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the kneelsit GLOSSARY Pg.7

medical and general terms relating to posture, sitting, musculoskeletal and back problems

ABBREVIATIONS:- Gr.= Greek; L.= Latin; Fr.= French; Ger = German; NA = Nomina Anatomica

M.

Macrophage, macrophagus (mak'ro-faj, mak-rof'a-gus) [" + phagein, to eat]. cells of the reticuloendothelial system having the ability to phagocytose particulate subtances and to store vital dyes and other colloidal substances. They are found in loose connective tissues and various organs of the body. They include Kupffer cells of the liver, splenocytes of the spleen, dust cells of the lung, microglia of spinal cord and brain, and histiocytes of loose connective tissue.

meningitis (men-in-ji'tis) [" + itis, inflammation]. (pl. meningitides) Inflammation of the membranes of the spinal cord or brain. SEE: choriomeningitis; Kernig's sign; leptomeningitis; pachymeningitis.
m., acute. SYM: Moderate, irregular fever; loss of appetite; constipation; intense headache; intolerance to light and sound; contracted pupils; delirium; retraction of head; convulsions; and coma. ETIOL: Caused by bacteria, viruses, or other organisms that reach the meninges from other foci in the body via blood or lymph, through trauma, or from adjacent bony structures (sinuses, mastoid cells).
TREAT: Antibiotics such as ampicillin, penicillin G, chloramphenicol, kanamycin, and gentamicin are the drugs of choice if the organism is susceptible. Supportive symptomatic therapy is also indicated. DIET: A fluid diet is necessary during the acute stage, but later a general diet should be given. Tube feeding is necessary with stuporous patients; and children and some adults may have to be fed with a spoon or a medicine dropper. PROG: Favorable with prompt diagnosis and appropriate therapy. m., cerebral. Acute or chronic meningitis of the brain.
m., cerebrospinal. Meningitis of brain and spinal cord.
m., spinal. Meningitis of spinal cord membranes.

meningoencephalomyelitis (men-in"go-en-sefal-o-mi-el-i'tis) [" + " myelos, marrow, + itis, inflammation]. inflammation of the brain, spinal cord, and their meninges meningomyelitis (men-in"go-mi-el-i'tis) [" + myelos, marrow, + itis, inflammation]. Inflammation of spinal cord and its enveloping arachnoid and pia mater, and, less commonly, of the dura mater.

meningomyelocele (men-in"go-mi-el'o-seI) ["+" kele, tumor, swelling]. Hernia of the spinal cord and membranes through a defect in the vertebral column.

meningomyeloradiculitis (me-ning"go -mi"e-lo-ra-dic"u-li tis) ["+ `L. radicula, radicle, + Gr. itis, inflammation]. Inflammation of the meninges, spinal cord, and brain.

meningo-osteophlebitis (me-ning"go-os" te-o-fle-bi'tis) [" + osteoa, bone, + phleps, vein, + itis, inflammation]. Parosteitis and inflammation of the veins of the bone.

meningopathy (men-in-gop'a-the) [" + pathos, disease, suffering]. Any pathological condition of the meninges.

meningoradicular (me-ning"go-ra-dik'ular) ["+ L. radicula, radicle]. Concerning the meninges and spinal and cerebral nerve roots.

meningoradiculitis (me-ning"go-ra-dik"uli'tis) [" + " + Gr. itis, inflammation). Inflammation of the meninges and roots of the spinal nerves.

meningorrhachidian (men-in"go-ra-kid'ean) [" + rhachis, spine). Concerning the spinal cord and meninges.

meningorrhagia (men-in"go-ra'je-a) [" + rhegnynai, to burst forth]. Haemorrhage of the cerebral or spinal membrane,

meninx (me'ninks) [Gr., membrane]. (pl. meninges) [NA] Any membrane, but esp. one of the coverings of the brain or spinal cord.

Menisci (men-is'e). Pl. of meniscus.

meniscitis (men"i-si'tis) [Gr. meniskos, crescent, + itis, inflammation]. Inflamed condition of an interarticular cartilage, esp. the semilunar cartilage of the knee joint.

meniscus (men-is'kus) [Gr. meniskos, crescent]. (pl. menisci) 1. Concavoconvex lens. 2. Interarticular fibrocartilage of crescent shape, found in certain joints, esp. the lateral and medial menisci (semilunar cartilages) of the knee joint. 3. The curved upper surface of a liquid in a container. The surface is convex if the liquid does not wet the container and concave if it does.
m. articularis. [NA] Crescent-shaped interarticular fibrocartilage found in certain synovial joints.

motile (mo'til) [L. motilis, moving]. Able to move spontaneously.

motility (mo-til'i-te). Power to move spontaneously.

motion (mo'shin) [L. motio, movement]. 1. A change of place or position; movement.
m., active. Movement caused by the patients own intention.
m., passive. Movement as the result of the attendant's causing the part to be moved.

motor neuron. 1. A neuron that innervates muscle tissue. 2. A neuron that carries impulses initiating muscle contraction.

motor neuron disease. One of several types of disease of the motor neurons: progressive muscle atrophy, progressive bulbar palsy, and amyotrophic lateral sclerosis. These diseases are characterized by degeneration of anterior horn cells of the spinal cord, the motor cranial nerve nuclei, and the pyramidal tracts. They occur principally in males. In the U.S., amyotrophic lateral sclerosis is known to the laity as Lou Gehrig's disease. He was a well-known athlete whose baseball career and life were prematurely, ended as a result of this disease. SEE: amyoitrophic lateral sclerosis.

motor points. Points where the motor nerve enters the muscle and where visible contraction can be elicited with a minimal amount of stimulation.

motor sense. The kinesthetic sense.

motor unit. A single motor neuron and the muscle fibers its branches innervate.

movement [L. mouere, to move]. Act of passing from place to place or changing position of the body or its parts.
m., active. Voluntary movement accomplished without external assistance.
m., angular. Voluntary muscular movement resulting in change in the angle between the involved bones.
m., associated. Involuntary movement of part occurring coincident with and subsequent to the movement of another part.
m., autonomic. Spontaneous, involuntary movement independent of external stimulation.
m.passive, movement of the body or a part due to outside forces.
**

mucopolysaccharidosis. ABBR: MPS. A group of inherited disorders characterized by a deficiency of enzymes that are essential for the degradation of the mucopolysaccharides heparan sulfate, dermatan sulfate, and keratan sulfate. These chemicals are excreted in excess quantities in the urine; and they usually accumulate in reticuloendethelial cells, endothelial cells, intimal smooth muscle cells, and fibroblasts throughout the body. Clinically, these disorders include some or all of the following: coarse facies, corneal clouding, hepatosplenomegaly, joint stiffness, hernias, skeletal dysplasia, and mental deficiency. The changes are not usually apparent at birth; but the inherited defect can be diagnosed prior to birth by culturing amniotic fluid cells and testing them for specific enzyme activity. The test may yield either false-positive or false-negative results. After birth the conditions may be diagnosed by testing cultured skin fibroblasts for specific enzymes.

multiple sclerosis. ABBR: MS. An inflammatory disease of the central nervous system in which infiltrating lymphocytes, predominantly T cells and macrophagees degrade the myelin sheath of nerves. It is suspected that the cause is an autoimmune disease somehow linked to a viral infection. The symptoms were once thought to develop gradually, but this is not necessarily true. In about 40% of cases the onset may occur in less than a few hours. The disease is rare in children; and, in about two-thirds of cases, it begins between the ages 20 and 40. The prevalence is less than one in 100,000 in the tropics; 6 to 14 in 100,000 in southern Europe and the southern U.S.; 30 to 80 in100,000 in Canada, northern Europe and the northern U.S. Blacks are at less risc than whites. SYM: At onset and in about one-half the patients, the symptoms and signs are weakness or numbness or both in one or more limbs; later, the tendon reflexes become hyperactive. In about one-quarter of patients, the initial manifestation is retrobulbar or optic neuritis. Other clinical findings at onset include unsteady gait, diplopia, vertigo, vomiting, and difficulty urinating. Nystagmus may be present. In the established stage of the disease, various clinical syndromes are present. They may be mostly due to optic nerve, brain stem, cerebellar, and spinal cord involvement or combinations of these. At one time, euphoria was thought to be a frequent finding, but emotional disturbances, including depression, irritability, and being short tempered, are not unusual. Clinically, MS is of the exacerbating-remitting type in which episodes of neurologic dysfunctionion are followed by recovery; or the chronic progressive type in which there is a steady progression of neurologic dysfunction. The duration of the disease is variable; some patients die a few months after onset; The average duration is more than 30 years. As many as one-third of surviving patients may still be working at the end of 25 years, two thirds will be ambulating.

muscle (mus'el) [L. musculus]. A type of tissue composed of contractile cells or fibers that effects movement of an organ or part of the body. The outstanding characteristic of muscular tissue is its ability to shorten or contract. It also possesses the properties of irritability, conductivity, and elasticity. Muscle tissue possesses little intercellular material, hence its cells or fibers lie close together.
TYPES: Three types of muscle differentiated on basis of histologic structure occur in the body, namely, smooth, striated, and cardiac.
Smooth, Nonstriated: Cells are fusiform or spindle-shaped, each containing a central nucleus. Cells usually arranged in sheets or layers but may occur as isolated units in connective tissue. Called involuntary because they are not under conscious control. Found principally in the internal organs, esp. digestive tract, respiratory passages, urinary and genital ducts, urinary bladder and gallbladder, and walls of blood vessels. Smooth muscle lacks the cross striations characteristic of other types of muscle.
Striated, Skeletal: The cytoplasm (sarcoplasm) contains numerous myofibrillae. The cytoplasmic cell membrane is called the sarcolemma. Muscle fibers are grouped into bundles called fasciculi, each of which is surrounded by a sheath or connective tissue called perimysium. The fibers within a fasciculus are surrounded by and held together by delicate reticular fibrils forming the endomysium. Striated muscle is found in all skeletal muscles, and movement is under conscious control. It also occurs in the tongue, pharynx, and upper portion of esophagus.
Cardiac: Fibers branch and anastomose, forming a continuous network or syncytium. At intervals, prominent bands or intercalated disks cross the fibers. Certain fibers, called Purkinje fibers, form the impulse-conducting system of the heart.
ANAT: A contractile organ consisting of muscle tissue, which effects movements of parts of the body, esp. a structure composed of striated muscle and attached to a part of the skeleton. A typical muscle consists of a central fleshy portion or belly and its attachments. The head is attached to a fixed structure termed the origin; the other end is attached to a movable part called the insertion. Some muscles are spindle-shaped; others form flat sheets or bands. Muscles may be attached directly to the periosteum of bones, or they may be attached by means of tough cords of connective tissue (tendons) or broad flat sheets (aponeuroses). The connective tissue enclosing a muscle is called epimysium; it is continuous with the deep fascia.
BLOOD SUPPLY: Obtained from small blood vessels that enter the muscular tissue and subdivide into capillaries that permeate throughout.
NERVE SUPPLY: Voluntary: From branches of' the peripheral cerebrospinal nervous system. It is because of this that the skeletal muscles are under conscious control. Involuntary: Smooth and cardiac receive their nerve supply from autonomic nervous system and function involuntarily without conscious control.
m., abductor. Muscle that draws away from the midline,
m., adductor. Muscle that draws toward the midline.
m., antagonistic. Muscle that counteracts the action of another muscle.
m. -s, antigravity. Muscles that pull against the constant force of gravity to maintain posture.
m., appendicular. One of the skeletal muscles of the limbs.
m., articular. Muscle attached to capsule of a joint
m., axial. A skeletal muscle of the head or trunk.
m., bipennate. Muscle in which the fibers converge toward a central tendon on both sides,
m., extensor. Muscle that extends a part.
m., extrinsic. Muscle whose origin lies outside the part moved.
m., fixation. Muscle that acts to steady a part in order that more precise movements in a related structure may be accomplished.
m., flexor. Muscle that bends a part.
m., fusiform. Muscle resembling a spindle.
m., intrinsic, Muscle that has both its origin and insertion within a structure. as intrinsic muscles of the tongue, eye, or limb.
m., involuntary. Muscle not under conscious control; mainly smooth muscle. m., multipennate. Muscle with several tendons of origin and several tendons of insertion in which fibers pass obliquely from a tendon of origin to a tendon of insertion on each side.
m., nonstriated.
m., smooth.
m., postaxial. Muscle on the posterior or dorsal aspect of a limb.
m., preaxial Muscle on the anterior or ventral aspect of a limb.
m., skeletal, Muscle that is connected with a bone; mainly striated.
m., somatic. Muscle derived from mesodermal somites. includes most skeletal muscle.
m., striated. Muscle fibers that possess alternate light and dark bands or striations; mainly voluntary and comprise skeletal muscles,
m,'s, synergistic. Muscles aiding one another in function
m., unipennate. Muscle whose fibers converge on only one side of a tendon.
m., unstriated. Muscle without markings: mainly involuntary.
m., voluntary. Muscle whose action is controlled by will, except for the cardiac muscle. all striated muscles are voluntary.

muscle compartment syndrome. The product of nerve damage, ischemia, edema, and muscle contractures by compression of nerves, vessels. and tissues within a fascial compartment SEE: carpal tunnel syndrome. ** Painful involuntary contractions of muscles, may be due to ischemia of the muscle(s), dehydration, or electrolyte imbalance.

muscle fiber types, fast twitch and slow twitch. Types of fibers found in skeletal muscle. The fast twitch fibers are more abundant in athletes whose sport necessitates fast action as compared to endurance, i.e., jumping, sprinting, and throwing. The slow twitch fibers are concentrated in the skeletal muscles of athletes who perform in endurance events such as long-distance running.

muscle soreness. The onset of muscular discomfort within 24 to 48 hours following unaccustomed exercise or of exercise of greater intensity than usual. muscular contractions, graduated. Accomplished by use of electric current of varying strength and duration. Used in muscles with an intact nerve supply when muscles are atonic, wasted away, or when voluntary exercise is not feasible; and in denervated muscles as in cases following nerve injury or poliomyelitis.

muscular dystrophy. Wasting away and atrophy of muscles. SEE: dystrophy, progressive muscular.

myasthenia (mi-as-the'ne-a) [Gr. mys, muscle, + astheneia, weakness]. Muscular weakness. m., angiosclerotic. Vascular changes producing excessive muscular fatigue.
m. cordis. Weakness of the heart muscle.
m. gravis. A disease characterized by great muscular weakness (without atrophy) and progressive fatigability. Power is restored with rest. Marked improvement in strength following administration of anticholinesterase drugs. It is due to a functional abnormality, lack of acetylcholine or excess of cholinesterase at the myoneural junction, in which nerve impulses fail to induce normal muscle contractions.
SYM: Abnormal fatigability and weakness of muscles. Muscles of the face and neck primarily involved, those of the trunk and extremities secondarily. Onset gradual; symptoms worse in the evening. Patient complains of difficulty in chewing, swallowing, and talking. Expressionless facies and ptosis usually present. ETIOL: An autoimmune mechanism causes the disease. More common in females if onset is at an age less than 40. Occurs most frequently between ages of 20 and 50. TREAT: Restricted activity; complete rest in severe cases. Soft or liquid diet; tube feedings sometimes essential. Physostigmine and neostigmine given intramuscularly or orally are effective. Potassium chloride, ephedrine, and guanidine are also used as adjuvants of pyridostigmine bromide (Mestinon), the drug of choice. If a thymoma is present, the thymus is removed. Corticosteroids are effective in-patients who have not been aided by thymectomy. In severe cases, use of plasmapheresis may be life-saving. Immunosuppression is a useful adjunct to alternate-day therapy with corticosteroids. PROG: Some cases mild; others rapidly fatal, death resulting from respiratory failure. Course is variable. Prolonged remissions may occur.

myasthenic. Marked by muscular weakness.

myatonia (mi-a-to'ne-a). Deficiency or loss of muscular tone.
m. congenita. A noninherited but sometimes familial disease characterized by absence of muscular development, with the lower extremities being the first involved. It is seen shortly after birth. SYN: amyotonia congenita; Oppenheim's disease.

myelanalosis (mi"el-an"al-o'sis) [" -+analosi;, wasting]. Gradual wasting of the spinal cord.

myelapoplexy (mi"el-ap'o-pleks-e) [" + apoplexia, stroke]. Hemorrhagic effusion into the spinal cord.

myelasthenia (mi"e1-as-the'ne-a) [Gr. myelos, marrow, + astheneia, weakness]. Spinal exhaustion; neurasthenia arising from disease of the spinal cord.

myelatelia (mi"el-a-te'le-a) [" + atelela, imperfection]. Defective development of the spinal cord.

myelatrophy (mi-e1-at'ro-fe) [" + atrophia, atrophy]. Wasting of the spinal cord.

myelauxe (mi-e1-awks'e) [" -i- auxe, increase]. Abnormal enlargement oŁ spinal cord.