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Medical Dictionary - Dictionary of Medicine and Human Biology

Medical Dictionary


myomelanosis (mi′o-mela-no′sis)
Abnormal dark pigmentation of muscular tissue. SEE ALSO: melanosis. [myo- + G. melanosis, becoming black]

myomere (mi′o-mer)
SYN: myotome (4) . [myo- + G. meros, a part]

myometer (mi-om′e-ter)
An instrument for measuring the extent of a muscular contraction. [myo- + G. metron, measure]

myometrial (mi-o-me′tre-al)
Relating to the myometrium.

myometritis (mi′o-me-tri′tis)
Inflammation of the muscular wall of the uterus. [myo- + G. metra, uterus, + -itis, inflammation]

myometrium (mi′o-me′tre-um) [TA]
The muscular wall of the uterus. SYN: tunica muscularis uteri [TA] , muscular coat of uterus. [myo- + G. metra, uterus]

myomitochondrion, pl .myomitochondria (mi′o-mi′to-kon′dre-on, -dre-a)
A mitochondrion of a muscle fiber.

myomotomy (mi-o-mot′o-me)
Incision of a myoma. [myoma + G. tome, incision]

myon (mi′on)
An individual muscle unit. [G. mys, muscle]

myonecrosis (mi′o-ne-kro′sis)
Necrosis of muscle. clostridial m. SYN: gas gangrene.

myoneme (mi′o-nem)
1. A muscle fibril. 2. One of the contractile fibrils of certain protozoans; thought to function in an analogous fashion to metazoan muscle fibers. [myo- + G. nema, thread]

myoneural (mi-o-noo′ral)
Relating to both muscle and nerve; denoting specifically the synapse of the motor neuron with striated muscle fibers: m. junction or motor endplate. SEE ALSO: neuromuscular. [myo- + G. neuron, nerve]

myoneuroma (mi′o-noo-ro′ma)
A tumefaction consisting chiefly of abnormally proliferating Schwann cells, with variable numbers of muscle cells forming portions of the mass; myoneuromas are probably malformations, rather than true neoplasms. [myo- + G. neuron, nerve, + -oma, tumor]

myonymy (mi-on′i-me)
Nomenclature of the muscles. [myo- + G. onyma or onoma, name]

myopachynsis (mi′o-pa-kin′sis)
Muscular hypertrophy. [myo- + G. pachynsis, a thickening]

myopalmus (mi-o-pal′mus)
Muscle twitching. [myo- + G. palmos, a quivering]

myopathic (mi-o-path′ik)
Denoting a disorder involving muscular tissue.

myopathy (mi-op′a-the)
Any abnormal condition or disease of the muscular tissues; commonly designates a disorder involving skeletal muscle. [myo- + G. pathos, suffering] carcinomatous m. SYN: Lambert-Eaton syndrome. centronuclear m. slowly progressive generalized muscle weakness and atrophy beginning in childhood; on biopsy of skeletal muscle, the nuclei of most muscle fibers are seen to be located near the center of a small fiber (the normal position for a 10-week embryo) rather than at the periphery of the fiber; familial incidence. Autosomal dominant [MIM*160150] recessive [MIM*255200] and X-linked [310400] forms occur. The X-linked form is caused by mutation in the myotubular m. gene (MTM1) on Xq28. SYN: myotubular m.. distal m. m. affecting predominantly the distal portions of the limbs; onset is usually after age 40, with weakness and wasting of small muscles of the hands; The infantile form [MIM*160300] and the Swedish later-onset [MIM*160500] are autosomal dominant. There is a Japanese late-onset type [MIM*254130] that is recessive and is caused by mutation in the gene encoding dysferlin on 2p13. dysthyroid m. SYN: thyrotoxic m.. minicore-multicore m. an uncommon nonprogressive m. with early onset, proximal weakness, and hypotonia. Muscle fibers show focal defects of oxidative and myofibrillar adenosine triphosphatase enzymes with disorganization of myofibril ultrastructure. mitochondrial m. weakness and hypotonia of muscles, primarily those of the neck, shoulder, and pelvic girdles, with onset in infancy or childhood; on biopsy, giant, bizarre mitochondria are seen located between muscle fibrils just beneath the sarcolemma. There are autosomal dominant [MIM*251900] and recessive forms due to deletions or duplications of mitochondrial DNA, with one recessive form [MIM*252010] associated with a deficiency of complex 1 of the mitochondrial respiratory chain. myotubular m. SYN: centronuclear m.. nemaline m. congenital, nonprogressive muscle weakness most evident in the proximal muscles; named after the characteristic nemaline (threadlike) rods seen in the muscle cells composed of Z-band material. There are two forms, dominant [MIM*161800] caused by mutation in the tropomyosin-3 gene (TPM3) on 1q22–q23, and recessive [MIM*256030], that are clinically indistinguishable. SYN: rod m.. ocular m. SYN: chronic progressive external ophthalmoplegia. proximal myotonic m. (PROMM) an autosomal dominant, multisystem disorder, with onset in young adult life, characterized by proximal myotonia and weakness, muscle pain, baldness, cataracts, cardiac conduction disturbances, and testicular atrophy. In contrast to myotonic dystrophy, features of this disorder do not include facial weakness and ptosis, distal limb weakness and wasting, and trinucleotide repeat expansion at the gene loci for myotonic dystrophy. rod m. SYN: nemaline m.. thyrotoxic m. extreme muscular weakness in severe thyrotoxicosis affecting muscles of limbs and trunk as well as those used in speech and swallowing. SYN: dysthyroid m..

myopericarditis (mi′o-per-i-kar-di′tis)
Inflammation of the muscular wall of the heart and of the enveloping pericardium; also, perimyocarditis--choice of term determined by whether the principal involvement is pericardial or myocardial. [myo- + pericarditis]

myoperitonitis (mi′o-per-i-to-ni′tis)
Inflammation of the parietal peritoneum with myositis of the abdominal wall.

myophone (mi′o-fon)
An instrument to enable one to hear the murmur of muscular contractions. [myo- + G. phone, sound]

myophosphorylase (mi-o-fus-for′i-las)
Muscle phosphorylase

myopia (M) (mi-o′pe-a)
That optical condition in which only rays from a finite distance from the eye focus on the retina. SYN: near sight, nearsightedness, short sight, shortsightedness. [G. fr. myo, to shut, + ops, eye] axial m. m. due to elongation of the globe of the eye. curvature m. m. due to refractive errors resulting from excessive corneal curvature. degenerative m. SYN: pathologic m.. index m. m. arising from increased refractivity of the lens, as in nuclear sclerosis. malignant m. SYN: pathologic m.. night m. in dark adaptation the eye becomes more sensitive to shorter wavelengths (Purkinje shift), and visual acuity depends on parafoveal blue cones. Shorter wavelengths come into focus in front of the retina, and this chromatic aberration accounts for some of the relative m. that a normal eye experiences at night; much of the remainder is due to an increase in accommodative tone in the dark. pathologic m. progressive m. marked by fundus changes, posterior staphyloma, and subnormal corrected acuity. SYN: degenerative m., malignant m.. prematurity m. m. observed in infants of low birthweight or in association with retrolental fibroplasia. senile lenticular m. SYN: second sight. simple m. m. arising from failure of correlation of the refractive power of the anterior segment and the length of the eyeball. space m. a type of m. arising when no contour is imaged on the retina. transient m. m. observed in accommodative spasm secondary to iridocyclitis or ocular contusion.

myopic (M) (mi-op′ik, -o′pik)
Relating to or suffering from myopia.

myoplasm (mi′o-plazm)
The contractile portion of the muscle cell, as distinguished from the sarcoplasm. [myo- + G. plasma, a thing formed]

myoplastic (mi-o-plas′tik)
Relating to the plastic surgery of the muscles, or to the use of muscular tissue to correct a defect.

myoplasty (mi′o-plas-te)
Plastic surgery of muscular tissue. [myo- + G. plastos, formed]

myopolar (mi-o-po′lar)
Relating to muscular polarity, or to the portion of muscle between two electrodes.

myoprotein (mi-o-pro′ten)
Protein occurring in muscle.

myorrhaphy (mi-or′a-fe)
Suture of a muscle. [myo- + G. rhaphe, seam]

myorrhexis (mi-o-rek′sis)
Tearing of a muscle. [myo- + G. rhexis, a rupture]

myosalpingitis (mi′o-sal-pin-ji′tis)
Inflammation of the muscular tissue of the uterine tube. [myosalpinx + G. -itis inflammation]

myosalpinx (mi′o-sal′pingks)
The muscular tunic of the uterine tube. [myo- + salpinx]

myosarcoma (mi′o-sar-ko′ma)
A general term for a malignant neoplasm derived from muscular tissue. SEE ALSO: leiomyosarcoma, rhabdomyosarcoma.

myosclerosis (mi′o-skle-ro′sis)
Chronic myositis with hyperplasia of the interstitial connective tissue.

myoseptum (mi-o-sep′tum)
SYN: myocomma. [myo- + L. saeptum, a barrier]

myosin (mi′o-sin)
A globulin present in muscle that has an ATPase activity; in combination with actin, it forms actomyosin; m. forms the thick filaments in muscle. m. light chain kinase a calcium/calmodulin-dependent enzyme that phosphorylates the light chains of smooth muscle m. and initiates contraction. In skeletal muscle, phosphorylation modulates tension during contraction.

myosinogen (mi-o-sin′o-jen)
SYN: myogen.

myosinose (mi′o-si-nos)
A proteose formed by the partial hydrolysis of myosin.

myositic (mi-o-sit′ik)
Relating to myositis.

myositis (mi-o-si′tis)
Inflammation of a muscle. SYN: initis (2) . [myo- + G. -itis, inflammation] cervical m. posttraumatic neck syndrome. epidemic m., m. epidemica acuta SYN: epidemic pleurodynia. m. fibrosa induration of a muscle through an interstitial growth of fibrous tissue. SYN: interstitial m., myofascitis. infectious m. inflammation of the voluntary muscles, marked by swelling and pain, affecting usually the shoulders and arms, though almost the entire body may be involved. interstitial m. SYN: m. fibrosa. m. ossificans ossification or deposit of bone in muscle with fibrosis, causing pain and swelling in muscles. m. ossificans circumscripta local deposit of bone in a muscle, usually following prolonged trauma; e.g., riders' bone. m. ossificans progressiva a rare and frequently fatal mutation, beginning in early life, characterized by progressive ossification of the muscles; it is not strictly a m., but a noninflammatory ossification. proliferative m. a rapidly growing benign infiltrating fibrous nodule in skeletal muscle, containing characteristic giant cells resembling ganglion cells. m. purulenta tropica SYN: tropical pyomyositis. tropical m. SYN: tropical pyomyositis.

myospasm, myospasmus (mi′o-spazm, mi-o-spaz′mus)
Spasmodic muscular contraction. cervical m. posttraumatic neck syndrome.

myospherulosis (mi′o-sfer-oo-lo′sis)
A chronic granulomatous reaction to undetermined spherical structures frequently contained within a microscopic cyst; first reported in cystic lesions in skeletal muscle from eastern Africa and subsequently in nasal infections in the U.S. [myo- + L. sphaerula, small sphere, + G. -osis, condition]

myosthenometer (mi′o-sthe-nom′e-ter)
An instrument for measuring the power of muscle groups. [myo- + G. sthenos, strength, + metron, measure]

myostroma (mi-o-stro′ma)
The supporting connective tissue or framework of muscular tissue. [myo- + G. stroma, mattress]

myostromin (mi-o-stro′min)
A protein found in muscle stroma.

myotactic (mi-o-tak′tik)
Relating to the muscular sense. [myo- + L. tactus, a touching]

myotasis (mi-ot′a-sis)
Stretching of a muscle. [myo- + G. tasis, a stretching]

myotatic (mi-o-tat′ik)
Relating to myotasis.

myotenositis (mi′o-te-no-si′tis)
Inflammation of a muscle with its tendon. [myo- + G. tenon, tendon, + -itis, inflammation]

myotenotomy (mi′o-te-not′o-me)
Cutting through the principal tendon of a muscle, with division of the muscle itself in whole or in part. SYN: tenomyotomy, tenontomyotomy. [myo- + G. tenon, tendon, + tome, incision]

myothermic (mi-o-ther′mik)
Relating to the increased temperature in muscular tissue resulting from its contraction. [myo- + G. therme, heat]

myotome (mi′o-tom)
1. A knife for dividing muscle. 2. In embryos, that part of the somite that develops into skeletal muscle. SYN: muscle plate. 3. All muscles derived from one somite and innervated by one segmental spinal nerve. 4. In primitive vertebrates, the muscular part of a metamere. SYN: myomere. [myo- + G. tomos, a cut]

myotomy (mi-ot′o-me)
1. Anatomy or dissection of the muscles. 2. Surgical division of a muscle. [myo- + G. tome, excision] cricopharyngeal m. division of the cephalad portion of the cricopharyngeus muscle, usually for treatment of Zenker esophageal diverticulum. Heller m. distal esophagomyotomy, usually for the treatment of achalasia.

myotone (mi′o-ton)
SYN: myotony.

myotonia (mi-o-to′ne-a)
Delayed relaxation of a muscle after a strong contraction, or prolonged contraction after mechanical stimulation (as by percussion) or brief electrical stimulation; due to abnormality of the muscle membrane, specifically the ion channels. [myo- + G. tonos, tension, stretching] m. acquisita acquired m. following exposure to certain toxins. m. atrophica SYN: myotonic dystrophy. m. congenita [MIM*160800] an uncommon muscle disorder, with onset in infancy or early childhood, characterized by muscle hypertrophy, m., and a nonprogressive course; autosomal dominant inheritance; caused by mutations in the skeletal muscle chloride channel gene (CLCN1) on chromosome 7q. SYN: Thomsen disease. m. dystrophica SYN: myotonic dystrophy. m. neonatorum SYN: neonatal tetany.

myotonic (mi-o-ton′ik)
Pertaining to or exhibiting myotonia.

myotonoid (mi-ot′o-noyd)
Denoting a muscular reaction, naturally or electrically excited, characterized by slow contraction and, especially, slow relaxation. [myo- + G. tonos, tone, tension, + eidos, resemblance]

myotonus (mi-ot′o-nus)
A tonic spasm or temporary rigidity of a muscle or group of muscles. [myo- + G. tonos, tension, stretching]

myotony (mi-ot′o-ne)
Muscular tonus or tension. SYN: myotone. [myo- + G. tonos, tension]

myotrophy (mi-ot′ro-fe)
Nutrition of muscular tissue. [myo- + G. trophe, nourishment]

myotube (mi′o-toob)
A skeletal muscle fiber formed by the fusion of myoblasts during a developmental stage; a few myofibrils occur at the periphery, and the central core is occupied by nuclei and sarcoplasm so that the fiber has a tubular appearance.

myotubule (mi-o-t;oo′bool)
Former term for myotube.

Myoviridae (mi-o-vir′i-de)
A family of relatively large bacterial viruses with complex contractile tails, heads that are usually elongated but are isometric in some species, and a double-stranded DNA genome (MW 21–190 × 106). It includes the T-even phage group and probably other genera.

myrica (mir′i-ka)
The bark of M. cerifera (family Myricaceae); used in diarrhea and icterus, and externally in sore throat. SYN: bayberry bark.


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