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Medical Dictionary - Dictionary of Medicine and Human Biology


Medical Dictionary


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retropharynx (re′tro-far′ingks)
The posterior part of the pharynx.

retroplacental (re′tro-pla-sen′tal)
Behind the placenta.

retroplasia (ret-ro-pla′ze-a)
That state of cell or tissue in which activity is decreased below that considered normal; associated with retrogressive changes ( e.g., injury, degeneration, death, necrosis). [retro- + G. plasis, a molding]

retroposed (re′tro-pozd)
Denoting retroposition. [retro- + L. pono, pp. positus, to place]

retroposition (re′tro-po-zish′un)
Simple backward displacement of a structure or organ, as the uterus, without inclination, bending, retroversion, or retroflexion. [retro- + L. positio, a placing]

retroposon (re-tro-pos′on)
A transposition of sequences in a DNA that does not originate in the DNA but rather in an mRNA that is transcribed back into the genomic DNA by reverse transcription. [retro- + L. pono, pp. positum, to place, + -on]

retropubic (re-tro-pu′bik)
Posterior to the pubic bone.

retropulsion (re-tro-pul′shun)
1. An involuntary backward walking or running, occurring in patients with the parkinsonian syndrome. 2. A pushing back of any part. [retro- + L. pulsio, a pushing, fr. pello, pp. pulsus, beat, drive]

retrospection (re-tro-spek′shun)
The act or process of surveying and reviewing the past. [retro- + L. specto, pp. spectatus, to look at]

retrospective (re-tro-spek′tiv)
Relating to retrospection.

retrospondylolisthesis (re′tro-spon′di-lo-lis-the′sis)
Slipping posteriorly of the body of a vertebra, bringing it out of line with the adjacent vertebrae. [retro- + G. spondylos, vertebra, + olisthesis, a slipping]

retrosternal (re′tro-ster′nal)
Posterior to the sternum.

retrosteroid (re-tro-ster′oyd, -ster′oyd)
A term sometimes used to designate a steroid in which the orientations of the substituents at carbons-9 and -10 are the opposite of those of the reference or “parent” compound.

retrotarsal (re′tro-tar′sal)
Posterior to the tarsus, or edge of the eyelid.

retrouterine (re′tro-u′ter-in)
Posterior to the uterus.

retroversioflexion (re-tro-ver′se-o-flek′shun, -ver′zho-)
Combined retroversion and retroflexion of the uterus.

retroversion (re-tro-ver′zhun)
1. A turning backward, as of the uterus. 2. Condition in which the teeth are located in a more posterior position than is normal. [retro- + L. verto, pp. versus, to turn]

retroverted (re′tro-ver-ted)
Denoting retroversion.

Retroviridae (re-tro-vir′i-de)
A family of RNA viruses 80–100 nm in diameter, enveloped, and containing two identical molecules of positive sense, single-stranded RNA, molecular weight 3–6 × 106; genomic RNA serves as a template for the synthesis of a complementary DNA, which may be integrated into the host DNA. There are currently 7 genera: Mammalian type B retroviruses, Mammalian type C retroviruses, Avian type C retroviruses, Type D retroviruses, BLV-HTLV retroviruses, Lentivirus, and Spumovirus.

retrovirus (re′tro-vi′rus)
Any virus of the family Retroviridae.Retroviruses are potent disease agents, but they have also served as invaluable research tools in molecular biology. In 1979, the molecular biologist Richard Mulligan used a genetically altered r. to trigger the production of hemoglobin in vitro by monkey kidney cells. His technique for using retroviruses to import alien genes into cells has been widely adopted. Medical researchers have also explored retroviral transport as a means of gene therapy. However, evidence suggesting that retroviruses may play a role in carcinogenesis raises questions as to the safety of their use in gene therapy. See oncogene.

retrusion (re-troo′zhun)
1. Retraction of the mandible from any given point. 2. The backward movement of the mandible. [L. retrudo, pp. -trusus, to push back]

Rett
Andreas, 20th century Austrian pediatrician. See R. syndrome.

return
venous r. the blood returning to the heart via the great veins and coronary sinus.

Retzius
Magnus G., Swedish anatomist and anthropologist, 1842–1919. See R. striae, under stria, lines of R., under line, foramen of R., calcification lines of R., under line, foramen of Key-R., sheath of Key and R..

Retzius
Anders A., Swedish anatomist and anthropologist, 1796–1860. See R. cavity, cavum retzii, R. fibers, under fiber, R. gyrus, R. ligament, R. space, retroperitoneal veins, under vein.

reunient (re-u′ne-ent)
Connecting; denoting the ductus reuniens. [L. re-, again, + unio, pp. unitus, to unite]

Reuss
August von, Austrian ophthalmologist, 1841–1924. See R. formula, R. test.

revaccination (re′vak-si-na′shun)
Vaccination of an individual previously successfully vaccinated.

revascularization (re-vas′ku-lar-i-za′shun)
Reestablishment of blood supply to a part.

reverberation (re′ver-be-ra′shun)
Multiple echoes or reflections; in ultrasonography, an artifactual image caused by delay of an echo that has been reflected back and forward again before returning to the transducer.

Reverdin
Jacques L., Swiss surgeon, 1842–1929. See R. graft.

reversal (re-ver′sal)
1. A turning or changing to the opposite direction, as of a process, disease, symptom, or state. 2. The changing of a dark line or a bright one of the spectrum into its opposite. 3. Denoting the difficulty of some persons in distinguishing the lowercase printed or written letter p from q or g, b from d, or s from z. 4. In psychoanalysis, the change of an instinct or affect into its opposite, as from love into hate. [L. reverto, pp. -versus, to turn back or about] adrenaline r. SYN: epinephrine r.. epinephrine r. the fall in blood pressure produced by epinephrine when given following blockage of α-adrenergic receptors by an appropriate drug such as phenoxybenzamine; the vasodilation reflects the ability of epinephrine to activate β-adrenergic receptors that, in vascular smooth muscle, are inhibitory; in the absence of α-receptor blockade, the β-receptor activation by epinephrine is masked by its predominant action on vascular α-receptors, which causes vasoconstriction. SYN: adrenaline r.. narcotic r. the use of narcotic antagonists, such as naloxone, to terminate the action of narcotics. pressure r. cessation of anesthesia by hyperbaric pressure; of major importance in understanding the mode of action of anesthetics. sex r. SYN: sex reassignment.

reversible (re-ver′si-bl)
Capable of reversal; said of diseases or chemical reactions.

reversion (re-ver′zhun)
1. The manifestation in an individual of certain characteristics, peculiar to a remote ancestor, which have been suppressed during one or more of the intermediate generations. 2. The return to the original phenotype, either by reinstatement of the original genotype (true r.) or by a mutation at a site different from that of the first mutation, which cancels the effect of the first mutation (suppressor mutation). [L. reversio (see reversal)]

revertant (re-ver′tant)
In microbial genetics, a mutant that has reverted to its former genotype (true reversion) or to the original phenotype by means of a suppressor mutation. [L. revertans, pros.p. of reverto, to turn back]

review


Revilliod
Léon, Swiss physician, 1835–1919. See R. sign.

revivescence (re-vi-ves′ens)
SYN: revivification (1) . [L. re-vivesco, to come to life again, fr. vivo, to live]

revivification (re-viv′i-fi-ka′shun)
1. Renewal of life and strength. SYN: revivescence. 2. Refreshening the edges of a wound by paring or scraping to promote healing. SYN: vivification. [L. re-, again, + vivo, to live, + facio, to make]

revulsion (re-vul′shun)
SYN: derivation (1) . [L. revulsio, act of pulling away, fr. revello, pp. -vulsus, to pluck or pull away]

reward (re-ward′)
SYN: reinforcer.

rewarming (re-warm′ing)
Application of heat to correct hypothermia.

Rexed
Bror A., Swedish physician, scientist, and public servant, *1914. See lamina of R..

Reye
Ralph Douglas Kenneth, 20th century Australian pathologist. See R. syndrome.

Reymond
See Du Bois-R..

Reynolds
Osborne, English physicist, 1842–1912. See R. number.

RF
Abbreviation for releasing factors; rheumatoid factors, under factor; replicative form; reticular formation.

RFA
Abbreviation for right frontoanterior position.

RFLP
Abbreviation for restriction fragment length polymorphism.

RFP
Abbreviation for right frontoposterior position.

RFT
Abbreviation for right frontotransverse position.

RH
Abbreviation for releasing hormone.

Rh
1. Symbol for rhodium. 2. See R. blood group, Blood Groups appendix.

Rha
Abbreviation for l-rhamnose.

rhabarberone (ra-bar′ber-on)
SYN: aloe-emodin.

rhabd-
See rhabdo-.

rhabditiform
See r. larva.

Rhabditis-like
See rhabditiform larva.

rhabdo-, rhabd-
Rod; rod-shaped (rhabdoid). [G. rhabdos]

rhabdocyte (rab′do-sit)
Rarely used term for band cell or metamyelocyte. [rhabdo- + G. kytos, cell]

rhabdoid (rab′doyd)
Rod-shaped. [rhabdo- + G. eidos, resemblance]

rhabdomyoblast (rab-do-mi′o-blast)
Large round, spindle-shaped, or strap-shaped cells with deeply eosinophilic fibrillar cytoplasm that may show cross striations; found in some rhabdomyosarcomas. [rhabdo- + G. mys, muscle, + blastos, germ]

rhabdomyolysis (rab′do-mi-ol′i-sis)
An acute, fulminating, potentially fatal disease of skeletal muscle that entails destruction of muscle, as evidenced by myoglobinemia and myoglobinuria. [rhabdo- + G. mys, muscle, + lysis, loosening] acute recurrent r. [MIM*268200] repeated paroxysmal attacks of muscle pain and weakness followed by passage of dark red-brown urine, often precipitated by intercurrent illness and diagnosed by demonstration of myoglobin in the urine; it is attributed to abnormal phosphorylase activity in skeletal muscle, but there may be more than one biologic type; probably autosomal recessive inheritance. In some cases, at least, there is deficiency of carnitine palmitoyl transferase. SYN: familial paroxysmal r.. exertional r. r. produced in susceptible individuals by muscular exercise. familial paroxysmal r. SYN: acute recurrent r.. idiopathic paroxysmal r. SYN: myoglobinuria.

rhabdomyoma (rab′do-mi-o′ma)
A benign neoplasm derived from striated muscle, occurring in the heart in children, probably as a hamartomatous process. [rhabdo- + G. mys, muscle, + -oma, tumor]

rhabdomyosarcoma (rab′do-mi-o-sar-ko′ma)
A malignant neoplasm derived from skeletal (striated) muscle, occurring in children or, less commonly, in adults; classified as embryonal alveolar (composed of loose aggregates of small round cells) or pleomorphic (containing rhabdomyoblasts). SYN: rhabdosarcoma. [rhabdo- + G. mys, muscle, + sarkoma, sarcoma] embryonal r. malignant neoplasm occurring in children, consisting of loose, spindle-celled tissue with rare cross-striations, and arising in many parts of the body in addition to skeletal muscles.

rhabdophobia (rab-do-fo′be-a)
Morbid fear of a rod (or switch) as an instrument of punishment. [rhabdo- + G. phobos, fear]

rhabdosarcoma (rab′do-sar-ko′ma)
SYN: rhabdomyosarcoma.

rhabdosphincter (rab′do-sfingk′ter)
A sphincter made up of striated musculature. SYN: striated muscular sphincter. [rhabdo- + G. sphinkter, sphincter]

Rhabdoviridae (rab′do-vir′i-de)
A family of rod- or bullet-shaped viruses of vertebrates, insects, and plants, including rabiesvirus and vesicular stomatitis virus (of cattle). Virions (100–430 by 45–100 nm), formed by budding from surface membranes of cells, are enveloped and ether sensitive, with surface spikes 5–10 nm long; nucleocapsids contain negative sense single-stranded RNA (MW ∼4.4 × 106) and are of helical symmetry. There are five genera: Vesiculovirus, Lyssavirus, Ephemerovirus, Nucleorhabdovirus, and Cytorhabdovirus.

rhabdovirus (rab′do-vi′rus)
Any virus of the family Rhabdoviridae.

rhachi-
For words so beginning, see rachi-.

Rhadinovirus (rad-en′o-vi-rus)
A herpesvirus genus, subfamily Gammaherpesvirinae, associated with Kaposi sarcoma.

rhagades (rag′a-dez)
Chaps, cracks, or fissures occurring at mucocutaneous junctions; seen in vitamin deficiency diseases and in congenital syphilis. [G. rhagas, pl. r., a crack]




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