gastrointestinal tract

(redirected from Digestive systems)
Also found in: Dictionary, Thesaurus, Encyclopedia.

tract

 [trakt]
a longitudinal assemblage of tissues or organs, especially a number of anatomic structures arranged in series and serving a common function, such as the gastrointestinal or urinary tract; also used in reference to a bundle (or fasciculus) of nerve fibers having a common origin, function, and termination within the central nervous system.
alimentary tract alimentary canal.
biliary tract the organs, ducts, and other structures that participate in secretion (the liver), storage (the gallbladder), and delivery (hepatic and bile ducts) of bile into the duodenum. See illustration.
Anatomy of the gallbladder and biliary tract. From Aspinall and Taylor-Robinson, 2002.
corticospinal t's two groups of nerve fibers (the anterior and lateral corticospinal tracts) that originate in the cerebral cortex and run through the spinal cord.
digestive tract alimentary canal.
dorsolateral tract a group of nerve fibers in the lateral funiculus of the spinal cord dorsal to the posterior column.
extrapyramidal tract extrapyramidal system.
gastrointestinal tract the stomach and intestine in continuity; see also digestive system.
iliotibial tract a thickened longitudinal band of fascia lata extending from the tensor muscle downward to the lateral condyle of the tibia.
intestinal tract see intestinal tract.
optic tract the nerve tract proceeding backward from the optic chiasm, around the cerebral peduncle, and dividing into a lateral and medial root, which end in the superior colliculus and lateral geniculate body, respectively.
pyramidal t's collections of motor nerve fibers arising in the brain and passing down through the spinal cord to motor cells in the anterior horns.
respiratory tract respiratory system.
urinary tract the organs and passageways concerned in the production and excretion of urine from the kidneys to the urinary meatus; see also urinary system.
uveal tract the vascular tunic of the eye, comprising the choroid, ciliary body, and iris.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

gas·tro·in·tes·ti·nal tract

(G.I. tract) the stomach, small intestine, and large intestine; often used as a synonym of digestive tract.
Farlex Partner Medical Dictionary © Farlex 2012

gas·tro·in·tes·ti·nal tract

(gastrō-in-testi-năl trakt)
Stomach, small intestine, and large intestine; often used to mean digestive tract.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

gastrointestinal tract

See ALIMENTARY CANAL.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

Gastrointestinal tract

The entire length of the digestive system, running from the stomach, through the small intestine, large intestine, and out the rectum and anus.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Water sometimes needs a bit of help, however, in order to do the most for the digestive system.
Regular exercise and a diet that is high in "healthy fibre" work as a team with water to keep the digestive system humming.
And how about when they are back to normal and their digestive system is working better?
A Dr Rob Hicks, GP, writes: Our digestive systems begin to struggle as we get older and it's common to not be able to cope with the rich meals you once could.
If you are eating out, drinking water rather than wine will also help reduce the strain on your digestive system.
McMahon of the University of Texas at Arlington says, "Zebra mussels take this stuff out the water column and concentrate it in their digestive systems to levels that are toxic." Aquatic organisms that don't filter feed, as mussels do, would take in only inconsequential amounts of the toxicant, he adds.
Some other worms from the deep have no digestive systems but depend on live in bacteria for nourishment, explains Robert Vrijenhoek of the Monterey Bay Aquarium Research Institute in Moss Landing, California.
"Bacteria in the groundwater don't have the correct digestive systems to degrade MTBE," Landmeyer notes, nor do they have access to oxygen.
Benner and his colleagues studied a protein, a form of the enzyme ribonuclease, that breaks down bacterial RNA in the digestive systems of cows, sheep, deer, giraffes, and other ruminants.
The gene codes for the production of a protein, called Bt, which paralyzes the digestive systems of insects and caterpillars with nonacidic "stomachs." Bt has for decades been sprayed on vegetable crops and trees to protect them from insect pests; it appears to have no effect on humans or other animals with acidic digestive tracts.