the orbital cavity, in which the lacrimal sac that drains into the nasolacrimal duct is located, is referred to as the lacrimal fossa.
This article incorporates text in the public domain from page 137 of the 20th edition of Gray's Anatomy (1918)
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