Esophagus

The GI tract consists of mouth and esophagus, stomach, small intestine (duodenum, jejunum, and ileum), and large intestine (colon and rectum). 

The composition, pH, and volume of salivary excretion for different salivary glands vary. Usually 1-2 L of saliva are secreted per day. Saliva is a hypotonic solution with a pH of about 7.0 principal cations are Na and K+, and anions are Cl andHCOj. Aldosterone (a steroid hormone of the adrenal cortex) modulates Na+ and K levels in saliva as it does in the kidney (Chapter 32). Aldosterone increases reabsorption of Na+ and secretion of K+ by direct action on the salivary gland ducts. In hypoaldosteronism (e.g., Addison s disease), the salivary Na /K+ ratio is high. 

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A small amount of acrolein may be fatal if swallowed. It produces bums of the mouth, throat, esophagus, and stomach. Signs and symptoms of poisoning may include severe pain in the mouth, throat, chest, and abdomen nausea vomiting, which may contain blood diarrhea weakness and dizziness and coUapse and coma (99). 

Swallowing acryhc monomers may produce severe irritation of the mouth, throat, esophagus, and stomach, and cause discomfort, vomiting, diarrhea, dizziness, and possible coUapse. 

The largest use of endoscopic techniques is in the examination of the gastrointestinal tract. Upper intestinal endoscopy is the examination of the esophagus, stomach, and proximal duodenum. Colonoscopy is the examination of the colon, large intestine, and in some cases the distal parts of the small intestine. Cholangiopancreatography is the examination of the biUary tree and pancreas. 

Swallowing. If it is sufficiently irritant or caustic, a swallowed material may cause local effects on the mouth, pharynx, esophagus, and stomach. Additionally, carcinogenic materials may induce tumor formation in the alimentary tract. Also, the gastrointestinal tract is an important route by which toxic materials are absorbed. The sites of absorption and factors regulating absorption have been reviewed (42,43). 

Inhibition of Nitrosamine Formation. Nitrites can react with secondary amines and A/-substituted amides under the acidic conditions of the stomach to form /V-nitrosamines and A/-nitrosamides. These compounds are collectively called N-nitroso compounds. There is strong circumstantial evidence that in vivo A/-nitroso compounds production contributes to the etiology of cancer of the stomach (135,136), esophagus (136,137), and nasopharynx (136,138). Ascorbic acid consumption is negatively correlated with the incidence of these cancers, due to ascorbic acid inhibition of in vivo A/-nitroso compound formation (139). The concentration of A/-nitroso compounds formed in the stomach depends on the nitrate and nitrite intake. 

The e. posure route partly determines the distribution of the chemical in die body. Like tlie chemical benzene, a single chemical may follow multiple routes of e. posure. The liver, like the skin, acts as a filter. The liver is the primary dcto.xification site. To.xicants that arc absorbed into the lungs, skin, mouth, and esophagus may temporarily bypass the liver however, toxicants absorbed tluougli the stomach and intestines follow the blood s direct path to tlie liver. 

Schlund, m. throat, pharynx gulf, chasm. Schlund-. pharyngeal, -kopf, m. upper phar ynx. -rohr, n., -rohre, /. esophagus. 

AIDS (acquired immunodeficiency syndrome) is the final stage of disease caused by infection with HIV. In this stage, the vims infection has severely affected the immune system, causing a depletion of CD4+ T-helper cells. AIDS is characterized by the manifestation of typical diseases caused by opportunistic infections (Pneumocystis carinii pneumonia, CMV retinitis, candidiasis of the esophagus, cerebral toxoplasmosis), neurological manifestations, cachexia, or certain tumors (Kaposi sarcoma of the skin, B-cell lymphoma). 

Human GAL1 receptor mRNA has been detected in multiple cell and tissue samples including Bowes melanoma cells, brain, gastrointestinal tract (from esophagus to rectum), heart, prostate, and testes. Rat GAL1 mRNA was detected in olfactory regions, many hypothalamic nuclei (including supraoptic nucleus),... 

Ca oxalate is corrosive and produces local irritation. It has a caustic effect on mouth, esophagus and stomach, and can cause severe damage to kidneys (Refs 6 9). It can be dangerous when heated to decompn because of toxic fumes (Ref 6)... 

Instruct the patient to place the pill or capsule on the back of the tongue and tilt the head back to swallow a tablet or slightly forward to swallow a capsule. Encourage the patient first to take a few sips of water to move the drug down the esophagus and into the stomach, and then to finish the whole glass. 

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