neural tube

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tube

 [to̳b]
a hollow cylindrical organ or instrument. adj., adj tu´bal.
auditory tube eustachian tube.
Blakemore-Sengstaken tube Sengstaken-Blakemore tube.
chest tube see chest tube.
Dobhoff tube a small-lumen feeding tube that can be advanced into the duodenum.
drainage tube a tube used in surgery to facilitate escape of fluids.
Drieling tube a double-lumen tube having a metal weight at one end to carry it past the stomach into the duodenum. At the other end are two tails, one used to collect gastric specimens and the other to collect specimens from the duodenum. The tube is used in the secretin test for pancreatic exocrine function.
Durham's tube a jointed tracheostomy tube.
endobronchial tube a single- or double-lumen tube inserted into the bronchus of one lung and sealed with an inflatable cuff, permitting ventilation of the intubated lung and complete deflation of the other lung; used in anesthesia and thoracic surgery.
endotracheal tube see endotracheal tube.
esophageal tube stomach tube.
eustachian tube see eustachian tube.
Ewald tube a large lumen tube used in gastric lavage.
fallopian tube see fallopian tube.
feeding tube one for introducing high-caloric fluids into the stomach; see also tube feeding.
tube feeding a means of providing nutrition via a feeding tube inserted into the gastrointestinal tract; it may be done to maintain nutritional status over a period of time or as a treatment for malnutrition. It can be used as the only source of nutrition or as a supplement to oral feeding or parenteral nutrition.

Patients who may require tube feeding include those unable to take in an adequate supply of nutrients by mouth because of the side effects of chemotherapy or radiation therapy, those with depression or some other psychiatric disorder, and those suffering from severe hypermetabolic states such as burns or sepsis, or malabsorption syndromes. Other conditions that may require tube feeding include surgery or trauma to the oropharynx, esophageal fistula, and impaired swallowing such as that which occurs following stroke or that related to neuromuscular paralysis.

There are commercially prepared formulas for tube feeding. Some contain all six necessary nutrients (carbohydrates, fats, proteins, vitamins, minerals, and trace elements) and need no supplement as long as they are given in sufficient volume to meet nutritional and caloric needs. Other types of tube feeding formulas are incomplete and therefore will require some supplementation. Choice of formula is based on the patient's particular needs, presence of organ failure or metabolic aberration, lactose tolerance, gastrointestinal function, and how and where the feeding is to be given, that is, via nasogastric, gastrostomy, or enterostomy tube.
Patient Care. In addition to frequent and periodic checking for tube placement and monitoring of gastric residuals to prevent aspiration, other maintenance activities include monitoring effectiveness of the feeding and assessing the patient's tolerance to the tube and the feeding. Special mouth care is essential to maintain a healthy oral mucosa. A summary of the complications related to tube feeding, their causes and contributing factors, and interventions to treat or prevent each complication is presented in the accompanying table.
fermentation tube a U-shaped tube with one end closed, for determining gas production by bacteria.
Levin tube a gastroduodenal catheter of sufficiently small caliber to permit transnasal passage; see illustration.
Two types of nasogastric tubes. From Ignatavicius et al., 1995.
Linton tube a triple-lumen tube with a single balloon used to control hemorrhage from esophageal varices. Once it is positioned under fluoroscopic control and inflated, the balloon exerts pressure against the submucosal venous network at the cardioesophageal junction, thus restricting the flow of blood to the esophageal varices.
Miller-Abbott tube see miller-abbott tube.
Minnesota tube a tube with four lumens, used in treatment of esophageal varices; having a lumen for aspiration of esophageal secretions is its major difference from the sengstaken-blakemore tube.
nasogastric tube see nasogastric tube.
nasotracheal tube an endotracheal tube that passes through the nose.
neural tube the epithelial tube produced by folding of the neural plate in the early embryo.
orotracheal tube an endotracheal tube that passes through the mouth.
otopharyngeal tube eustachian tube.
Rehfuss tube a single-lumen oral tube used to obtain specimens of biliary secretions for diagnostic study; it is weighted on one end so that it can be passed through the mouth and positioned at the point where the bile duct empties into the duodenum. See also biliary drainage test.
Salem sump tube a double-lumen nasogastric tube used for suction and irrigation of the stomach. One lumen is attached to suction for the drainage of gastric contents and the second lumen is an air vent. See illustration.
Sengstaken-Blakemore tube see sengstaken-blakemore tube.
stomach tube see stomach tube.
T-tube one shaped like the letter T and inserted into the biliary tract to allow for drainage of bile; it is generally left in place for 10 days or more in order to develop a tract through which bile can drain after the tube is removed. A T-tube cholangiogram is usually performed prior to removal of the tube in order to determine that the common duct is patent and free of stones. If stones are found they can be removed through the tube tract by instruments inserted under x-ray guidance.
test tube a tube of thin glass, closed at one end; used in chemical tests and other laboratory procedures.
thoracostomy tube a tube inserted through an opening in the chest wall, for application of suction to the pleural cavity; used to drain fluid or blood or to reexpand the lung in pneumothorax. See also chest tube.
tracheal tube endotracheal tube.
tracheostomy tube a curved endotracheal tube that is inserted into the trachea through a tracheostomy; see discussion under tracheostomy.
tympanostomy tube ventilation tube.
uterine tube fallopian tube.
ventilation tube a tube inserted after myringotomy in chronic cases of middle ear effusion, such as in secretory or mucoid otitis media; it provides ventilation and drainage for the middle ear during healing, and is eventually extruded. Called also tympanostomy tube.
Tympanostomy (ventilation) tube. Polyethylene tubes are inserted surgically into the eardrum to relieve middle ear pressure and promote drainage of chronic or recurrent middle ear infections. Tubes extrude spontaneously in 6 months to 1 year. From Jarvis, 1996.
Wangensteen tube a small nasogastric tube connected with a special suction apparatus to maintain gastric and duodenal decompression.
Whelan-Moss T-tube a t-tube whose crossbar tube is larger in diameter than the drainage tube.
x-ray tube a glass vacuum bulb containing two electrodes; electrons are obtained either from gas in the tube or from a heated cathode. When suitable potential is applied, electrons travel at high velocity from cathode to anode, where they are suddenly arrested, giving rise to x-rays.

neu·ral tube

the epithelial tube formed from the neuroectoderm of the early embryo by the closure of the neural groove; by complex processes of cell proliferation and organization, the neural tube develops into the spinal cord and brain.
Synonym(s): medullary tube

neural tube

n.
A dorsal tubular structure in the vertebrate embryo that is formed by longitudinal folding of the neural plate and that differentiates into the brain and spinal cord.

neural tube

the longitudinal tube, lying along the central axis of the early developing embryo, that gives rise to the brain, spinal cord, and other neural tissue of the central nervous system. Also called cerebromedullary tube, medullary tube. See also neural tube defect.

neural tube

the ectodermal tube formed along the back of the developing embryo, which develops into the brain and spinal cord.

neural

pertaining to a nerve or to the nerves.

neural crest cells
a group of neuroepithelial cells which condenses dorsal to the neural tube in the embryo; they subsequently migrate and set up dorsal root ganglia, the ganglia of the autonomic nervous system, and the pigment cells of the integument (melanocytes).
neural folds
in the embryo, the sides of the invaginated neural plate that meet and fuse over the neural groove to form the neural tube.
neural groove
the longitudinal furrow in the neural plate of the embryo.
neural lymphomatosis
neural plate
the thickened ectoderm dorsal to the notochord in the embryo that gives rise to the neural tube.
neural retina
separated from the outer layer of the optic retina by the intraretinal space; constitutes the pars optica retinae, with its neuroepithelial layer (contains rods and cones—the receptor cells), bipolar ganglion layer, multipolar ganglion layer, and a layer of axons of the latter layer. Light must pass through the latter three layers before reaching the receptor cells.
neural substrates
functional units of the central nervous system, often composed of a series of structural units which may be widely separated anatomically but which interact to support or drive complex nervous system functions, such as hunger and sleepiness. They are the counterparts of simple centers, e.g. the respiratory center, which control simple physiological mechanisms.
neural tropic influence
the tropic influence of nerves on, for example, muscle, demonstrated by the atrophy of muscle when it is denervated.
neural tube
the precursor of the central nervous system in the embryo, formed by invagination and fusion of the neural plate.