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Pathophysiology Of Multiple Sclerosis
Multiple sclerosis is an inflammatory demyelinating disease of the CNS in which activated immune cells invade the central nervous system and cause inflammation, neurodegeneration, and tissue damage. The underlying cause is currently unknown. Current research in neuropathology, neuroimmunology, neurobiology, and neuroimaging, together with clinical neurology, provide support for the notion that MS is not a single disease but rather a spectrum. There are three clinical phenotypes: relapsing-remitting MS (RRMS), characterized by periods of neurological worsening following by remissions; secondary-progressive MS (SPMS), in which there is gradual progression of neurological dysfunction with fewer or no relapses; and primary-progressive MS (MS), in which neurological deterioration is observed from onset. Pathophysiology is a convergence of pathology with physiology. Pathology is the medical discipline that describes conditions typically observed during a disease state; whereas physiolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammatory Demyelinating Diseases Of The CNS
Inflammatory demyelinating diseases (IDDs), sometimes called Idiopathic (IIDDs) due to the unknown etiology of some of them, are a heterogenous group of demyelinating diseases - conditions that cause damage to myelin, the protective sheath of nerve fibers - that occur against the background of an acute or chronic Inflammation, inflammatory process. IDDs share characteristics with and are often grouped together under Multiple sclerosis, Multiple Sclerosis. They are sometimes considered different diseases from Multiple Sclerosis, but considered by others to form a spectrum differing only in terms of chronicity, severity, and clinical course. Multiple sclerosis for some people is a syndrome more than a single disease. As of 2019, three auto-antibodies have been found in atypical MS giving birth to separate diseases: Anti-AQP4 diseases, AntiMOG associated encephalomyelitis, Anti-MOG and Anti-neurofascin demyelinating diseases, Anti-NF spectrums. A Leber's hereditary optic neuropathy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myelin
Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However, unlike the plastic covering on an electrical wire, myelin does not form a single long sheath over the entire length of the axon. Rather, myelin sheaths the nerve in segments: in general, each axon is encased with multiple long myelinated sections with short gaps in between called nodes of Ranvier. Myelin is formed in the central nervous system (CNS; brain, spinal cord and optic nerve) by glial cells called oligodendrocytes and in the peripheral nervous system (PNS) by glial cells called Schwann cells. In the CNS, axons carry electrical signals from one nerve cell body to another. In the PNS, axons carry signals to muscles and glands or from senso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectopia (medicine)
An ectopia () is a displacement or malposition of an organ or other body part, which is then referred to as ectopic ({{IPAc-en, ɛ, k, ˈ, t, ɒ, p, ɪ, k). Most ectopias are congenital, but some may happen later in life. Examples *Ectopic ACTH syndrome, also known as small-cell carcinoma. *Ectopic calcification, a pathologic deposition of calcium salts in tissues or bone growth in soft tissues * Cerebellar tonsillar ectopia, aka Chiari malformation, a herniation of the brain through the foramen magnum, which may be congenital or caused by trauma. * Ectopic cilia, a hair growing where it isn't supposed to be, commonly an eyelash on an abnormal spot on the eyelid, distichia *Ectopia cordis, the displacement of the heart outside the body during fetal development * Ectopic enamel, a tooth abnormality, where enamel is found in an unusual location, such as at the root of a tooth *Ectopic expression, the expression of a gene in an abnormal place in an organism * Ectopic hormone, a horm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meninges
In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in the subarachnoid space between the arachnoid mater and the pia mater. The primary function of the meninges is to protect the central nervous system. Structure Dura mater The dura mater ( la, tough mother) (also rarely called ''meninx fibrosa'' or ''pachymeninx'') is a thick, durable membrane, closest to the Human skull, skull and vertebrae. The dura mater, the outermost part, is a loosely arranged, fibroelastic layer of cells, characterized by multiple interdigitating cell processes, no extracellular collagen, and significant extracellular spaces. The middle region is a mostly fibrous portion. It consists of two layers: the endosteal layer, which lies closest to the Calvaria (skull), skull, and the inner meningeal layer, which lies closer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Follicle (anatomy)
A follicle is a small, spherical or vase-like group of cells enclosing a cavity in which some other structure grows or other material is contained. Thyroid follicles make up the thyroid gland. Follicles are best known as the sockets from which hairs grow in humans and other mammals, but the bristles of annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ... worms also grow from such sockets. References {{reflist Skin anatomy Cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrocytes
Astrocytes (from Ancient Greek , , "star" + , , "cavity", "cell"), also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord. They perform many functions, including biochemical control of endothelial cells that form the blood–brain barrier, provision of nutrients to the nervous tissue, maintenance of extracellular ion balance, regulation of cerebral blood flow, and a role in the repair and scarring process of the brain and spinal cord following infection and traumatic injuries. The proportion of astrocytes in the brain is not well defined; depending on the counting technique used, studies have found that the astrocyte proportion varies by region and ranges from 20% to 40% of all glia. Another study reports that astrocytes are the most numerous cell type in the brain. Astrocytes are the major source of cholesterol in the central nervous system. Apolipoprotein E transports cholesterol from astrocytes to neurons and other glial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood–brain Barrier
The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that prevents solutes in the circulating blood from ''non-selectively'' crossing into the extracellular fluid of the central nervous system where neurons reside. The blood–brain barrier is formed by endothelial cells of the Capillary, capillary wall, astrocyte end-feet ensheathing the capillary, and pericytes embedded in the capillary basement membrane. This system allows the passage of some small molecules by passive transport, passive diffusion, as well as the selective and active transport of various nutrients, ions, organic anions, and macromolecules such as glucose and amino acids that are crucial to neural function. The blood–brain barrier restricts the passage of pathogens, the diffusion of solutes in the blood, and Molecular mass, large or Hydrophile, hydrophilic molecules into the cerebrospinal fluid, while allowing the diffusion of Hydr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligoclonal Bands
Oligoclonal bands (OCBs) are bands of immunoglobulins that are seen when a patient's blood serum, or cerebrospinal fluid (CSF) is analyzed. They are used in the diagnosis of various neurological and blood diseases, especially in multiple sclerosis. Two methods of analysis are possible: (a) protein electrophoresis, a method of analyzing the composition of fluids, also known as "SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis)/Coomassie blue staining", and (b) the combination of isoelectric focusing/silver staining. The latter is more sensitive. For the analysis of cerebrospinal fluid, a sample is first collected via lumbar puncture (LP). Normally it is assumed that all the proteins that appear in the CSF, but are not present in the serum, are produced intrathecally (inside the central nervous system). Therefore, it is normal to subtract bands in serum from bands in CSF when investigating CNS diseases. A sample of blood serum is usually obtained from a clotted bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunoglobulin
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can ''tag'' a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion). To allow the immune system to recognize millions of different antigens, the antigen-binding sites at both tips of the antibody come in an equally wide variety. In contrast, the remainder of the antibody is relatively constant. It only occurs in a few vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intrathecal
Intrathecal administration is a route of administration for drugs via an injection into the spinal canal, or into the subarachnoid space so that it reaches the cerebrospinal fluid (CSF) and is useful in spinal anesthesia, chemotherapy, or pain management applications. This route is also used to introduce drugs that fight certain infections, particularly post-neurosurgical. The drug needs to be given this way to avoid being stopped by the blood–brain barrier. The same drug given orally must enter the blood stream and may not be able to pass out and into the brain. Drugs given by the intrathecal route often have to be compounded specially by a pharmacist or technician because they cannot contain any preservative or other potentially harmful inactive ingredients that are sometimes found in standard injectable drug preparations. The route of administration is sometimes simply referred to as "intrathecal"; however, the term is also an adjective that refers to something occurring in or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and 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 necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and Functio laesa, loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immune system, innate immunity, as compared to adaptive immune system, adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray Matter
Grey matter is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and unmyelinated axons), glial cells (astrocytes and oligodendrocytes), synapses, and capillaries. Grey matter is distinguished from white matter in that it contains numerous cell bodies and relatively few myelinated axons, while white matter contains relatively few cell bodies and is composed chiefly of long-range myelinated axons. The colour difference arises mainly from the whiteness of myelin. In living tissue, grey matter actually has a very light grey colour with yellowish or pinkish hues, which come from capillary blood vessels and neuronal cell bodies. Structure Grey matter refers to unmyelinated neurons and other cells of the central nervous system. It is present in the brain, brainstem and cerebellum, and present throughout the spinal cord. Grey matter is distributed at the surface of the cerebral hemispheres (cerebral cortex) and of the cerebellum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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