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Lumbosacral Trunk
The lumbosacral trunk is nervous tissue that connects the lumbar plexus with the sacral plexus. Structure The lumbosacral trunk comprises the whole of the ventral rami of L5 and a part of L4. It appears at the medial margin of the psoas major and runs downward over the pelvic brim to join the first sacral nerve. The anterior division of the third sacral nerve divides into an upper and a lower branch, the former entering the sacral plexus and the latter the pudendal plexus. This connects the lumbar plexus and the sacral plexus. Clinical significance The lumbosacral trunk may be compressed by the fetal head during the second stage of labour. This causes some muscle weakness in the legs A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element .... A full recovery is usually expected. Ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbar Nerves
The lumbar nerves are the five pairs of spinal nerves emerging from the lumbar vertebrae. They are divided into posterior and anterior divisions. Structure The lumbar nerves are five spinal nerves which arise from either side of the spinal cord below the thoracic spinal cord and above the sacral spinal cord. They arise from the spinal cord between each pair of lumbar spinal vertebrae and travel through the intervertebral foramina. The nerves then split into an anterior branch, which travels forward, and a posterior branch, which travels backwards and supplies the area of the back. Posterior divisions The middle divisions of the posterior branches run close to the articular processes of the vertebrae and end in the multifidus muscle. The outer branches supply the erector spinae muscles. The nerves give off branches to the skin. These pierce the aponeurosis of the greater trochanter. Anterior divisions The anterior divisions of the lumbar nerves ( la, rami anteriores) increase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbar Plexus
The lumbar plexus is a web of nerves (a nervous plexus) in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the Ventral ramus of spinal nerve, divisions of the first four lumbar nerves (L1-L4) and from contributions of the subcostal nerve (T12), which is the last Thoracic nerves, thoracic nerve. Additionally, the ventral rami of the fourth lumbar nerve pass communicating branches, the lumbosacral trunk, to the sacral plexus. The nerves of the lumbar plexus pass in front of the hip joint and mainly support the anterior part of the thigh.''Thieme Atlas of anatomy'' (2006), pp 470-471 The plexus is formed lateral to the intervertebral foramina and passes through Psoas major muscle, psoas major. Its smaller motor branches are distributed directly to psoas major, while the larger branches leave the muscle at various sites to run obliquely down through the pelvis to leave under the inguinal ligament with the exception of the obturator n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacral Plexus
In human anatomy, the sacral plexus is a nerve plexus which provides motor and sensory nerves for the posterior thigh, most of the lower leg and foot, and part of the pelvis. It is part of the lumbosacral plexus and emerges from the lumbar vertebrae and sacral vertebrae (L4-S4).''Thieme Atlas of Anatomy'' (2006), pp 470-471 A sacral plexopathy is a disorder affecting the nerves of the sacral plexus, usually caused by trauma, nerve compression, vascular disease, or infection. Symptoms may include pain, loss of motor control, and sensory deficits. Structure The sacral plexus is formed by: * the lumbosacral trunk * the anterior division of the first sacral nerve * portions of the anterior divisions of the second and third sacral nerves The nerves forming the sacral plexus converge toward the lower part of the greater sciatic foramen, and unite to form a flattened band, from the anterior and posterior surfaces of which several branches arise. The band itself is continued as the sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventral Ramus Of Spinal Nerve
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, ventr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbar Nerves
The lumbar nerves are the five pairs of spinal nerves emerging from the lumbar vertebrae. They are divided into posterior and anterior divisions. Structure The lumbar nerves are five spinal nerves which arise from either side of the spinal cord below the thoracic spinal cord and above the sacral spinal cord. They arise from the spinal cord between each pair of lumbar spinal vertebrae and travel through the intervertebral foramina. The nerves then split into an anterior branch, which travels forward, and a posterior branch, which travels backwards and supplies the area of the back. Posterior divisions The middle divisions of the posterior branches run close to the articular processes of the vertebrae and end in the multifidus muscle. The outer branches supply the erector spinae muscles. The nerves give off branches to the skin. These pierce the aponeurosis of the greater trochanter. Anterior divisions The anterior divisions of the lumbar nerves ( la, rami anteriores) increase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psoas Major
The psoas major ( or ; from grc, ψόᾱ, psóā, muscles of the loins) is a long fusiform muscle located in the lateral lumbar region between the vertebral column and the brim of the lesser pelvis. It joins the iliacus muscle to form the iliopsoas. In animals, this muscle is equivalent to the tenderloin. Structure The psoas major is divided into a superficial and a deep part. The deep part originates from the transverse processes of lumbar vertebrae L1–L5. The superficial part originates from the lateral surfaces of the last thoracic vertebra, lumbar vertebrae L1–L4, and the neighboring intervertebral discs. The lumbar plexus lies between the two layers. Together, the iliacus muscle and the psoas major form the iliopsoas, which is surrounded by the iliac fascia. The iliopsoas runs across the iliopubic eminence through the muscular lacuna to its insertion on the lesser trochanter of the femur. The iliopectineal bursa separates the tendon of the iliopsoas muscle from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelvic Brim
The pelvic brim is the edge of the pelvic inlet. It is an approximately Mickey Mouse head-shaped line passing through the prominence of the sacrum, the arcuate and pectineal lines, and the upper margin of the pubic symphysis. Structure The pelvic brim is an approximately Mickey Mouse head-shaped line passing through the prominence of the sacrum, the arcuate and pectineal lines, and the upper margin of the pubic symphysis. The pelvic brim is obtusely pointed in front, diverging on either side, and encroached upon behind by the projection forward of the promontory of the sacrum. The oblique plane passing approximately through the pelvic brim divides the internal part of the pelvis (pelvic cavity) into the false or greater pelvis and the true or lesser pelvis. The false pelvis, which is above that plane, is sometimes considered to be a part of the abdominal cavity, rather than a part of the pelvic cavity. In this case, the pelvic cavity coincides with the true pelvis, which is b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacral Nerve
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] |
Pudendal Plexus (nerves)
The pudendal plexus is a term used for a compound structure consisting of sacral spinal nerves. Some sources describe it as S2-S4 of the lumbosacral plexus. In some older texts, it is a rough approximation of the coccygeal plexus The coccygeal plexus is a nerve plexus near the coccyx bone. Structure This plexus is formed by the ventral rami The ventral ramus (pl. ''rami'') (Latin for ''branch'') is the anterior division of a spinal nerve. The ventral rami supply the ant .... References Nerve plexus {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fetal Head
The fetal head, from an obstetrical viewpoint, and in particular its size, is important because an essential feature of labor is the adaptation between the fetal head and the maternal bony pelvis. Only a comparatively small part of the head at term is represented by the face. The rest of the head is composed of the firm skull, which is made up of two frontal, two parietal, and two temporal bones, along with the upper portion of the occipital bone and the wings of the sphenoid. These bones are separated by membranous spaces, or sutures. The most important sutures are the frontal, between the two frontal bones; the sagittal, between the two parietal bones; the two coronal, between the frontal and parietal bones; and the two lambdoid, between the posterior margins of the parietal bones and upper margin of the occipital bone. Where several sutures meet, an irregular space forms, which is enclosed by a membrane and designated as a fontanel. The greater, or anterior fontanel, is a lozen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Childbirth
Childbirth, also known as labour and delivery, is the ending of pregnancy where one or more babies exits the internal environment of the mother via vaginal delivery or caesarean section. In 2019, there were about 140.11 million births globally. In the developed countries, most deliveries occur in hospitals, while in the developing countries most are home births. The most common childbirth method worldwide is vaginal delivery. It involves four stages of labour: the shortening and opening of the cervix during the first stage, descent and birth of the baby during the second, the delivery of the placenta during the third, and the recovery of the mother and infant during the fourth stage, which is referred to as the postpartum. The first stage is characterized by abdominal cramping or back pain that typically lasts half a minute and occurs every 10 to 30 minutes. Contractions gradually becomes stronger and closer together. Since the pain of childbirth correlates with contractions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
