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Lacrimal Gland
The lacrimal glands are paired exocrine glands, one for each eye, found in most terrestrial vertebrates and some marine mammals, that secrete the aqueous layer of the tear film. In humans, 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 are secreted by the lacrimal ducts, and flow over the ocular surface, and then into canals that connect to the lacrimal sac. From that sac, the tears drain through the lacrimal duct into the nose. Anatomists divide the gland into two sections, a palpebral lobe, or portion, and an orbital lobe or portion. The smaller ''palpebral lobe'' lies close to the eye, along the inner surface of the eyelid; if the upper eyelid is everted, the palpebral portion can be seen. The orbital lobe of the gland, contains fine interlobular ducts that connect the orbital lobe and the palpebr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Apparatus
The lacrimal apparatus is the physiological system containing the orbital structures for tear production and drainage.Cassin, B. and Solomon, S. ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company, 1990. It consists of: * The lacrimal gland, which secretes the tears, and its excretory ducts, which convey the fluid to the surface of the human eye; it is a j-shaped serous gland located in lacrimal fossa. * The lacrimal canaliculi, the lacrimal sac, and the nasolacrimal duct, by which the fluid is conveyed into the cavity of the nose, emptying anterioinferiorly to the inferior nasal conchae from the nasolacrimal duct; * The innervation of the lacrimal apparatus involves both the a sympathetic supply through the carotid plexus of nerves around the internal carotid artery, and parasympathetically from the lacrimal nucleus of the facial nerve. The blood supply to the lacrimal gland is provided by the ophthalmic artery with its branch - the lacrimal a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encyclopædia Britannica 2010 Ultimate Reference Suite DVD
An encyclopedia (American English) or encyclopædia (British English) is a reference work or compendium providing summaries of knowledge either general or special to a particular field or discipline. Encyclopedias are divided into articles or entries that are arranged alphabetically by article name or by thematic categories, or else are hyperlinked and searchable. Encyclopedia entries are longer and more detailed than those in most dictionaries. Generally speaking, encyclopedia articles focus on ''factual information'' concerning the subject named in the article's title; this is unlike dictionary entries, which focus on linguistic information about words, such as their etymology, meaning, pronunciation, use, and grammatical forms.Béjoint, Henri (2000)''Modern Lexicography'', pp. 30–31. Oxford University Press. Encyclopedias have existed for around 2,000 years and have evolved considerably during that time as regards language (written in a major international or a vernac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterygopalatine Ganglion
The pterygopalatine ganglion (aka Meckel's ganglion, nasal ganglion, or sphenopalatine ganglion) is a parasympathetic ganglion found in the pterygopalatine fossa. It is largely innervated by the greater petrosal nerve (a branch of the facial nerve); and its postsinaptic 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. Structure The pterygopalatine ganglion (of Meckel), the largest of the parasympathetic ganglia associated with the branches of the maxillary nerve, is deeply placed in the pterygopalatine fossa, close to the sphenopalatine foramen. It is triangular or heart-shaped, of a reddish-gray color, and is situated just below the maxillary nerve as it c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygomatic Nerve
The zygomatic nerve is a branch of the maxillary nerve, itself a branch of the trigeminal nerve (CN V). It travels through the orbit and divides into the zygomaticotemporal and the zygomaticofacial nerve. It provides sensory supply to skin over the zygomatic bone and the temporal bone. It also carries postganglionic parasympathetic axons to the lacrimal gland. It may be blocked by anaesthetising the maxillary nerve. Structure The zygomatic nerve is a branch of the maxillary nerve (CN V2), itself a branch of the trigeminal nerve (CN V). It branches at the pterygopalatine ganglion. It travels from the pterygopalatine fossa through the inferior orbital fissure to enter the orbit. In the orbit, it travels anteriorly along the lateral wall. Branches Soon after the zygomatic nerve enters the orbit it divides into its branches. These include: * the zygomaticotemporal nerve. This passes through the zygomaticotemporal foramen in the zygomatic bone. * the zygomaticofacial nerve. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigeminal Nerve
In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewing; it is the most complex of the cranial nerves. Its name ("trigeminal", ) derives from each of the two nerves (one on each side of the pons) having three major branches: the ophthalmic nerve (V), the maxillary nerve (V), and the mandibular nerve (V). The ophthalmic and maxillary nerves are purely sensory, whereas the mandibular nerve supplies motor as well as sensory (or " cutaneous") functions. Adding to the complexity of this nerve is that autonomic nerve fibers as well as special sensory fibers ( taste) are contained within it. The motor division of the trigeminal nerve derives from the basal plate of the embryonic pons, and the sensory division originates in the cranial neural crest. Sensory information from the face and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmic Nerve
The ophthalmic nerve (V1) is a sensory nerve of the face. It is one of three divisions of the trigeminal nerve (CN V). It has three branches that provide sensory innervation to the eye, the skin of the upper face, and the skin of the anterior scalp. Structure The ophthalmic nerve is the first branch of the trigeminal nerve (CN V). It is joined by filaments from the cavernous plexus of the sympathetic, and communicates with the oculomotor, trochlear, and abducent nerves. It gives off a recurrent (meningeal) filament which passes between the layers of the tentorium. Branches The ophthalmic nerve divides into three major branches as it passes through the superior orbital fissure. *The nasociliary nerve gives off several sensory branches to the orbit. It then continues out through the anterior ethmoidal foramen, where it enters the nasal cavity. It provides innervation for much of the anterior nasal mucosa. It also gives off a branch which exits through the nasal bones to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmic Artery
The ophthalmic artery (OA) is an artery of the head. It is the first branch of the internal carotid artery distal to the cavernous sinus. Branches of the ophthalmic artery supply all the structures in the orbit around the eye, as well as some structures in the nose, face, and meninges. Occlusion of the ophthalmic artery or its branches can produce sight-threatening conditions. Structure The ophthalmic artery emerges from the internal carotid artery. This is usually just after the internal carotid artery emerges from the cavernous sinus. In some cases, the ophthalmic artery branches just before the internal carotid exits the cavernous sinus. The ophthalmic artery emerges along the medial side of the anterior clinoid process. It runs anteriorly, passing through the optic canal inferolaterally to the optic nerve. It can also pass superiorly to the optic nerve in a minority of cases. In the posterior third of the cone of the orbit, the ophthalmic artery turns sharply and mediall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Striated Ducts
In anatomy and physiology, a duct is a circumscribed channel leading from an exocrine gland or organ. Types of ducts Examples include: Duct system As ducts travel from the acinus which generates the fluid to the target, the ducts become larger and the epithelium becomes thicker. The parts of the system are classified as follows: Some sources consider "lobar" ducts to be the same as "interlobar ducts", while others consider lobar ducts to be larger and more distal from the acinus. For sources that make the distinction, the interlobar ducts are more likely to classified with simple columnar epithelium (or pseudostratified epithelium), reserving the stratified columnar for the lobar ducts. File:Gray1025.png, Section of submaxillary gland of kitten. Duct semidiagrammatic. X 200. File:Gray1173.png, Section of portion of mamma. Intercalated duct The intercalated duct, also called intercalary duct (ducts of Boll), is the portion of an exocrine gland leading directly from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intralobular Ducts
In anatomy and physiology, a duct is a circumscribed channel leading from an exocrine gland or organ. Types of ducts Examples include: Duct system As ducts travel from the acinus which generates the fluid to the target, the ducts become larger and the epithelium becomes thicker. The parts of the system are classified as follows: Some sources consider "lobar" ducts to be the same as "interlobar ducts", while others consider lobar ducts to be larger and more distal from the acinus. For sources that make the distinction, the interlobar ducts are more likely to classified with simple columnar epithelium (or pseudostratified epithelium), reserving the stratified columnar for the lobar ducts. File:Gray1025.png, Section of submaxillary gland of kitten. Duct semidiagrammatic. X 200. File:Gray1173.png, Section of portion of mamma. Intercalated duct The intercalated duct, also called intercalary duct (ducts of Boll), is the portion of an exocrine gland leading directly from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumen (anatomy)
In biology, a lumen (plural lumina) is the inside space of a tubular structure, such as an artery or intestine. It comes . It can refer to: *The interior of a vessel, such as the central space in an artery, vein or capillary through which blood flows. *The interior of the gastrointestinal tract *The pathways of the bronchi in the lungs *The interior of renal tubules and urinary collecting ducts *The pathways of the female genital tract, starting with a single pathway of the vagina, splitting up in two lumina in the uterus, both of which continue through the Fallopian tubes In cell biology, a lumen is a membrane-defined space that is found inside several organelles, cellular components, or structures: * thylakoid, endoplasmic reticulum, Golgi apparatus, lysosome, mitochondrion, or microtubule Transluminal procedures ''Transluminal procedures'' are procedures occurring through lumina, including: * Natural orifice transluminal endoscopic surgery in the lumina of, for exa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acinus
An acinus (; plural, acini; adjective, acinar or acinous) refers to any cluster of cells that resembles a many-lobed "berry," such as a raspberry (''acinus'' is Latin for "berry"). The berry-shaped termination of an exocrine gland, where the secretion is produced, is acinar in form, as is the alveolar sac containing multiple alveoli in the lungs. Exocrine glands Acinar exocrine glands are found in many organs, including: * the stomach * the sebaceous gland of the scalp * the salivary glands of the tongue * the liver * the lacrimal glands * the mammary glands * the pancreas * the bulbourethral (Cowper's) glands The thyroid follicles can also be considered of acinar formation but in this case the follicles, being part of an ''endocrine'' gland, act as a hormonal deposit rather than to facilitate secretion. Mucous acini usually stain pale, while serous acini usually stain dark. Lungs The end of the terminal bronchioles in the lungs mark the beginning of a pulmonary a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connective Tissue
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord are composed of connective tissue. Most types of connective tissue consists of three main components: elastic and collagen fibers, ground substance, and cells. Blood, and lymph are classed as specialized fluid connective tissues that do not contain fiber. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leucocytes. The term "connective tissue" (in German, ''Bindegewebe'') was introduced in 1830 by Johannes Peter Müller. The tissue was already recognized as a distinct class in the 18th century. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
