Mouth, digestion

Many of the animals harbor endosymbiotic bacteria that are sulflde oxidizers, such as the giant tube worms Riftta pachyptila), which reach lengths of 1 m. As shown in Figure 19.19, the tube worms are essentially a closed sac, having no mouth, digestive system, or other means of processing particulate food. 

Toxicology May cause skin irritation inh. of mist may cause respiratory tract irritation may cause eye irritation, burning sensation, paint, cor-neal/conjunctival ulceration ing. may cause severe burning in mouth/ digestive tract TSCA listed Hazardous Decorrp. Prods. Combustion CO,... 

Properties Wh. glassy noncryst. solid clear odorless misc. with acetic acid, acetone, benzene. CCI diethyl ether. MIBK. MEK. PEGs. toluene, r lene. etc. insol. in water, aliphatic hydrocarbons m.w. 1110 sp.gr. 1.25 soften, pt. (B R) 98 C acid no. < 0.1 iodine no. < 0.01 sapon. no. 153 hyd. no. 0.9 flash pt. (TOC) 260 C ref. index 1.577 Toxiariogy LD50 (oral, rat) > 5 g/kg not a primary skin/eye irritant may cause skin irritation inh. of mist may cause respiratory tract irritation may cause eye irritation, pain, comeal/conjunctival ulceration ing. may cause burning in mouth/digestive TSCA listed Hazardous Decomp. Prods. Combustion CO,... 

Biological Applications Antimalarial agent protein assay detecting enzyme activity treating cancer, malaria, diabetes, a variety of conditions affecting skin, mouth,digestive tract,urinary tract, reproductive tract, respiratory tract, circulatory system, head, neck, endocrine system, lymphoreticular sys-tem dental materials ... 

Acarbose is a nonabsorbable a-glucosidase inhibitor which blocks the digestion of starch, sucrose, and maltose. The digestion of complex carbohydrates is delayed and occurs throughout the small intestine rather than in the upper part of the jejunum. Absorption of glucose and other monosaccharides is not affected. Acarbose is adrninistered orally three times a day and chewed with the first mouthful of food. 

Oral Toxicity. Alkan olamines generally have low acute oral toxicity, but swallowing substantial quantities could have serious toxic effects, including injury to mouth, throat, and digestive tract. 

Concentrated monoethan olamine and monoisopropan olamine can cause severe local irritation or even bums to the mouth, throat, and digestive tract. If monoethan olamine and monoisopropan olamine are swallowed, large volumes of milk or water should be administered immediately. If diethanolamine, triethanolamine, diisopropanolamine, or triisopropanolamine are swallowed, vomiting should be induced after drinking two glasses of water. 

Mund-verdauung, /, oral digestion, -wasser, n. gargle, mouth wash. 

When you eat starchy foods, they are broken down into glucose by enzymes. The process starts in your mouth with the enzyme amylase found in saliva. This explains why, if you chew a piece of bread long enough, it starts to taste sweet The breakdown of starch molecules continues in other parts of the digestive system. Within 1 to 4 hours after eating, all the starch in food is converted into glucose. 

One bodily function that relies on acids and bases is the process of digestion. During digestion, food is broken down into small molecules that the body can use. Digestion begins in the mouth when food comes into contact with an enzyme called amylase found in the saliva. Enzymes are the body s catalysts. They speed up chemical reactions that would otherwise be too slow to be useful to the body. Amylase breaks down starch molecules and converts them into sugars. 

The mouth is the region from the lips to the pharynx. The first step in the digestive process is chewing, or mastication, which is an initial mechanical breakdown of the food that facilitates its movement to the stomach. The mouth is lined with stratified squamous epithelium that provides extra protection from injury by coarse food materials. Three pairs of salivary glands secrete saliva into the oral cavity ... 

The digestive system of poultry is also basically a tube, beginning at the mouth and ending at the vent (Fig. 13.1). Food is taken in via the mouth and mixed with saliva to lubricate it. The bolus moves down the oesophagus by gravity and a wave-like contraction of the muscles (peristalsis). Then it enters the crop where it is stored if the stomach is full. A certain amount of softening and fermentation may occur here. The crop is situated just outside the entrance of the chest cavity (thoracic inlet) and is an expansion of the oesophagus. 

Enteric bacterial pathogens must maneuver through a lengthy stretch of hazardous terrain before they reach their intended target or infection site within a host. Initially, they must tolerate salivary enzymes having various hydrolytic activities in the mouth, followed by exposure to shedded epithelial cells in the esophagus that may prevent local bacterial adherence (Pearson and Brownlee, 2005). In the stomach, bacteria must endure another severe environment created by the secretion of digestive enzymes and hydrochloric acid (up to 0.1 M concentration and a pH as low as 1.0). Once bacteria reach the intestines, they then encoimter mechanical. 

Adequate vitamin A is also required for the health of the surface structures of the human body skin, the lining of the digestive system, lungs, and mouth. These structures, particularly the skin, are an important part of the human defense system against infection. When they are compromised, the human body becomes increasingly susceptible to infection, a profound problem in areas of poor public health resources. This story, and what has been done in response, is beautifully told in Philip Hilts book Rxfor Survival. ... 

Suppose we start with a starch-rich meal, say one containing a lot of pasta or bread. The digestion of starches begins in the mouth. Saliva contains an enzyme, salivary amylase (aka ptyalin), which catalyzes the conversion of starch to simple sugars such as glucose. This process is completed in the small intestine under the influence of other enzymes in the amylase class. This completes the first phase of carbohydrate catabolism the conversion of complex, polymeric carbohydrates (e.g., starches) to their simple monomeric units, the sugars. 

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