|Medical Dictionary - Dictionary of Medicine and Human Biology|
In hospital psychiatry, intervention to prevent an excited or violent patient from doing harm to self or others; may involve the use of a camisole (straightjacket). [O. Fr. restrainte]
1. The process with which foreign DNA that has been introduced into a prokaryotic cell becomes ineffective. 2. A limitation. asymmetric fetal growth r. normal fetal head size as a result of preferential shunting of blood to brain, and decreased abdominal circumference from decreased adipose tissue and liver size; probably caused by placental insufficiency. fetal growth r. fetal weight ≤5th percentile for gestational age. SYN: intrauterine growth retardation. lactase r. an inherited trait in which there is low lactase activity and thus there is defective lactose intestinal metabolism. Cf.:lactase persistence. MHC r. T helper cells only recognize an antigen that is presented with class II major histocompatibility antigens whereas T cytotoxic cells usually only recognize a processed antigen in conjunction with class I major histocompatibility antigens. symmetric fetal growth r. proportional reduction in fetal head and body size, commonly constitutional or caused by an early intrauterine insult such as infection.
To perform resuscitation. [L. resuscito, to raise up again, revive]
Revival from potential or apparent death. [L. resuscitatio] cardiopulmonary r. (CPR) restoration of cardiac output and pulmonary ventilation following cardiac arrest and apnea, using artificial respiration and manual closed-chest compression or open-chest cardiac massage. mouth-to-mouth r. mouth-to-mouth respiration (q.v.) employed as part of emergency cardiopulmonary r..
Any type of clasp, attachment, or device used for the fixation or stabilization of a prosthesis; an appliance used to prevent the shifting of teeth following orthodontic treatment. continuous bar r. a metal bar, usually resting on lingual surfaces of teeth, to aid in their stabilization and to act as indirect retainers. SYN: continuous clasp. direct r. a clasp or attachment applied to an abutment tooth for the purpose of maintaining a removable appliance in position. extracoronal r. a r. that depends upon contact with the outer circumference of the crown of a tooth for its retentive qualities. Hawley r. a removable wire and acrylic palatal appliance used to retain or stabilize the teeth in their new position following orthodontic tooth movement; with modifications it can be used to move teeth as an active orthodontic appliance. SYN: Hawley appliance. indirect r. a part of a removable partial denture that assists the direct retainers in preventing occlusal displacement of the distal extension bases by functioning through lever action on the opposite side of the fulcrum line. intracoronal r. a r. that depends upon components placed within the crown portion of a tooth for its retentive qualities. matrix r. a mechanical device designed to hold a matrix around a tooth during restorative procedures, usually by engaging the ends of the matrix band and drawing the band tight. space r. SYN: space maintainer.
A mildly pejorative term, which is decreasing in usage, for a person who has mental retardation. [L. retardo, to delay, hinder]
Slowness or limitation of development. intrauterine growth r. SYN: fetal growth restriction. mental r. subaverage general intellectual functioning that originates during the developmental period and is associated with impairment in adaptive behavior. The American Association on Mental Deficiency lists eight medical classifications and five psychologic classifications; the latter five replace the three former classifications of moron, imbecile, and idiot. Mental r. classification requires assignment of an index for performance relative to a person's peers on two interrelated criteria: measured intelligence (IQ) and overall socioadaptive behavior (a judgmental rating of the individual's relative level of performance in school, at work, at home, and in the community). In general an IQ of 70 or below indicates mental r. (mild = 50/55–70; moderate = 35/40–50/55; severe = 20/25–35/40; profound = below 20/25); an IQ of 70–85 signifies borderline intellectual functioning. SYN: amentia (1) , mental deficiency, oligophrenia. psychomotor r. slowed psychic activity or motor activity, or both. viscoelastic r. a technique for the measurement of the molecular weight of large DNA molecules; the DNA is stretched by hydrodynamic shear forces and, when the molecules relax, the relaxation time is measured.
An agent used to slow the chemical hardening of gypsum, resins, or impression materials used in dentistry.
To make an involuntary effort to vomit. [A.S. hraecan, to hawk]
Gastric and esophageal movements of vomiting without expulsion of vomitus. SYN: dry vomiting, vomiturition.
rete, pl .retia (re′te; re′she-a, -te-a)
1. SYN: network (1) . 2. A structure composed of a fibrous network or mesh. [L. a net] r. acromiale arteriae thoracoacromialis [TA] SYN: acromial anastomosis of the thoracoacromial artery. r. arteriosum [TA] SYN: arterial plexus. r. articulare cubiti [TA] SYN: cubital anastomosis. r. articulare genus [TA] SYN: genicular anastomosis. r. calcaneum [TA] SYN: calcaneal anastomosis. r. canalis hypoglossi SYN: venous plexus of canal of hypoglossal nerve. r. carpale dorsale [TA] SYN: dorsal carpal arterial arch. r. carpi posterius SYN: dorsal carpal arterial arch. r. cutaneum corii the network of vessels parallel to the surface between the corium and the tela subcutanea. r. foraminis ovalis SYN: venous plexus of foramen ovale. Haller r. SYN: r. testis. r. halleri SYN: r. testis. r. malleolare laterale [TA] SYN: lateral malleolar network. r. malleolare mediale [TA] SYN: medial malleolar network. malpighian r. SYN: malpighian stratum. r. mirabile [TA] a vascular network interrupting the continuity of an artery or vein, such as occurs in the glomeruli of the kidney (arterial) or in the liver (venous). r. ovarii a transient network of cells in the developing ovary; homologous to the r. testis. r. patellare [TA] SYN: patellar anastomosis. r. subpapillare the network of vessels between the papillary and reticular strata of the corium. r. testis [TA] the network of canals at the termination of the straight tubules in the mediastinum testis. SYN: Haller r., r. halleri. r. vasculosum articulare [TA] SYN: articular vascular plexus. r. venosum dorsale manus [TA] SYN: dorsal venous network of hand. r. venosum dorsale pedis [TA] SYN: dorsal venous network of foot. r. venosum plantare [TA] SYN: plantar venous network.
1. The keeping in the body of what normally belongs there, especially the retaining of food and drink in the stomach. 2. The keeping in the body of what normally should be discharged, as urine or feces. 3. Retaining that which has been learned so that it can be utilized later as in recall, recognition, or, if r. is partial, relearning. SEE ALSO: memory. 4. Resistance to dislodgement. 5. In dentistry, a passive period following treatment when a patient is wearing an appliance or appliances to maintain or stabilize the teeth in the new position into which they have been moved. [L. retentio, a holding back] denture r. the means by which dentures are held in position in the mouth. direct r. r. obtained in a removable partial denture by the use of attachments or clasps that resist their removal from the abutment teeth. indirect r. r. obtained in a removable partial denture through the use of indirect retainers. partial denture r. the fixation of a removable partial denture by the use of clasps, indirect retainers, or precision attachments.
retia (re′she-a, -te-a)
Plural of rete. [L.]
Relating to a rete.
Plural of reticulum. [L.]
reticular, reticulated (re-tik′u-lar, -lat-ed)
Relating to a reticulum.
The presence or formation of a reticulum or network, such as that observed in the red blood cells during active regeneration of blood. Also used to describe a chest radiographic pattern. See reticulonodular pattern.
Name given to the chemical substance of reticular fibers, which once were thought to be distinct from collagen by reason of their distinctive structure and staining properties but are now regarded as type III collagen (with its associated proteoglygans and structural glycoproteins).
Reticulum; reticular. [L. reticulum, a small net, dim. of rete, a net]
A young red blood cell containing a basophilic cytoplasmic network precipitated by brilliant cresyl blue representing residual polyribosomes; such cells become more numerous during the process of active blood regeneration. SEE ALSO: erythroblast. SYN: reticulated corpuscle, skein cell. [reticulo- + G. kytos, cell]
Paucity of reticulocytes in the blood. SYN: reticulopenia. [reticulocyte + G. penia, poverty]
An increase in the number of circulating reticulocytes above the normal, which is less than 1% of the total number of red blood cells; it occurs during active blood regeneration (stimulation of red bone marrow) and in certain anemias, especially congenital hemolytic anemia. [reticulocyte + G. osis, condition]
Denoting or referring to reticuloendothelium. See r. system.
Obsolete term for a localized reticulosis, or neoplasm derived from reticuloendothelial tissue. [reticuloendothelium + G. -oma, tumor]
The cells making up the reticuloendothelial system. [reticulo- + endothelium]
A solitary skin nodule composed of glycolipid-containing multinucleated large histiocytes; multiple lesions sometimes occur in association with arthritis. [reticulo- + histiocytoma]
See reticulosis. multicentric r. a rare disease in which cutaneous papules composed of histiocytes containing glycolipids are associated with polyarthritis, often leading to shortening of the fingers.
1. Resembling a reticulosis. 2. A condition resembling reticulosis. actinic r. chronic pruritic erythema beginning on sun-exposed areas in elderly males, with marked thickening and ridging of exposed skin simulating lymphoma; there is infiltration by atypical CD8-positive T lymphocytes.
An increase in histiocytes, monocytes, or other reticuloendothelial elements. [reticulo- + G. -osis, condition] benign inoculation r. SYN: catscratch disease. leukemic r. obsolete term for monocytic leukemia. malignant midline r. obsolete term for polymorphic r. midline malignant r. granuloma SYN: lethal midline granuloma. pagetoid r. a usually solitary verrucous plaque on the extremities characterized histologically by predominantly epidermal infiltration of mononuclear cells resembling those found in mycosis fungoides; prognosis is good. SYN: Woringer-Kolopp disease. polymorphic r. a necrotizing lymphoproliferative lesion with a predilection for the upper respiratory tract; previously called lethal midline granuloma or malignant midline r.; treatment is irradiation.
Pertaining to the r. tract.
Production of lesions in the reticular formation. [reticulo- + G. tome, incision]
reticulum, pl .reticula (re-tik′u-lum, -la) [TA]
1. A fine network formed by cells, or formed of certain structures within cells or of connective tissue fibers between cells. 2. SYN: neuroglia. 3. The second compartment of the stomach of a ruminant, a comparatively small chamber communicating with the rumen; sometimes called the honeycomb because of the characteristic structure of its wall. [L. dim of rete, a net] agranular endoplasmic r. endoplasmic r. that is lacking in ribosomal granules; involved in synthesis of complex lipids and fatty acids, detoxification of drugs, carbohydrate synthesis, and sequestering of Ca++. SYN: smooth-surfaced endoplasmic r.. Ebner r. a network of nucleated cells in the seminiferous tubules. endoplasmic r. (ER) the network of cytoplasmic tubules or flattened sacs (cisternae) with (rough ER) or without (smooth ER) ribosomes on the surface of their membranes in eukaryotes. SYN: endomembrane system. Golgi internal r. SYN: Golgi apparatus. granular endoplasmic r. endoplasmic r. in which ribosomal granules are applied to the cytoplasmic surface of the cisternae; involved in the synthesis and secretion of protein via membrane-bound vesicles to the extracellular space. SYN: chromidial substance, ergastoplasm, rough-surfaced endoplasmic r.. Kölliker r. SYN: neuroglia. rough-surfaced endoplasmic r. SYN: granular endoplasmic r.. sarcoplasmic r. the endoplasmic r. of skeletal and cardiac muscle; the complex of vesicles, tubules, and cisternae forming a continuous structure around striated myofibrils, with a repetition of structure within each sarcomere. smooth-surfaced endoplasmic r. SYN: agranular endoplasmic r.. stellate r. a network of epithelial cells disposed in a fluid-filled compartment in the center of the enamel organ between the outer and inner enamel epithelium. trabecular r. SYN: trabecular tissue of sclera. r. trabeculare sclerae [TA] SYN: trabecular tissue of sclera. trans-Golgi r. that part of the Golgi apparatus that takes newly processed proteins and delivers them to secretory vesicles that will fuse with other biomembranes ( E.G., the plasma membrane).
Resembling a net or network. [L. rete, network]
retina (ret′i-na) [TA]
Grossly, the r. consists of three parts: optic part of r., ciliary part of r., and iridial part of r.. The optic part, the physiologic portion that receives the visual light rays, is further divided into two parts, the pigmented part (pigment epithelium) and the nervous part, which are arranged in the following layers: 1) pigmented layer; 2) layer of inner and outer segments (of rods and cones); 3) outer limiting layer (actually a row of junctional complexes); 4) outer nuclear layer; 5) outer plexiform layer; 6) inner nuclear layer; 7) inner plexiform layer; 8) ganglionic (cell) layer; 9) layer of nerve fibers; and 10) inner limiting layer. Layers 2–10 compose the neural layer. At the posterior pole of the visual axis is the macula, in the center of which is the fovea, the area of acute vision. Here layers 6–9 and blood vessels are absent, and only elongated cones are present. About 3 mm medial to the fovea is the optic disk, where axons of the ganglionic cells converge to form the optic nerve. The ciliary and iridial parts of the r. are forward prolongations of the pigmented layer and a layer of supporting columnar or epithelial cells over the ciliary body and the posterior surface of the iris, respectively. SYN: optomeninx. [Mediev. L. prob. fr. L. rete, a net] detached r. SYN: retinal detachment. flecked r. an r. exhibiting fundus flavimaculatus, hereditary drusen, or fundus albipunctatus. fleck r. of Kandori [MIM*228990] an autosomal recessive disorder of the retinal pigment epithelium characterized by retinal flecks and night blindness, occurring among Japanese. leopard r. SYN: tessellated fundus. shot-silk r. the appearance of numerous wavelike, glistening reflexes, like the shimmer of silk, observed sometimes in the r. of a young person. SYN: shot-silk phenomenon, shot-silk reflex. tigroid r. SYN: tessellated fundus.
retinaculum, gen. retinaculi, pl .retinacula (ret-i-nak′u-lum, -li, -la) [TA]
A frenum, or a retaining band or ligament. [L. a band, a halter, fr. retineo, to hold back] antebrachial flexor r. thickening of distal antebrachial fascia just proximal to radiocarpal (wrist) joint. Continuous with extensor r. at margins of forearm. This structure is distinct from the transverse carpal ligament, commonly called “the flexor r.,” which forms the roof of the carpal tunnel. SYN: flexor r. of forearm, palmar carpal ligament. r. of articular capsule of hip one of several longitudinal folds of the articular capsule of the hip joint reflected onto the femoral neck deep to which the retinacular branches of the medial femoral circumflex artery pass to reach the femoral head. SYN: r. capsulae articularis coxae, Weitbrecht fibers. r. capsulae articularis coxae SYN: r. of articular capsule of hip. caudal r. SYN: r. caudale. r. caudale [TA] fibrous bands, remnants of the notochord, that extend from the skin to the coccyx, forming the coccygeal foveola. SYN: caudal ligament, caudal r., ligamentum caudale. r. cutis [TA] SYN: skin ligaments, under ligament. r. cutis mammae suspensory ligaments of breast, under ligament. extensor r. [TA] a strong fibrous band formed as a thickening of the antebrachial deep fascia, stretching obliquely across the back of the wrist, attaching deeply to ridges on the dorsal aspect of the radius, triquetral, and pisiform bones, and binding down the extensor tendons of the fingers and thumb. SYN: r. musculorum extensorum [TA] , dorsal carpal ligament, ligamentum carpi dorsale. retinacula of extensor muscles See inferior extensor r., superior extensor r.. flexor r. [TA] a strong fibrous band crossing the front of the carpus and binding down the flexor tendons of the digits and the flexor carpi radialis tendon and the median nerve; in so doing it creates the carpal tunnel. SYN: r. musculorum flexorum [TA] , deep part of flexor r., ligamentum carpi transversum, ligamentum carpi volare, transverse carpal ligament, volar carpal ligament. flexor r. of forearm SYN: antebrachial flexor r.. flexor r. of lower limb [TA] a wide band passing from the medial malleolus to the medial and upper border of the calcaneus and to the plantar surface as far as the navicular bone; it holds in place the tendons of the tibialis posterior, flexor digitorum longus, and flexor hallucis longus. SYN: r. musculorum flexorum membri inferioris [TA] , laciniate ligament, ligamentum laciniatum, r. of flexor muscles. r. of flexor muscles SYN: flexor r. of lower limb. inferior extensor r. [TA] a Y-shaped ligament restraining the extensor tendons of the foot distal to the ankle joint. SYN: r. musculorum extensorum inferius [TA] , cruciate ligament of leg, inferior r. of extensor muscles, ligamentum cruciatum cruris. inferior r. of extensor muscles SYN: inferior extensor r.. inferior fibular r. [TA] broad thickened band of deep fascia overlying fibularis longus and brevis tendons as they pass along the lateral margin of the foot, anchoring the tendons and their associated bursae in place; it is a lateral continuation of the stem of the Y-shaped inferior extensor r. which attaches to the fibular trochlea of the calcaneus (which intervenes between the two tendons) and then continues to attach to the inferolateral aspect of the calcaneous. SYN: r. musculorum fibularium inferius [TA] , inferior peroneal r.&star, r. musculorum peroneorum inferius&star. inferior peroneal r. inferior fibular r.. lateral patellar r. [TA] part of the aponeurosis of the vastus lateralis muscle passing lateral to the patella to attach to the tibial tuberosity. SYN: r. patellae laterale [TA] . medial patellar r. [TA] part of the aponeurosis of the vastus medialis muscle passing medial to the patella to attach to the medial condyle of the tibia, forming the anteromedial aspect of the fibrous capsule of the knee joint. SYN: r. patellae mediale [TA] . Morgagni r. SYN: frenulum of ileal orifice. r. musculorum extensorum [TA] SYN: extensor r.. r. musculorum extensorum inferius [TA] SYN: inferior extensor r.. r. musculorum extensorum superius [TA] SYN: superior extensor r.. r. musculorum fibularium SYN: peroneal r.. r. musculorum fibularium inferius [TA] SYN: inferior fibular r.. r. musculorum fibularium superius [TA] SYN: superior fibular r.. r. musculorum flexorum [TA] SYN: flexor r.. r. musculorum flexorum membri inferioris [TA] SYN: flexor r. of lower limb. r. musculorum peroneorum SYN: peroneal r.. retinacula of nail fibrous attachments of the nail-bed to the underlying phalanx. SYN: retinacula unguis. r. patellae laterale [TA] SYN: lateral patellar r.. r. patellae mediale [TA] SYN: medial patellar r.. patellar r. extensions of the aponeuroses of the vasti medialis and lateralis muscles that pass on each side of the patella, attaching to the margins of the patella and patellar ligament anteriorly, the collateral ligaments posteriorly, and the tibial condyles distally; form the anteromedial and (with the fibrous expansion of the iliotibial tract) the anteromedial portions of the fibrous capsule of the knee. See lateral patellar r., medial patellar r.. peroneal r. superior and inferior fibrous bands retaining the tendons of the peroneus longus and brevis in position as they cross the lateral side of the ankle. SYN: retinacula of peroneal muscles, r. musculorum fibularium, r. musculorum peroneorum. r. musculorum peroneorum inferius inferior fibular r.. r. musculorum peroneorum superius superior fibular r.. retinacula of peroneal muscles SYN: peroneal r.. r. of skin SYN: skin ligaments, under ligament. superior extensor r. [TA] the ligament that binds down the extensor tendons proximal to the ankle joint; it is continuous with (a thickening of) the deep fascia of the leg. SYN: r. musculorum extensorum superius [TA] , ligamentum transversum cruris, superior r. of extensor muscles, transverse crural ligament, transverse ligament of leg. superior r. of extensor muscles SYN: superior extensor r.. superior fibular r. [TA] SYN: r. musculorum fibularium superius [TA] , r. musculorum peroneorum superius&star, superior peroneal r.&star. superior peroneal r. superior fibular r.. suspensory r. of breast suspensory ligaments of breast, under ligament. r. tendinum a ligamentous structure to restrain tendons, such as the flexor or extensor retinacula, or the annular parts of the digital fibrous sheaths. retinacula unguis SYN: retinacula of nail.
1. Relating to the retina. 2. Retinaldehyde; most commonly referring to the all-trans form. r. dehydrogenase an oxidoreductase catalyzing the interconversion of retinaldehyde and NAD+ to retinoic acid and NADH, thus affecting growth and differentiation. SYN: retinaldehyde dehydrogenase. r. isomerase an isomerase that catalyzes the cis-trans-interconversion of all-trans-r. to 11-cis-r.(dehyde); a part of the vision cycle. SYN: retinaldehyde isomerase. r. reductase alcohol dehydrogenase (NAD(P)+).
Retinol oxidized to a terminal aldehyde; retinal; a carotene released (as all-trans-retinal) in the bleaching of rhodopsin by light and the dissociation of opsin in the vision cycle. SYN: retinene-1, retinene, vitamin A aldehyde. r. dehydrogenase SYN: retinal dehydrogenase. r. isomerase SYN: retinal isomerase. r. reductase alcohol dehydrogenase (NAD(P)+).
A surgical excision of a piece of the retina.
Inflammation of the retina. [retina + G. -itis, inflammation] albuminuric r. hypertensive retinopathy. circinate r. circinate retinopathy. diabetic r. diabetic retinopathy. exudative r., r. exudativa a chronic abnormality characterized by deposition of cholesterol and cholesterol esters in outer retinal layers and subretinal space. In adults, often preceded by uveitis; in children, often preceded by retinal vascular abnormalities. SYN: Coats disease. leukemic r. leukemic retinopathy. metastatic r. purulent or septic r. resulting from the arrest of septic emboli in the retinal vessels. SYN: purulent r., septic r.. r. pigmentosa a progressive retinal degeneration characterized by bilateral nyctalopia, constricted visual fields, electroretinogram abnormalities, and pigmentary infiltration of the inner retinal layers; may be sporadic or demonstrate autosomal dominant [MIM*180100], autosomal recessive, or X-linked inheritance [MIM*268000, *312600, *312610]. SYN: pigmentary retinopathy. r. proliferans SYN: proliferative retinopathy. punctate r. retinopathy punctata albescens. purulent r. SYN: metastatic r.. r. sclopetaria a severe contusion lesion of the retina, as from a shot pellet or BB. [from sclopetum, a medieval handgun] secondary r. r. that follows uveal inflammation. septic r. SYN: metastatic r.. serous r. edema of the retina; an inflammation of the inner layers of the retina. SYN: simple r.. simple r. SYN: serous r.. r. syphilitica, syphilitic r. r. often associated with syphilitic choroiditis, especially in congenital syphilis.
The retina. [Med. L. retina]
retinoblastoma (ret′i-no-blas-to′ma) [MIM*180200, MIM*180201, MIM*180202]
Malignant ocular neoplasm of childhood, with onset usually before the third year of life, composed of primitive retinal small round cells with deeply staining nuclei and elongated cells forming rosettes; there is an increased risk of developing osteosarcoma later in life. In familial cases, the disease is usually bilateral with multiple lesions within an eye, but in sporadic cases rarely so. Autosomal dominant inheritance caused by mutation in the tumor-suppressor r. gene (RB) on chromosome 13q. [retino- + G. blastos, germ, + -oma, tumor]
Inflammation of the retina extending to the choroid. SYN: chorioretinitis. [retinochoroid + G. -itis, inflammation] bird shot r. bilateral diffuse retinal vasculitis with depigmentation of multiple areas of the choroid and retinal pigment epithelium posterior to the ocular equator, often with an associated papillitis or optic atrophy; vitiligo occurs occasionally. SYN: vitiliginous choroiditis. r. juxtapapillaris r. close to the optic disk. SYN: Jensen disease.
SYN: dialysis retinae. [retino- + G. dialysis, separation]
retinoic acid (ret-i-no′ik)
Vitamin A1 acid;retinal in which the terminal –CHO has been oxidized to a –COOH; used topically in the treatment of acne; plays an important role in growth and differentiation. SYN: vitamin A1 acid. 13-cis-r. the retinoid most used in the U.S. to treat acne; it works by reducing sebum secretion. Use in pregnancy is contraindicated because of teratogenicity.
1. Resembling a resin; resinous. [G. retine, resin, + eidos, resemblance] 2. Resembling the retina. [Mediev. L. retina] 3. In plural form, term used to describe the natural forms and synthetic analogs of retinol.
A class of keratolytic drugs derived from retinoic acid and used for treatment of severe acne and psoriasis.
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