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Ischioanal Fossa
The ischioanal fossa (formerly called ischiorectal fossa) is the fat-filled wedge-shaped space located lateral to the anal canal and inferior to the pelvic diaphragm. It is somewhat prismatic in shape, with its base directed to the surface of the perineum and its apex at the line of meeting of the obturator and anal fasciae. Boundaries It has the following boundaries: - Ischiorectal fossa is colored yellow Contents The contents include: * Inside Alcock's canal, on the lateral wall ** internal pudendal artery ** internal pudendal vein ** pudendal nerve * Outside Alcock's canal, crossing the space transversely ** inferior rectal artery ** inferior rectal veins ** inferior anal nerves ** fatty tissue across which numerous fibrous bands extend from side to side allows distension of the anal canal during defecation See also * Anal triangle References Additional images File:Gray407.png, Coronal section of anterior part of pelvis, through the pubic arch. Seen from in fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perineum
The perineum (: perineums or perinea) in placentalia, placental mammals is the space between the anus and the genitals. The human perineum is between the anus and scrotum in the male or between the anus and 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. The perineal raphe is visible and pronounced to varying degrees. Etymology The word entered English from late Latin via Greek language, 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 Virilization, masculinization causes the development of a large anogenital distance in men, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphincter Ani Externus Muscle
The external anal sphincter (or sphincter ani externus) is an oval tube of Skeletal muscle#Skeletal muscle cells, skeletal muscle fibers. Distally, it is adherent to the integument, skin surrounding the margin of the anus. It exhibits a resting state of tonical contraction and also contracts during the bulbospongiosus reflex. Anatomy The external anal sphincter is far more substantial than the internal anal sphincter. The proximal portion of external anal sphincter overlaps the internal anal sphincter (which terminates distally a little distance proximal to the anal orifice) superficially; where the two overlap, they are separated by the intervening conjoint longitudinal muscle. Structure Historically, the sphincter was described as consisting of three parts (deep, superficial, and subcutaneous). This is not supported by current anatomical knowledge. Some sources still describe it in two layers, deep (or proximal) and superficial (or distal or subcutaneous). Some of the muscles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Triangle
The anal triangle is the posterior part of the perineum. It contains the anus in mammals. Structure The anal triangle can be defined either by its vertices or its sides. * ''Vertices'' ** one vertex at the coccyx bone ** the two ischial tuberosities of the pelvic bone * ''Sides'' ** perineal membrane (posterior border of perineal membrane forms anterior border of anal triangle) ** the two sacrotuberous ligaments Contents Some components of the anal triangle include:Daftary, Shirish; Chakravarti, Sudip (2011). Manual of Obstetrics, 3rd Edition. Elsevier. pp. 1-16. . * Ischioanal fossa * Anococcygeal body * Sacrotuberous ligament * Sacrospinous ligament * Pudendal nerve * Internal pudendal artery and internal pudendal vein * Anal canal * Muscles ** Sphincter ani externus muscle ** Gluteus maximus muscle ** Obturator internus muscle ** Levator ani muscle ** Coccygeus muscle Additional images Image:Gray320.png, Articulations of pelvis. Posterior view. Image:Gray5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Anal Nerves
The inferior rectal nerves (inferior anal nerves, inferior hemorrhoidal nerve) usually branch from the pudendal nerve but occasionally arises directly from the sacral plexus; they cross the ischiorectal fossa along with the inferior rectal artery and veins, toward the anal canal and the lower end of the rectum, and is distributed to the sphincter ani externus (external anal sphincter, EAS) and to the integument (skin) around the anus. Branches of this nerve communicate with the perineal branch of the posterior femoral cutaneous and with the posterior scrotal nerves at the forepart of the perineum. Supplies Cutaneous innervation below the pectinate line and external anal sphincter. See also * Inferior rectal artery Additional images File:Gray405.png, The perineum. The integument and superficial layer of superficial fascia reflected. File:Gray837.png, Sacral plexus of the right side. (Hemorrhoidal branch of pudic labeled at bottom right.) References External links Detai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Rectal Veins
The lower part of the external hemorrhoidal plexus is drained by the inferior rectal veins (or inferior hemorrhoidal veins) into the internal pudendal vein. Veins superior to the middle rectal vein in the colon and rectum drain via the portal system to the liver. Veins inferior, and including, the middle rectal vein drain into systemic circulation and are returned to the heart, bypassing the liver. Pathologies involving the Inferior rectal veins may cause lower GI bleeding. Depending on the degree of inflammation, they are given a grade level ranging from 1 through 4. Additional images File:Gray405.png, The perineum. The integument and superficial layer of superficial fascia reflected. References Veins of the torso {{circulatory-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Rectal Artery
The inferior rectal artery (inferior hemorrhoidal artery) is an artery that supplies blood to the lower third of the anal canal below the pectinate line. Structure The inferior rectal artery arises from the internal pudendal artery as it passes above the ischial tuberosity. Piercing the wall of the pudendal canal, it divides into two or three branches which cross the ischioanal fossa, and are distributed to the muscles and integument of the anal region, and send offshoots around the lower edge of the gluteus maximus to the skin of the buttock. They anastomose with the corresponding vessels of the opposite side, with the superior and middle rectal arteries, and with the perineal artery. These anastomoses can be seen during angiography performed for hemorrhoidal artery embolization. Function The inferior rectal artery supplies oxygenated blood to the anal sphincter and the lower third of the anal canal below the pectinate line. Additional images File:Gray405.png, The pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pudendal Nerve
The pudendal nerve is the main nerve of the perineum. It is a Mixed nerve, mixed (motor and sensory) nerve and also conveys Sympathetic nervous system, sympathetic Autonomic nervous system, autonomic fibers. It carries sensation from the external genitalia of both sexes and the skin around the Human anus, anus and perineum, as well as the Motor neuron, motor supply to various pelvic muscles, including the external sphincter muscle of male urethra, male or external sphincter muscle of female urethra, female external urethral sphincter and the external anal sphincter. If damaged, most commonly by childbirth, loss of sensation or fecal incontinence may result. The nerve may be temporarily anesthetized, called pudendal anesthesia or pudendal block. The pudendal canal that carries the pudendal nerve is also known by the eponymous term "Alcock's canal", after Benjamin Alcock, an Irish anatomist who documented the canal in 1836. Structure Origin The pudendal nerve is paired, me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Pudendal Vein
The internal pudendal veins (internal pudic veins) are a set of veins in the pelvis. They are the venae comitantes of the internal pudendal artery. Internal pudendal veins are enclosed by pudendal canal, with internal pudendal artery and pudendal nerve. They begin in the deep veins of the vulva and of the penis and scrotum, issuing from the bulb of the vestibule and the bulb of the penis, respectively. They accompany the internal pudendal artery, and unite to form a single vessel, which ends in the internal iliac vein. They receive the veins from the urethral bulb, the perineal and inferior hemorrhoidal veins. The deep dorsal vein of the penis Deep or The Deep may refer to: Places United States * Deep Creek (Appomattox River tributary), Virginia * Deep Creek (Great Salt Lake), Idaho and Utah * Deep Creek (Mahantango Creek tributary), Pennsylvania * Deep Creek (Mojave River tributary ... communicates with the internal pudendal veins, but ends mainly in the pudendal p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Pudendal Artery
The internal pudendal artery is one of the three pudendal arteries. It branches off the internal iliac artery, and provides blood to the external genitalia. Structure The internal pudendal artery is the terminal branch of the anterior trunk of the internal iliac artery. It is smaller in the female than in the male. Path It arises from the anterior division of internal iliac artery. It runs on the lateral pelvic wall. It exits the pelvic cavity through the greater sciatic foramen, inferior to the piriformis muscle, to enter the gluteal region. It then curves around the sacrospinous ligament to enter the perineum through the lesser sciatic foramen. It travels through the pudendal canal with the internal pudendal veins and the pudendal nerve. Branches The internal pudendal artery gives off the following branches: The deep artery of clitoris is a branch of the internal pudendal artery and supplies the clitoral crura. Another branch of the internal pudendal artery is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcock's Canal
The pudendal canal (also called Alcock's canal) is an anatomical structure formed by the obturator fascia (fascia of the obturator internus muscle) lining the lateral wall of the ischioanal fossa. The internal pudendal artery and veins, and pudendal nerve pass through the pudendal canal, and the perineal nerve arises within it. Clinical significance Pudendal nerve entrapment can occur when the pudendal nerve is compressed while it passes through the pudendal canal. History The pudendal canal is also known as Alcock's canal, named after Benjamin Alcock. Additional images Image:Gray542.png , The superficial branches of the internal pudendal artery. (Canal not labeled, but pudendal nerve and internal pudendal artery labeled at bottom right.) See also * Femoral canal * Inguinal canal * Pudendal nerve * Obturator internus muscle The internal obturator muscle or obturator internus muscle originates on the medial surface of the obturator membrane, the ischium near the membr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacrotuberous Ligament
The sacrotuberous ligament (great or posterior sacrosciatic ligament) is situated at the lower and back part of the pelvis. It is flat, and triangular in form; narrower in the middle than at the ends. Structure It runs from the sacrum (the lower transverse sacral tubercles, the inferior margins sacrum and the upper coccyx) to the tuberosity of the ischium. It is a remnant of part of biceps femoris muscle. The sacrotuberous ligament is attached by its broad base to the posterior superior iliac spine, the posterior sacroiliac ligaments (with which it is partly blended), to the lower transverse sacral tubercles and the lateral margins of the lower sacrum and upper coccyx. Its oblique fibres descend laterally, converging to form a thick, narrow band that widens again below and is attached to the medial margin of the ischial tuberosity. It then spreads along the ischial ramus as the falciform process, whose concave edge blends with the fascial sheath of the internal pudendal vessels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gluteus Maximus
The gluteus maximus is the main extensor muscle of the hip in humans. It is the largest and outermost of the three gluteal muscles and makes up a large part of the shape and appearance of each side of the hips. It is the single largest muscle in the human body. Its thick fleshy mass, in a quadrilateral shape, forms the prominence of the buttocks. The other gluteal muscles are the medius and minimus, and sometimes informally these are collectively referred to as the glutes. Its large size is one of the most characteristic features of the muscular system in humans,Norman Eizenberg et al., ''General Anatomy: Principles and Applications'' (2008), p. 17. connected as it is with the power of maintaining the trunk in the erect posture. Other primates have much flatter hips and cannot sustain standing erectly. The muscle is made up of muscle fascicles lying parallel with one another, and are collected together into larger bundles separated by fibrous septa. Structure The gluteus maxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
