|
Lumbar Spinal Nerve 4
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 () increase in size from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbar Plexus
The lumbar plexus is a web of nerves (a nerve plexus) in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the divisions of the first four lumbar nerves (L1–L4) and from contributions of the subcostal nerve (T12), which is the last 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. 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 nerve which exits the pelvis through the obturator foramen. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbar Ganglia
The lumbar ganglia are paravertebral ganglia located in the inferior portion of the sympathetic trunk. The lumbar portion of the sympathetic trunk typically has 4 lumbar ganglia. The lumbar splanchnic nerves arise from the Ganglion, ganglia here, and contribute sympathetic efferent fibers to the nearby plexuses. The first two lumbar ganglia have both white and gray rami communicates. Function Paravertebral ganglia are divided into cervical, thoracic, lumbar, and sacral ganglia. Each controls different glands and muscle groups since each muscle and gland receives input from postganglionic neurons that originated from different levels of paravertebral ganglia. The lumbar part of the sympathetic trunk contains four interconnected ganglia. Superiorly, it is continuous with thoracic sympathetic ganglion and inferiorly continuous with sacral sympathetic ganglion. Presynaptic neurons traveling from the spinal cord terminate in the paravertebral ganglia (cervical, thoracic, lumbar, sacral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iliohypogastric
The iliohypogastric nerve is a nerve that originates from the lumbar plexus that supplies sensation to skin over the lateral gluteal and hypogastric regions and motor to the internal oblique muscles and transverse abdominal muscles. Structure Origin The iliohypogastric nerve originates from the superior branch of the anterior ramus of spinal nerve L1. It also receives fibers from T12 via the subcostal nerve. The branch below it is the ilioinguinal nerve. Course It emerges from the upper lateral border of the psoas major. It then crosses in front of the quadratus lumborum muscle to an area superior to the iliac crest. It runs behind the kidneys. Just superior to the iliac crest, it pierces the posterior part of the transversus abdominis muscle and continues anteriorly in the abdominal wall between the transversus abdominis and internal oblique muscles. It divides into a lateral cutaneous branch and an anterior cutaneous branch between the transversus abdominis muscle a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbar Vertebra 1
The lumbar vertebrae are located between the thoracic vertebrae and pelvis. They form the lower part of the back in humans, and the tail end of the back in quadrupeds. In humans, there are five lumbar vertebrae. The term is used to describe the anatomy of humans and quadrupeds, such as horses, pigs, or cattle. These bones are found in particular cuts of meat, including tenderloin or sirloin steak. Human anatomy In human anatomy, the five vertebrae are between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse process (since it is only found in the cervical region) and by the absence of facets on the sides of the body (as found only in the thoracic region). They are designated L1 to L5, starting at the top. The lumbar vertebrae help support the weight of the body, and permit movement. General characteristics The adjacent figure depicts the general charac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furcal Nerve
The furcal nerve (forked nerve) links the lumbar plexus and the sacral plexus. It has its own dorsal and ventral branches with fibres that branch out to become part of the femoral and obturator nerves. The furcal nerve is found in the lumbosacral trunk most commonly at the level of the fourth lumbar vertebra (L4). Structure and location The furcal nerve is an independent nerve that links the lumbar plexus to the sacral plexus. It is most commonly found at the level of the fourth lumbar vertebra. The next most common site is the level of the third lumbar vertebra (L3). The furcal nerve can be found at any level from L1 to S1 but has not been reported at L1. Occasionally a double furcal nerve is found. It gives branches to the femoral nerve, lumbosacral trunk, and obturator nerve The obturator nerve in human anatomy arises from the ventral divisions of the second, third, and fourth lumbar nerves in the lumbar plexus; the branch from the third is the largest, while that from the ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbosacral Trunk
The lumbosacral trunk is nervous tissue that connects the lumbar plexus with the sacral plexus. It is formed by the union of parts of the fourth and fifth lumbar nerves and descends to join the sacral plexus. Anatomy The lumbosacral trunk is formed by the union of the entire anterior ramus of lumbar nerve L5 . L4 first issues its branches to the lumbar plexus, then emerges from the medial border of the psoas muscle to unite with the anterior ramus of L5 just superior to the pelvic brim to form the thick, cord-like trunk which crosses the pelvic brim (medial to the obturator nerve) to descend upon the anterior surface of the ala of sacrum before joining the sacral plexus. Like the sacral nerves, the lumbosacral trunks splits into an anterior division and a posterior division before recombining to form nerves for the flexor and extensor compartments of the lower limb. Clinical significance The lumbosacral trunk may be compressed by the fetal head during the second stage of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nervous Plexus
A nerve plexus is a plexus (branching network) of intersecting nerves. A nerve plexus is composed of afferent and efferent fibers that arise from the merging of the anterior rami of spinal nerves and blood vessels. There are five spinal nerve plexuses, except in the thoracic region, as well as other forms of autonomic plexuses, many of which are a part of the enteric nervous system. The nerves that arise from the plexuses have both sensory and motor functions. These functions include muscle contraction, the maintenance of body coordination and control, and the reaction to sensations such as heat, cold, pain, and pressure. There are several plexuses in the body, including: *Spinal plexuses **Cervical plexusserves the head, neck and shoulders **Brachial plexusserves the chest, shoulders, arms and hands **Lumbosacral plexus ***Lumbar plexusserves the back, abdomen, groin, thighs, knees, and calves **** Subsartorial plexusbelow the sartorius muscle of thigh ***Sacral plexusserves the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadratus Lumborum
The quadratus lumborum muscle, informally called the ''QL'', is a paired muscle of the left and right posterior abdominal wall. It is the deepest abdominal muscle, and commonly referred to as a back muscle. Each muscle of the pair is an irregular quadrilateral in shape, hence the name. The quadratus lumborum muscles originate from the wings of the ilium; their insertions are on the transverse processes of the upper four lumbar vertebrae plus the lower posterior border of the twelfth rib. Contraction of one of the pair of muscles causes lateral flexion of the lumbar spine, ''elevation'' of the pelvis, or both. Contraction of both causes ''extension'' of the lumbar spine. A disorder of the quadratus lumborum muscles is pain due to muscle fatigue from constant contraction due to prolonged sitting, such as at a computer or in a car.Core Topics in Pain, p. 131, Anita Holdcraft and Sian Jaggar, 2005. Kyphosis and weak gluteal muscles can also contribute to the likelihood of quadratu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle Fascicle
A muscle fascicle is a bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue. Structure Muscle cells are grouped into muscle fascicles by enveloping perimysium connective tissue. Fascicles are bundled together by epimysium connective tissue. Muscle fascicles typically only contain one type of muscle cell (either type I fibres or type II fibres), but can contain a mixture of both types. Function In the heart, specialized cardiac muscle cells transmit electrical impulses from the atrioventricular node (AV node) to the Purkinje fibers – fascicles, also referred to as bundle branches. These start as a single fascicle of fibers at the AV node called the bundle of His that then splits into three bundle branches: the right fascicular branch, left anterior fascicular branch, and left posterior fascicular branch. Clinical significance Myositis may cause thickening of the muscle fascicles. This may be detected with ultrasound scans. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Ramus Communicans
The white ramus communicans (: rami communicantes) from Latin ramus (branch) and communicans (communicating) is the preganglionic sympathetic outflow nerve tract from the spinal cord. Each of the thoracic, and the first and second lumbar nerves contribute a white ramus communicans to the adjoining sympathetic ganglion, unlike the gray rami which are located at each spinal level. White rami communicantes contain both myelinated and unmyelinated preganglionic sympathetic fibers, ( GVE and GVA). The white ramus appears white because there are more myelinated than unmyelinated fibers unlike the gray rami. Structure The white rami communicantes are the preganglionic sympathetic outflow from the spinal cord. The cell bodies for the preganglionic sympathetic myelinated fibers in the white rami communicantes lie in the ipsilateral (same sided) intermediolateral cell column in the spinal cord which extends from T1-L2. These rami also contain general visceral afferent fibers (sensory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganglia
A ganglion (: ganglia) is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system, this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system, there are both sympathetic and parasympathetic ganglia which contain the cell bodies of postganglionic sympathetic and parasympathetic neurons respectively. A pseudoganglion looks like a ganglion, but only has nerve fibers and has no nerve cell bodies. Structure Ganglia are primarily made up of somata and dendritic structures, which are bundled or connected. Ganglia often interconnect with other ganglia to form a complex system of ganglia known as a plexus. Ganglia provide relay points and intermediary connections between different neurological structures in the body, such as the peripheral and central nervous systems. Among vertebrates there are three major groups of ganglia: * Dorsal root ganglia (also known as the spinal ganglia) cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
