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Hilton's White Line
The anocutaneous line, also called the Hilton white line or intersphincteric groove, is a boundary in the anal canal. Below the anocutaneous line, lymphatic drainage is to the superficial inguinal nodes. The anocutaneous line is slightly below the pectinate line and a landmark for the intermuscular border between internal and external anal sphincter muscles. The anocutaneous line represents the transition point from non-keratinized stratified squamous epithelium of the anal canal to keratinized stratified squamous epithelium of the anus and perianal skin. In live persons, the color of the line is white, hence the alternative name. It is named for John Hilton. See also *Anal canal *Dentate line *Hilton's Law Hilton's law, espoused by John Hilton in a series of medical lectures given in 1860–1862, is the observation that in the study of anatomy, the nerve supplying the muscles extending directly across and acting at a given joint not only supplies the ... References D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Canal
The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional segment of the bowel, it functions to regulate release of excrement by two muscular sphincter complexes. The anus is the aperture at the terminal portion of the anal canal. Structure In humans, the anal canal is approximately long, from the anorectal junction to the anus. It is directed downwards and backwards. It is surrounded by inner involuntary and outer voluntary sphincters which keep the lumen closed in the form of an anteroposterior slit. The canal is differentiated from the rectum by a transition along the internal surface from endodermal to skin-like ectodermal tissue. The anal canal is traditionally divided into two segments, upper and lower, separated by the pectinate line (also known as the dentate line): * upper zone (zona col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superficial Inguinal Nodes
Inguinal lymph nodes are lymph nodes in the human groin. Located in the femoral triangle of the inguinal region, they are grouped into superficial and deep lymph nodes. The superficial have three divisions: the superomedial, superolateral, and inferior superficial. Superficial inguinal lymph nodes * The superficial inguinal lymph nodes are the inguinal lymph nodes that form a chain immediately below the inguinal ligament. They lie deep to the fascia of Camper that overlies the femoral vessels at the medial aspect of the thigh. They are bounded superiorly by the inguinal ligament in the femoral triangle; laterally by the border of the sartorius muscle, and medially by the adductor longus muscle. They are divided into three groups: * inferior – inferior of the saphenous opening of the leg, receive drainage from lower legs * superolateral – on the side of the saphenous opening, receive drainage from the side buttocks and the lower abdominal wall. * superomedial – located at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectinate Line
The pectinate line (dentate line) is a line which divides the upper two-thirds and lower third of the anal canal. Developmentally, this line represents the hindgut-proctodeum A proctodeum is the back ectodermal part of an alimentary canal. It is created during embryogenesis by a folding of the outer body wall. It will form the lower part of the anal canal The anal canal is the part that connects the rectum to the ... junction. It is an important anatomical landmark in humans, and several distinctions can be made based upon the location of a structure relative to this line: Additional images File:Rectoanal jxn.JPG, Microscopic cross section of the anorectal junction. File:Anorectum-en.svg , Anatomy of the anus and rectum File:Gray1078.png, Coronal section of rectum and anal canal. References External links * () {{Authority control Digestive system Anatomic Landmarks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Anal Sphincter
The internal anal sphincter, IAS, (or sphincter ani internus) is a ring of smooth muscle that surrounds about 2.5–4.0 cm of the anal canal; its inferior border is in contact with, but quite separate from, the external anal sphincter. It is myogenic in nature and playing phasic and tonic state for relaxation and contraction. This myogenic tone is based on Ca2+/Calmodulin/MLCK/RhoA/ROCK signaling cascade pathway. Recent studies suggested, BDNF is the member of the neurotrophin family; having next target for basal IAS and NANC relaxation. It is about 5 mm thick, and is formed by an aggregation of the involuntary circular fibers of the rectum. Its lower border is about 6 mm from the orifice of the anus. Actions Its action is entirely involuntary, and it is in a state of continuous maximal contraction. It helps the Sphincter ani externus to occlude the anal aperture and aids in the expulsion of the feces. Sympathetic fibers from the superior rectal and hypogastric p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Anal Sphincter
The external anal sphincter (or sphincter ani externus ) is a flat plane of skeletal muscle fibers, elliptical in shape and intimately adherent to the skin surrounding the margin of the anus. Anatomy The external anal sphincter measures about 8 to 10 cm in length, from its anterior to its posterior extremity, and is about 2.5 cm opposite the anus, the sphincter muscle retracts on defecating. It consists of two layers: ''superficial'' and ''deep''. * The superficial layer, constitutes the main portion of the muscle, and arises from a narrow tendinous band, the anococcygeal raphe, which stretches from the tip of the coccyx to the posterior margin of the anus; it forms two flattened planes of muscular tissue, which encircle the anus and meet in front to be inserted into the central tendinous point of the perineum, joining with the superficial transverse perineal muscle, the levator ani, and the bulbospongiosus muscle also known as the bulbocavernosus. * The deeper layer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratified Squamous Epithelium
A stratified squamous epithelium consists of squamous (flattened) epithelial cells arranged in layers upon a basal membrane. Only one layer is in contact with the basement membrane; the other layers adhere to one another to maintain structural integrity. Although this epithelium is referred to as squamous, many cells within the layers may not be flattened; this is due to the convention of naming epithelia according to the cell type at the surface. In the deeper layers, the cells may be columnar or cuboidal. There are no intercellular spaces. This type of epithelium is well suited to areas in the body subject to constant abrasion, as the thickest layers can be sequentially sloughed off and replaced before the basement membrane is exposed. It forms the outermost layer of the skin and the inner lining of the mouth, esophagus and vagina. In the epidermis of skin in mammals, reptiles, and birds, the layer of keratin in the outer layer of the stratified squamous epithelial surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keratinized Epithelium
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellular matrix. Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin. There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either squamous, columnar, or cuboidal, or in layers of two or more cells deep as stratified (layered), or ''compound'', either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified due to the placement of the nuclei. This sort of tissue is called pseudostratified. All glands are made up of epithelial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anus
The anus (Latin, 'ring' or 'circle') is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, the residual semi-solid waste that remains after food digestion, which, depending on the type of animal, includes: matter which the animal cannot digest, such as bones; Summary at food material after the nutrients have been extracted, for example cellulose or lignin; ingested matter which would be toxic if it remained in the digestive tract; and dead or excess gut bacteria and other endosymbionts. Amphibians, reptiles, and birds use the same orifice (known as the cloaca) for excreting liquid and solid wastes, for copulation and egg-laying. Monotreme mammals also have a cloaca, which is thought to be a feature inherited from the earliest amniotes via the therapsids. Marsupials have a single orifice for excreting both solids and liquids and, in females, a separate vagina for reproduction. Female placental mamm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perianal Skin
The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), including the perineal body and surrounding structures. There is some variability in how the boundaries are defined. The perineal raphe is visible and pronounced to varying degrees. The perineum is an erogenous zone. The word perineum entered English from late Latin via Greek περίναιος ~ περίνεος ''perinaios, perineos'', itself from περίνεος, περίνεοι 'male genitals' and earlier περίς ''perís'' 'penis' through influence from πηρίς ''pērís'' 'scrotum'. The term was originally understood as a purely male body-part with the perineal raphe seen as a continuation of the scrotal septum since masculinization causes the development of a large anogenital distance in men, in comparison to the corresponding lack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Hilton (surgeon)
John Hilton FRCS, FRS, FZS (22 September 1805 – 14 September 1878) was a British surgeon. Born in Sible Hedingham in Essex in 1805, Hilton was educated at King Edward VI Grammar School, Chelmsford and in Boulogne (where he became fluent in French). He entered Guy's Hospital in 1824 when aged nineteen. He was appointed demonstrator of anatomy in 1828, assistant-surgeon in 1845 and surgeon in 1849. In 1859 he was appointed professor of human anatomy and surgery at the Royal College of Surgeons. As Arris and Gale professor from 1859 to 1862 he delivered a course of lectures on "Rest and Pain," which have become classics. He was also surgeon-extraordinary to Queen Victoria. In 1844 he was Hunterian Orator at the Hunterian Society and in 1853 elected their president for two years. In 1867 he was elected president of the Royal College of Surgeons, of which he had been made a member in 1827 and a fellow in 1843. He also delivered their Hunterian oration in 1867. From 1871 to 1873 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Canal
The anal canal is the part that connects the rectum to the anus, located below the level of the pelvic diaphragm. It is located within the anal triangle of the perineum, between the right and left ischioanal fossa. As the final functional segment of the bowel, it functions to regulate release of excrement by two muscular sphincter complexes. The anus is the aperture at the terminal portion of the anal canal. Structure In humans, the anal canal is approximately long, from the anorectal junction to the anus. It is directed downwards and backwards. It is surrounded by inner involuntary and outer voluntary sphincters which keep the lumen closed in the form of an anteroposterior slit. The canal is differentiated from the rectum by a transition along the internal surface from endodermal to skin-like ectodermal tissue. The anal canal is traditionally divided into two segments, upper and lower, separated by the pectinate line (also known as the dentate line): * upper zone (zona col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentate Line
The pectinate line (dentate line) is a line which divides the upper two-thirds and lower third of the anal canal. Developmentally, this line represents the hindgut-proctodeum A proctodeum is the back ectodermal part of an alimentary canal. It is created during embryogenesis by a folding of the outer body wall. It will form the lower part of the anal canal The anal canal is the part that connects the rectum to the ... junction. It is an important anatomical landmark in humans, and several distinctions can be made based upon the location of a structure relative to this line: Additional images File:Rectoanal jxn.JPG, Microscopic cross section of the anorectal junction. File:Anorectum-en.svg , Anatomy of the anus and rectum File:Gray1078.png, Coronal section of rectum and anal canal. References External links * () {{Authority control Digestive system Anatomic Landmarks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
