| major histocompatibility antigen | <immunology> A set of plasmalemmal glycoprotein antigens involved in rapid (e.g. 7 days in the mouse) graft rejection and other immune phenomena. The minor histocompatibility antigens are involved in much slower rejection phenomena. The major antigens show remarkable polymorphism and occur as Class I and Class II types in mammals, birds may have a Class III molecule as well. See: histocompatibility antigens, MHC restriction. (18 Nov 1997) |
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| major histocompatibility complex | The set of gene loci specifying major histocompatibility antigens, for example HLA in man, H 2 in mice, RLA in rabbits, RT 1 in rats, DLA in dogs, SLA in pigs, etc. Acronym: MHC (18 Nov 1997) |
| major hypnosis | A state of extreme suggestibility in hypnosis in which the subject is insensible to all outside impressions except the commands of the hypnotist. (05 Mar 2000) |
| major hysteria | A syndrome, now rarely seen, described by Charcot and characterised by a first stage of aura, a second stage of epileptoid convulsions, a third stage of tonic and clonic spasms, a fourth stage of dramatic behaviour, and a fifth stage of delirium; the entire attack may last from a few minutes to half an hour. Sometimes used as a synonym for hysteroepilepsy. (05 Mar 2000) |
| major intrinsic protein | <protein> Family of structurally related proteins with 6 transmembrane segments, associated with gap junctions or vacuoles. MIP is found in lens fibre gap junctions. Other members: nodulin 26 (soybean), tonoplast intrinsic protein (TIP) found in plant storage vacuoles, Drosophila neurogenic protein big brain. (18 Nov 1997) |
| major mood disorder | See: bipolar disorder, affective psychosis, endogenous depression, dysthymia. (05 Mar 2000) |
| major motor seizure | A grand mal seizure or other convulsive seizure. (05 Mar 2000) |
| major operation | An extensive, relatively difficult surgical procedure involving vital organs and/or in itself hazardous to life. (05 Mar 2000) |
| major salivary glands | A category of salivary gland's that includes the three largest gland's of the oral cavity that also secrete most of the saliva: the parotid, submandibular, and sublingual gland's. (05 Mar 2000) |
| major source | A source that emits, or has the potential to emit, a pollutant regulated under the Clean Air act in excess of a specified rate in a nonattainment area. (05 Dec 1998) |
| major sublingual duct | The duct that drains the anterior portion of the sublingual gland; it opens at the sublingual papilla. Synonym: ductus sublingualis major, Bartholin's duct. (05 Mar 2000) |
| major surgery | See: major operation. (05 Mar 2000) |
| major tranquilliser |
| pelvis justo major | A symmetrical pelvis with greater than normal measurements in all diameters. (05 Mar 2000) |
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| pelvis major | The expanded portion of the pelvis above the brim. Synonym: pelvis major, false pelvis, large pelvis, pelvis spuria. (05 Mar 2000) |
| rhomboideus major | <anatomy, muscle> Origin, spinous processes and corresponding supraspinous ligaments of first four thoracic vertebrae; insertion, medial border of scapula below spine; action, draws scapula toward vertebral column; nerve supply, dorsal of scapula nerve. Synonym: musculus rhomboideus major, greater rhomboid muscle. (05 Mar 2000) |
| pestis major | <microbiology> This rare bacterial infection due to Yersinia pestis. It can cause painful, enlarged lymph nodes, fever, headache and prostration 2-7 days after a flea bite. May also cause pneumonia and sepsis. Transmitted in rodents and humans via an infected flea bite. The incubation period is 2-10 days. Yersinia infection is now rare in Western countries. Third world countries (for example India) can have epidemics of Yersinia. Treatment with antibiotics is necessary or most individuals will die. Even with antibiotic treatment the death rate is 5%. (15 Nov 1997) |
| chorea major | A spasmodic attack occurring in patients with conversion hysteria. (05 Mar 2000) |
| Phlebotomus major | A vector of kala azar in the Mediterranean region. (05 Mar 2000) |
| circulus arteriosus iridis major | An arterial circle at the ciliary border of the iris. Synonym: circulus arteriosus iridis major. (05 Mar 2000) |
| clavicular part of pectoralis major muscle | pars clavicularis musculi pectoralis majoris, clavicular head of pectoralis major |
| musculus helicis major | <anatomy> A narrow band of muscular fibres on the anterior border of the helix of the auricle arising from the spine and inserted at the point where the helix becomes transverse. Synonym: musculus helicis major, large muscle of helix. (05 Mar 2000) |
| musculus pectoralis major | <anatomy, muscle> Origin, clavicular part (pars clavicularis), medial half of clavicle; sternocostal part (pars sternocostalis), anterior surface of manubrium and body of sternum and cartilages of first to sixth ribs; abdominal part (pars abdominalis), aponeurosis of external oblique; insertion, crest of greater tubercle of humerus; action, adducts and medially rotates arm; nerve supply, anterior thoracic. Synonym: musculus pectoralis major, greater pectoral muscle. (05 Mar 2000) |
| musculus psoas major | <anatomy, muscle> Origin, bodies of vertebrae and intervertebral disks from the twelfth thoracic to the fifth lumbar, and transverse processes of the lumbar vertebrae; insertion, forms a common insertion with iliacus muscle into lesser trochanter of femur; action, flexes hip joint; nerve supply, lumbar plexus (ventral rami of first, second and usually third lumbar spinal nerves). Synonym: musculus psoas major, greater psoas muscle. (05 Mar 2000) |
| musculus rectus capitis anticus major | <anatomy, muscle> Origin, anterior tubercles of transverse processes of third to sixth cervical vertebrae; insertion, basilar process of occipital bone; action, twists or flexes neck anteriorly; nerve supply, cervical plexus. Synonym: musculus longus capitis, long muscle of head, musculus rectus capitis anticus major. (05 Mar 2000) |
| musculus rectus capitis posterior major | <anatomy, muscle> Origin, spinous process of axis; insertion, middle of inferior nuchal line of occipital bone; action, rotates and draws head backward; nerve supply, dorsal branch of first cervical (suboccipital). See: suboccipital muscles. Synonym: musculus rectus capitis posterior major, greater posterior rectus muscle of head, musculus rectus capitis posticus major. (05 Mar 2000) |
| musculus rectus capitis posticus major | <anatomy, muscle> Origin, spinous process of axis; insertion, middle of inferior nuchal line of occipital bone; action, rotates and draws head backward; nerve supply, dorsal branch of first cervical (suboccipital). See: suboccipital muscles. Synonym: musculus rectus capitis posterior major, greater posterior rectus muscle of head, musculus rectus capitis posticus major. (05 Mar 2000) |
| musculus rhomboideus major | <anatomy, muscle> Origin, spinous processes and corresponding supraspinous ligaments of first four thoracic vertebrae; insertion, medial border of scapula below spine; action, draws scapula toward vertebral column; nerve supply, dorsal of scapula nerve. Synonym: musculus rhomboideus major, greater rhomboid muscle. (05 Mar 2000) |