What nerve Innervates the main elbow flexors? ulnar nerve.
Conclusion: Gross dissections suggest that the female levator ani muscle is not innervated by the pudendal nerve but rather by innervation that originates the sacral nerve roots (S3-S5) that travels on the superior surface of the pelvic floor (levator ani nerve).
Our opinion is that the puborectalis muscle (middle layer of pelvic floor muscle) is actually innervated by the pudendal nerve24 (from below) and the deep muscles (pubococcygeus, ileococcygeus and coccygeus) are innervated by the direct branches of sacral nerve roots S3 & S43.
|Nerve||Pudendal nerve; sacral nerves: S4, S5 or S3-S4|
|Actions||pulls coccyx forward after defecation, closing in the back part of the outlet of the pelvis|
The puborectalis muscle, separated from the external anal sphincter by a fascial layer, is innervated by direct somatic efferent nerves from the sacral plexus,5,6 whereas the external anal sphincter muscle receives its innervation from the inferior rectal branches of the pudendal nerves.
The pudendal nerve has both motor and sensory functions. It does not carry parasympathetic fibers but does carry sympathetic fibers.
Pudendal canal, also known as Alcock’s canal, is a sheath derived from the fascia of the obturator internus muscle, and is found in the lower lateral wall of the ischiorectal fossa.
Although the puborectalis and external anal sphincter muscle form a functional unit in maintaining continence, developmental studies provide evidence that the puborectalis is anatomically a part of the levator ani muscle.
|Anatomical terms of muscle|
coccygeus muscle, muscle of the lower back that arises from the ischium (lower, rear portion of the hipbone) and from the ligaments that join the spinal column and the sacrum (triangular bone at the base of the spine). It is attached to the lower sacrum and the coccyx (tailbone).
The bilateral coccygeal nerves, Co, are the 31st pair of spinal nerves. It arises from the conus medullaris, and its ventral ramus helps form the coccygeal plexus. It does not divide into a medial and lateral branch.
The piriformis muscle rotates the femur during the hip extension and abducts the femur during flexion of the hip.
Structure. Puborectalis is a thick narrow, medial part of the levator ani. It forms a U-shaped muscular sling around and behind the rectum, just cephalad to the external sphincter.
: a band of muscle fibers that is part of the pubococcygeus, that passes from the pubic symphysis to interdigitate with the contralateral band of fibers forming a sling around the rectum at its junction with the anal canal, and that acts to hold the rectum and anal canal at right angles to each other except during …
The superficial layer of the LAM, made of skeletal fibers, appears to represent the functional mobile part that acts voluntarily during urination or defecation.
After passing through to the intravertebral foramen, the nerve divides into a dorsal ramus and a ventral ramus . Whereas the autonomic (parasympathetic) fibers constitute the pelvic plexus, the somatic fibers from the ventral rami (also called the sacral plexus) form the pudendal nerve.
The pudendal nerve is paired, meaning there are two nerves, one on the left and one on the right side of the body. Motor – innervates various pelvic muscles, the external urethral sphincter and the external anal sphincter.
Within the Alcock canal, the pudendal nerve divides into the inferior rectal nerve, perineal nerve, and dorsal nerve of the penis/clitoris . Given that the pudendal nerve can divide quite proximally, peripheral nerve stimulation at the Alcock canal may have more varied results.
Ischiorectal fossae are located in the lateral part of the anal triangle on either side of the anal canal. They are pyramida/wedge shaped , with apex directed upwards and base downwards. they are fat filled spaces that help in dilatation of anal canal during defecation.
The pudendal block gets its name because a local anesthetic, such as lidocaine or chloroprocaine, is injected into the pudendal canal where the pudendal nerve is located. This allows quick pain relief to the perineum, vulva, and vagina.
The obturator nerve arises from the lumbar plexus and provides sensory and motor innervation to the thigh. This nerve provides motor innervation to the medial compartment of the thigh and as a result, is essential to the adduction of the thigh.
This muscle is innervated by the obturator internus nerve (L5–S2).
The coccygeus (or ischiococcygeus) is the smaller, and most posterior pelvic floor component – as the levator ani muscles are situated anteriorly. It originates from the ischial spines and travels to the lateral aspect of the sacrum and coccyx, along the sacrospinous ligament.
The levator palpebrae superioris muscle origin is the periosteum of the lesser wing of the sphenoid bone, superior to the optic foramen. The muscle travels anteriorly along the superior aspect of the orbit superior to the superior rectus muscle.
Conclusion: We characterized the muscular structure and neural control of the levator ani muscle. The muscle consists of a medial part containing smooth muscle cells under autonomic nerve influence and a lateral part containing striated muscle cells under somatic nerve control.
The Iliococcygeus arises from the ischial spine and from the posterior part of the tendinous arch of the pelvic fascia, and is attached to the coccyx and anococcygeal raphé; it is usually thin, and may fail entirely, or be largely replaced by fibrous tissue.
It contains the penis and scrotum in males and mons pubis, labia majora and minora, clitoris and vaginal and urethral orifices in females.
Introduction. The levator ani is a complex funnel-shaped structure mainly composed of striated muscle, with some smooth muscle component. Located on either side of the lower pelvis, it takes part in supporting and raising the pelvic floor and allows various pelvic structures to pass through it.
The piriformis muscle originates at the internal surface of the sacrum and inserts at the superior border of the trochanter of the femur. It functions in helping lateral rotation of the hip joint, abducting the thigh when the hip is flexed, and assisting stability of the head of the femur in the acetabulum.
The anococcygeal body (anococcygeal ligament, or anococcygeal raphe) is a fibrous median raphe in the floor of the pelvis, which extends between the coccyx and the margin of the anus.
S1 affects the hips and groin area. S2 affects the back of the thighs. S3 affects the medial buttock area. S4 & S5 affect the perineal area.
The S5 roots and coccygeal nerves leave the sacral canal via the sacral hiatus. These nerves provide sensory and motor innervation to their respective dermatomes and myotomes. They also provide partial innervation to several pelvic organs, including the uterus, fallopian tubes, bladder, and prostate.
C1, C2, and C3 (the first three cervical nerves) help control the head and neck, including movements forward, backward, and to the sides.
The present study found that the superior gluteal nerve, and S1 and S2 ventral rami are the main contributors to the innervation of the pir- iformis muscles.
Innervation. The superior gemellus muscle is innervated by the nerve to obturator internus (L5, S1, S2), a branch of the sacral plexus. The nerve exits the pelvis via the greater sciatic foramen inferior to the piriformis muscle and typically between the posterior cutaneous nerve of the thigh and the pudendal nerve.
The piriformis is a small muscle located deep in the buttock, behind the gluteus maximus. It runs diagonally from the lower spine to the upper surface of the femur, with the sciatic nerve running underneath or through the muscle. The piriformis muscle helps the hip rotate, turning the leg and foot outward.
The iliococcygeus muscles arise from the lateral pubic symphysis, travel over the pelvic sidewall (i.e., obturator internus muscle) attached to the arcus tendineus levator ani laterally, and meet in the midline at the anococcygeal raphe and the coccyx to form the levator plate (see Fig.
The perineal membrane is an anatomical term for a fibrous membrane in the perineum. The term “inferior fascia of urogenital diaphragm”, used in older texts, is considered equivalent to the perineal membrane. It is the superior border of the superficial perineal pouch, and the inferior border of the deep perineal pouch.
Abstract. Background: Paradoxical puborectalis contraction (PPC) is a syndrome of obstructed defecation associated with a cluster of complaints including rectal pain, incomplete evacuatory sensation, prolonged repetitive straining with bowel movements, and the need for digital manipulation.
Paradoxical puborectalis contraction is associated with a cluster of complaints including rectal pain, incomplete evacuatory sensation, prolonged repetitive straining with bowel movements, and the need for digital manipulation.