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Pudendal Nerve
The pudendal nerve is the main nerve of the perineum. It carries sensation from the external genitalia of both sexes and the skin around the anus and perineum, as well as the motor supply to various pelvic muscles, including the male or female external urethral sphincter and the external anal sphincter. If damaged, most commonly by childbirth, lesions may cause sensory loss or fecal incontinence. The nerve may be temporarily blocked as part of an anaesthetic procedure. 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 The pudendal nerve is paired, meaning there are two nerves, one on the left and one on the right side of the body. Each is formed as three roots immediately converge above the upper border of the sacrotuberous ligament and the coccygeus muscle. The three roots become two cords when the middle and lower root join to fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Cutaneous Nerve Of Thigh
The posterior cutaneous nerve of the thigh (also called the posterior femoral cutaneous nerve) is a sensory nerve in the thigh. It supplies the skin of the posterior surface of the thigh, leg, buttock, and also the perineum. Structure The posterior cutaneous nerve of the thigh is a nerve from the sacral plexus. It arises partly from the dorsal divisions of the S1 and S2, and from the ventral divisions of S2 and S3 sacral spinal nerves. It leaves the pelvis through the greater sciatic foramen below the piriformis muscle. It then descends beneath the gluteus maximus muscle with the inferior gluteal artery, and runs down the back of the thigh beneath the fascia lata. It runs over the long head of the biceps femoris to the back of the knee. It then pierces the deep fascia, and accompanies the small saphenous vein to about the middle of the back of the leg. Its terminal branches communicate with the sural nerve. Branches Its branches are all cutaneous, and are distributed t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benjamin Alcock
Benjamin Alcock (1801 – 1865) was an Irish anatomist. He is remembered for his description of the pudendal nerve sheath, which came to be known as Alcock's canal, later more usually called the pudendal canal, and an associated disease, Alcock canal syndrome, also known as pudendal nerve entrapment or pudendal neuralgia. Born in Kilkenny, Ireland, he was the eldest of three sons and at least two daughters of Deborah Prim and Nathaniel Alcock (1770-1836), medical officer of the Kilkenny Dispensary. He became an accomplished anatomist working for some time under the leading Irish surgeon, Abraham Colles. After studying at Kilkenny College, he entered the University of Dublin, Trinity College in 1816, coming first in the College Entrance Examination and graduating B.A. in 1821. In 1825 Alcock became a licentiate of the Royal College of Surgeons in Ireland and obtained his M.B. degree from the University of Dublin in 1827. He became a member of the Royal College of Surgeons l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ischiorectal 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 front. File ... [...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, 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 plexus. Reference ... [...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 the dorsal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lesser Sciatic Foramen
The lesser sciatic foramen is an opening (foramen) between the pelvis and the back of the thigh. The foramen is formed by the sacrotuberous ligament which runs between the sacrum and the ischial tuberosity and the sacrospinous ligament which runs between the sacrum and the ischial spine. Structure The lesser sciatic foramen has the following boundaries: * Anterior: the tuberosity of the ischium * Superior: the spine of the ischium and sacrospinous ligament * Posterior: the sacrotuberous ligament Alternatively, the foramen can be defined by the boundaries of the lesser sciatic notch and the two ligaments. Function The following pass through the foramen: * the tendon of the Obturator internus * internal pudendal vessels * pudendal nerve * nerve to the obturator internus See also *Greater sciatic foramen The greater sciatic foramen is an opening (foramen) in the posterior human pelvis. It is formed by the sacrotuberous and sacrospinous ligaments. The piriformis muscle pass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Sciatic Foramen
The greater sciatic foramen is an opening (foramen) in the posterior human pelvis. It is formed by the sacrotuberous and sacrospinous ligaments. The piriformis muscle passes through the foramen and occupies most of its volume. The greater sciatic foramen is wider in women than in men. Structure It is bounded as follows: * anterolaterally by the greater sciatic notch of the ilium. * posteromedially by the sacrotuberous ligament. * inferiorly by the sacrospinous ligament and the ischial spine. * superiorly by the anterior sacroiliac ligament. Function The piriformis, which exits the pelvis through the foramen, occupies most of its volume. The following structures also exit the pelvis through the greater sciatic foramen: See also *Lesser sciatic foramen The lesser sciatic foramen is an opening (foramen) between the pelvis and the back of the thigh. The foramen is formed by the sacrotuberous ligament which runs between the sacrum and the ischial tuberosity and the sacrospino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coccygeus
The coccygeus muscle or ischiococcygeus is a muscle of the pelvic floor, located posterior to levator ani and anterior to the sacrospinous ligament. Structure The coccygeus muscle is posterior to levator ani and anterior to the sacrospinous ligament in the pelvic floor. It is a triangular plane of muscular and tendinous fibers. It arises by its apex from the spine of the ischium and sacrospinous ligament. It is inserted by its base into the margin of the coccyx and into the side of the lowest piece of the sacrum. In combination with the levator ani, it forms the pelvic diaphragm. The pudendal nerve runs between the coccygeus muscle and the piriformis muscle, superficial to the coccygeus muscle. Nerve supply The coccygeus muscle is innervated by the pudendal nerve, which runs between it and the piriformis muscle. Function The coccygeus muscle assists the levator ani and piriformis muscle in closing in the back part of the outlet of the pelvis. This helps to support t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piriformis Muscle
The piriformis muscle () is a flat, pyramidally-shaped muscle in the gluteal region of the lower limbs. It is one of the six muscles in the lateral rotator group. The piriformis muscle has its origin upon the front surface of the sacrum, and inserts onto the greater trochanter of the femur. Depending upon the given position of the leg, it acts either as external (lateral) rotator of the thigh or as abductor of the thigh. It is innervated by the piriformis nerve. Structure The piriformis is a flat muscle, and is pyramidal in shape. Origin The piriformis muscle originates from the anterior (front) surface of the sacrum by three fleshy digitations attached to the second, third, and fourth sacral vertebra. It also arises from the superior margin of the greater sciatic notch, the gluteal surface of the ilium (near the posterior inferior iliac spine), the sacroiliac joint capsule, and (sometimes) the sacrotuberous ligament (more specifically, the superior part of the pelvic sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacral Spinal Nerves
A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the corresponding cervical, thoracic, lumbar, sacral and coccygeal regions of the spine. There are eight pairs of cervical nerves, twelve pairs of thoracic nerves, five pairs of lumbar nerves, five pairs of sacral nerves, and one pair of coccygeal nerves. The spinal nerves are part of the peripheral nervous system. Structure Each spinal nerve is a mixed nerve, formed from the combination of nerve fibers from its dorsal and ventral roots. The dorsal root is the afferent sensory root and carries sensory information to the brain. The ventral root is the efferent motor root and carries motor information from the brain. The spinal nerve emerges from the spinal column through an opening (intervertebral foramen) between adjacent vertebrae. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventral Rami
The ventral ramus (pl. ''rami'') (Latin for ''branch'') is the anterior division of a spinal nerve. The ventral rami supply the antero-lateral parts of the trunk and the limbs. They are mainly larger than the dorsal rami. Shortly after a spinal nerve exits the intervertebral foramen, it branches into the dorsal ramus, the ventral ramus, and the ramus communicans. Each of these three structures carries both sensory and motor information. Each spinal nerve carries both sensory and motor information, via efferent and afferent nerve fibers - ultimately via the motor cortex in the frontal lobe and to somatosensory cortex in the parietal lobe - but also through the phenomenon of reflex. Spinal nerves are referred to as "mixed nerves". In the thoracic region they remain distinct from each other and each innervates a narrow strip of muscle and skin along the sides, chest, ribs, and abdominal wall. These rami are called the intercostal nerves. In regions other than the thoracic, ventral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacrospinous Ligament
The sacrospinous ligament (small or anterior sacrosciatic ligament) is a thin, triangular ligament in the human pelvis. The base of the ligament is attached to the outer edge of the sacrum and coccyx, and the tip of the ligament attaches to the spine of the ischium, a bony protuberance on the human pelvis. Its fibres are intermingled with the sacrotuberous ligament. Structure The sacrotuberous ligament passes behind the sacrospinous ligament. In its entire length, the sacrospinous ligament covers the equally triangular coccygeus muscle, to which its closely connected.Gray's Anatomy 1918 Function The presence of the ligament in the greater sciatic notch creates an opening (foramen), the greater sciatic foramen, and also converts the lesser sciatic notch into the lesser sciatic foramen.Platzer (2004), p 188 The greater sciatic foramen lies above the ligament, and the lesser sciatic foramen lies below it. The pudendal vessels and nerve pass behind the sacrospinous ligament directl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
