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Nerve Roots
A nerve root () is the initial segment of a nerve leaving the central nervous system. Nerve roots can be classified as: * Cranial nerve roots: the initial or proximal segment of one of the twelve pairs of cranial nerves leaving the central nervous system from the brain stem or the highest levels of the spinal cord. * Spinal nerve roots: the initial or proximal segment of one of the 31 pairs of spinal nerves leaving the central nervous system from the spinal cord. Each spinal nerve is a mixed nerve formed by the union of a sensory dorsal root and a motor ventral root, meaning that there are 62 dorsal/ventral root pairs, and therefore 124 nerve roots in total, each of which stems from a bundle of nerve rootlets (or root filaments). Cranial nerve roots Cranial nerves originate directly from the brain's surface: two from the cerebrum and the ten others from the brain stem. Cranial roots differ from spinal roots: some of these roots do not separate into individual sensory (dorsal) and mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the Electrochemistry, electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system. Each axon is an extension of an individual neuron, along with other supportive cells such as some Schwann cells that coat the axons in myelin. Each axon is surrounded by a layer of connective tissue called the endoneurium. The axons are bundled together into groups called Nerve fascicle, fascicles, and each fascicle is wrapped in a layer of connective tissue called the perineurium. The entire nerve is wrapped in a layer of connective tissue called the epineurium. Nerve cells (often called neurons) are further classified as either Sensory neuron, sens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paresis
In medicine, paresis (), compound word from Greek , (πᾰρᾰ- “beside” + ἵημι “let go, release”), is a condition typified by a weakness of voluntary movement, or by partial loss of voluntary movement or by impaired movement. When used without qualifiers, it usually refers to the limbs, but it can also be used to describe the muscles of the eyes ( ophthalmoparesis), the stomach (gastroparesis), and also the vocal cords ( vocal cord paresis). Neurologists use the term ''paresis'' to describe weakness, and ''plegia'' to describe paralysis in which all voluntary movement is lost. The term ''paresis'' comes from the 'letting go' from παρίημι 'to let go, to let fall'. Types Limbs * Monoparesis – One leg or one arm * Paraparesis – Both legs * Hemiparesis – The loss of function to only one side of the body * Triparesis – Three limbs. This can either mean both legs and one arm, both arms and a leg, or a combination of one arm, one leg, and face * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiculopathy
Radiculopathy (; ), also commonly referred to as pinched nerve, refers to a set of conditions in which one or more nerves are affected and do not work properly (a neuropathy). Radiculopathy can result in pain (radicular pain), weakness, altered sensation (paresthesia) or difficulty controlling specific muscles. Pinched nerves arise when surrounding bone or tissue, such as cartilage, muscles or tendons, put pressure on the nerve and disrupt its function. In a radiculopathy, the problem occurs at or near the root of the nerve, shortly after its exit from the spinal cord. However, the pain or other symptoms often radiate to the Dermatome (anatomy), part of the body Myotome, served by that nerve. For example, a nerve root impingement in the neck can produce pain and weakness in the forearm. Likewise, an impingement in the lower back or lumbar-sacrum, sacral Vertebral column, spine can be manifested with symptoms in the foot. The radicular pain that results from a radiculopathy should ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sciatica
Sciatica is pain going down the leg from the lower back. This pain may go down the back, outside, or front of the leg. Onset is often sudden following activities such as heavy lifting, though gradual onset may also occur. The pain is often described as shooting. Typically, symptoms are only on one side of the body. Certain causes, however, may result in pain on both sides. Lower back pain is sometimes present. Weakness or numbness may occur in various parts of the affected leg and foot. About 90% of sciatica is due to a spinal disc herniation pressing on one of the lumbar or sacral nerve roots. Spondylolisthesis, spinal stenosis, piriformis syndrome, pelvic tumors, and pregnancy are other possible causes of sciatica. The straight-leg-raising test is often helpful in diagnosis. The test is positive if, when the leg is raised while a person is lying on their back, pain shoots below the knee. In most cases medical imaging is not needed. However, imaging may be obtained if bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiculitis
Radicular pain, or radiculitis (from the ), is pain "radiated" along the dermatome (sensory distribution) of a nerve due to inflammation or other irritation of the nerve root (radiculopathy) at its connection to the spinal column. A common form of radiculitis is sciatica – radicular pain that radiates along the sciatic nerve from the lower spine to the lower back, gluteal muscles, back of the upper thigh, calf, and foot as often secondary to nerve root irritation from a spinal disc herniation or from osteophytes in the lumbar region of the spine. Radiculitis indicates inflammation of the spinal nerve root, which may lead to pain in that nerve's distribution without weakness – as opposed to radiculopathy. When the radiating pain is associated with numbness or weakness, the diagnosis is radiculopathy if the lesion is at the nerve root, or myelopathy if at the spinal cord itself. See also * Intervertebral disc * Spinal disc herniation A disc herniation or spinal disc hern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore is considered a mechanism of innate immunity, whereas adaptive immunity is specific to each pathogen. Inflammation is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out damaged cells and tissues, and initiate tissue repair. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. bacteria) and compromise the survival of the organism. However inflammation can also have negative effects. Too much inflammation, in the form of chronic inflammation, is associated with variou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer
Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible Signs and symptoms of cancer, signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in defecation, bowel movements. While these symptoms may indicate cancer, they can also have other causes. List of cancer types, Over 100 types of cancers affect humans. Tobacco use is the cause of about 22% of cancer deaths. Another 10% are due to obesity, poor Diet (nutrition), diet, sedentary lifestyle, lack of physical activity or Alcohol abuse, excessive alcohol consumption. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. infectious causes of cancer, Infection with specific viruses, bacteria and parasites is an environmental factor cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Tuberculosis
Pott's disease, or Pott disease, named for British surgeon Percivall Pott who first described the symptoms in 1799, is tuberculosis of the spine, usually due to haematogenous spread from other sites, often the lungs. The lower thoracic and upper lumbar vertebrae areas of the spine are most often affected. It causes a kind of tuberculous arthritis of the intervertebral joints. The infection can spread from two adjacent vertebrae into the adjoining intervertebral disc space. If only one vertebra is affected, the disc is normal, but if two are involved, the disc, which is avascular, cannot receive nutrients, and collapses. In a process called caseous necrosis, the disc tissue dies, leading to vertebral narrowing and eventually to vertebral collapse and spinal damage. A dry soft-tissue mass often forms and superinfection is rare. Spread of infection from the lumbar vertebrae to the psoas muscle, causing abscesses, is not uncommon. Diagnosis The most common and earliest clinica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleus Pulposus
An intervertebral disc (British English), also spelled intervertebral disk (American English), lies between adjacent vertebrae in the vertebral column. Each disc forms a fibrocartilaginous joint (a symphysis), to allow slight movement of the vertebrae, to act as a ligament to hold the vertebrae together, and to function as a shock absorber for the spine. Structure Intervertebral discs consist of an outer fibrous ring, the ''anulus (or annulus) fibrosus disci intervertebralis'', which surrounds an inner gel-like center, the ''nucleus pulposus''. The ''anulus fibrosus'' consists of several layers (laminae) of fibrocartilage made up of both type I and type II collagen. Type I is concentrated toward the edge of the ring, where it provides greater strength. The stiff laminae can withstand compressive forces. The fibrous intervertebral disc contains the ''nucleus pulposus'' and this helps to distribute pressure evenly across the disc. This prevents the development of stress concen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lesion
A lesion is any damage or abnormal change in the tissue of an organism, usually caused by injury or diseases. The term ''Lesion'' is derived from the Latin meaning "injury". Lesions may occur in both plants and animals. Types There is no designated classification or naming convention for lesions. Because lesions can occur anywhere in the body and their definition is so broad, the varieties of lesions are virtually endless. Generally, lesions may be classified by their patterns, sizes, locations, or causes. They can also be named after the person who discovered them. For example, Ghon lesions, which are found in the lungs of those with tuberculosis, are named after the lesion's discoverer, Anton Ghon. The characteristic skin lesions of a varicella zoster virus infection are called '' chickenpox''. Lesions of the teeth are usually called dental caries, or "cavities". Location Lesions are often classified by their tissue types or locations. For example, "skin lesions" or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerveroot
''Cypripedium parviflorum'', commonly known as yellow lady's slipper or moccasin flower, is a lady's slipper orchid native to North America. It is widespread, ranging from Alaska south to Arizona and Georgia (U.S. state), Georgia. It grows in fens, wetlands, shorelines, and damp woodlands. Description * Plant: 16 to 60 cm tall, reported to 80 cm elsewhere: stem, bracts, and leaves pubescent; flower stem rises 10 cm above leaves; one flower, rarely two. * Roots: few to many slender roots to 4 cm long on jointed rhizome. * Leaves: ovate lanceolate, cauline, plicate, four to six on blooming plants, from 9 ⨉ 4 cm to 14 ⨉ 5 cm; covered with fine hairs on underside; a few hairs on topside. * Floral bracts: ovate lanceolate bract at base of ovary, 7 ⨉ 2 cm. * Flowers: bright yellow pouch with greenish to reddish sepals and petals; up to 10 cm high ⨉ 10 cm wide. * Sepals: yellowish green with reddish stripes that turn to dots near p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
