transposition /trans·po·si·tion/ (trans″po-zish´un)
transposition [trans″po-zish´un]
1. displacement of a viscus to the opposite side.
2. the operation of carrying a tissue flap from one situation to another without severing its connection entirely until it is united at its new location.
3. the exchange of position of two atoms within a molecule.
transposition of great vessels a congenital cardiovascular malformation in which the position of the chief blood vessels of the heart is reversed. Life then depends on a crossflow of blood between the right and left sides of the heart, as through a ventricular septal defect.
trans·po·si·tion (tr ns p -z sh n)n. 1. Removal from one place to another. 2. The state of being transposed or of being on the wrong side of the body. 3. Transfer of a segment of DNA to a new position on the same or another chromosome, plasmid, or cell. |
transposition [trans″po-zish´un]
displacement to the opposite side; in genetics, the nonreciprocal insertion of material deleted from one chromosome into another, nonhomologous chromosome.
transposition of great vessels a congenital heart defect in which the position of the chief blood vessels of the heart is reversed, so that the aorta arises from the right ventricle instead of the left and the pulmonary artery emerges from the left ventricle rather than from the right. The result is that oxygen-poor blood returning from the systemic circulation to the right side of the heart gets pumped back into the general circulation instead of being transported to the lungs, and oxygen-rich blood flows aimlessly to and from the lungs. The condition may be corrected by surgery. 
Complete transposition of great arteries.
transposition
displacement to the opposite side; in genetics, the nonreciprocal insertion of material deleted from one chromosome into another, nonhomologous chromosome.
transposition of arterial trunks
see transposition of great vessels (below).
transposition of great vessels
a congenital heart defect, in which the position of the chief blood vessels of the heart is reversed. Called also transposition of arterial trunks.
ulnar styloid transposition
a surgical procedure for correction of growth deformity resulting from premature closure of the distal ulnar physis. The distal tip of the ulna is fused to the distal radial epiphysis.
transposition
1. The act of converting the prescription of an ophthalmic lens from a sphere with minus cylinder form to a sphere with plus cylinder form or vice versa. Example: −3 D sphere −2 D cylinder axis 180º transposes to −5 D sphere +2 D cylinder axis 90º.
2. A surgical procedure used to correct muscle paralysis. In this procedure, adjacent muscles are transferred (transposed) to the paralysed muscle, allowing for partial movement in the field of action of the paretic muscle. There are various procedures: one in which parts of the recti muscles are sutured together (the superior and inferior recti are disinserted and joined to the lateral rectus) to correct lateral rectus palsy and improve abduction (Hummelsheim's procedure or
transposition
Pediatrics A malposition of an organ or tissues that occurs during embryogenesis Psychiatry See Gender identity transposition Surgery Plastic surgery in which a flap of tissue is moved from one site to another and allowed
sufficient time to establish a new blood supply before severing the vascular connection with the donor site. See Sensory nerve transposition.
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