digestive tract

tract (trakt)

1. a region, principally one of some length.

2. a bundle of nerve fibers having a common origin, function, and termination.

3. a number of organs, arranged in series and serving a common function.

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alimentary tract  see under canal.

atriohisian tracts  myocardial fibers that bypass the physiologic delay of the atrioventricular node and connect the atrium directly to the bundle of His, allowing preexcitation of the ventricle.

biliary tract  the organs, ducts, etc., participating in secretion (the liver), storage (the gallbladder), and delivery (hepatic and bile ducts) of bile into the duodenum.

digestive tract  alimentary canal.

dorsolateral tract  a group of nerve fibers in the lateral funiculus of the spinal cord dorsal to the posterior column.

extracorticospinal tract , extrapyramidal tract extrapyramidal system.

Flechsig's tract  posterior spinocerebellar t.

gastrointestinal tract  the stomach and intestine in continuity.

genitourinary tract  urogenital system.

Gowers' tract  anterior spinocerebellar t.

iliotibial tract  a thickened longitudinal band of fascia lata extending from the tensor muscle downward to the lateral condyle of the tibia.

intestinal tract  the small and large intestines in continuity.

nigrostriatal tract  a bundle of nerve fibers extending from the substantia nigra to the globus pallidus and putamen in the corpus striatum; injury to it may be a cause of parkinsonism.

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 tract  two groups of nerve fibers arising in the brain and passing down through the spinal cord to motor cells in the anterior horns.

respiratory tract  see under system.

reticulospinal tract  a group of fibers arising mostly from the reticular formation of the pons and medulla oblongata; chiefly homolateral, the fibers descend in the ventral and lateral funiculi to most levels of the spinal cord.

spinocerebellar tract, anterior  a group of nerve fibers in the lateral funiculus of the spinal cord, arising mostly in the gray matter of the opposite side, and ascending to the cerebellum through the superior cerebellar peduncle.

spinocerebellar tract, posterior  a group of nerve fibers in the lateral funiculus of the spinal cord, arising mostly from the nucleus thoracicus, and ascending to the cerebellum through the inferior cerebellar peduncle.

spinothalamic tract  a group of nerve fibers in the lateral funiculus of the spinal cord that arise in the opposite gray matter and ascend to the thalamus, carrying the sensory impulses activated by pain and temperature.

urinary tract 

1. see under system.

2. sometimes more specifically the conduits leading from the pelvis of the kidneys to the urinary meatus.

urogenital tract  see under system.

uveal tract  the vascular tunic of the eye, comprising the choroid, ciliary body, and iris.

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digestive tract

n.

See alimentary canal.

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Digestive tract

The organs that perform digestion, or changing of food into a form that can be absorbed by the body. They are the esophagus, stomach, small intestine, and large instestine.

Mentioned in: Antigas Agents, Bariatric Surgery, Fluoroquinolones

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digestive tract,

a musculomembranous tube, about 9 m long, extending from the mouth to the anus and lined with mucous membrane. Its various portions are the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. The tube, which is part of the digestive system, includes numerous accessory organs. Also called alimentary canal, alimentary tract, digestive tube, gastrointestinal tract, intestinal tract, intestinal tubes. See also digestive system.

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digestive

pertaining to digestion.

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digestive enzymes

include salivary (amylase), gastric (pepsin), pancreatic (trypsin, chymotrypsin, amylase, lipase), small intestinal mucosa (carbohydrases including isomaltase, lactase, maltase, sucrase, trehalase).

digestive inoculant

administered mostly to neonates primarily to provide an inoculum of beneficial bacteria and protozoa essential to proper digestion and usually picked up from the environment. In many commercial products the irresistible temptation to include other materials, including dietary essential vitamins and minerals, clouds the effect of the inoculant, and may, as in iron poisoning in foals, cause disaster.

digestive system

the organs that have as their particular function the ingestion, digestion and absorption of food or nutritive elements. They include the mouth, teeth, tongue, pharynx, esophagus, stomach and intestines. The accessory organs of digestion, which contribute secretions important to digestion, include the salivary glands, pancreas, liver and gallbladder. Birds have an unusual system in that there are no teeth and no soft palate in most. There is a pregastric buffer, the crop; the stomach is separated into two organs, one secretory and one muscular, and the large intestine is replaced by a dual cecum. The rectum empties into a cloaca which is shared with the urogenital tract. The ruminant system is complicated by the presence of the forestomachs, the reticulum, rumen and omasum, and there are no upper incisor teeth. The peculiarities of horses are the greatly distended large intestine and the absence of a gallbladder.

digestive tract

the digestive system less the ancillary organs of salivary glands, liver and pancreas; the luminal organs through which food passes. See also alimentary canal.