Glands, digestive salivary

Snake venoms a mixture of toxins produced in the venom glands (parotid gland, or salivary gland of the upper jaw) of venomous snakes (asps or hooded snakes, e.g. the cobra sea snakes vipers, e.g. puff adder, rattlesnake). They consist of highly toxic, antigenic polypeptides and proteins (which cause paralysis and death of the prey), and enzymes (which facilitate the spread of the toxins, and initiate digestion of undivided swallowed prey). The enzymes indude hya-luronidase (promotes spread of toxins), ATPase and acetylcholine esterase (paralysis), phospholipases (hemolysis), proteinases and L-amino add oxidases (tissue necrosis and blood clotting). 

Salivary glands— The salivary glands represent a network of accessory structures which are essential to digestion. Three pairs of salivary glands are of primary importance— parotid, submaxillary, and sublingual. Fig. D-18 illustrates the location of these glands. 

The mutation lethal-meander (Ime, 2-71 and 73 Lindsley and Grell, 1967) has an early effect on larval development. This mutation inhibits larval growth and is characterized by a very low concentration of DNA and RNA in the salivary glands, digestive tube, and other organs. The RNA/DNA ratio (2, 2-3, 4) is also reduced as compared to the normal (8.8-10.8). However, 28S and 18S RNA are synthesized with delay. Therefore, this mutation affects only the time of transcription (Chen et al., 1963 Weideli et al., 1969 Kubli, 1970 Chen, 1971 Kubli et al., 1971). 

The cephalopods often secrete venom from their posterior salivary glands and hence secretion of venom probably forms part of the process of digestion. Cephalopods include species, such as octopi, capable of injecting various venoms including simple amines such as tetramine. On the other hand, maculotoxin isolated from the octopus H. maculosa was eventually determined to be tetrodotoxin 24 ). 

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 ... 

Sulfation has also been documented in salivary proteins, specifically statherin. The enzymes in saliva are the first wave of the human digestion process and statherin prevents the precipitation of calcium phosphate in the salivary gland and saliva. Since TPST is secreted along with statherin, sulfation plays a role in digestion by binding hydroxylapatite and preventing its precipitation. 

Saliva. The salivary glands produce a slightly alkaline secretion which—in addition to water and salts—contains glycoproteins (mucins) as lubricants, antibodies, and enzymes. a-Amylase attacks polysaccharides, and a lipase hydrolyzes a small proportion of the neutral fats. a-Amylase and lysozyme, a mu-rein-cleaving enzyme (see p. 40), probably serve to regulate the oral bacterial flora rather than for digestion (see p. 340). 

Digestion begins here. Saliva produced by the salivary glands moistens the dry feed so that it is easier to swallow. At this point the feed, if accepted, is swallowed whole. The feed then passes quickly to a pouch in the oesophagus, the crop. 

Q6 Alpha-amylase (a-amylase) is concerned with the digestion of starch to disaccharides and other products in the gut. The salivary glands also produce a-amylase, the parotid glands producing the greatest amount. 

D-1) Amylase testing. Amylase is a digestive enzyme that is produced mainly by the salivary glands and pancreas. It may be elevated in the serum in mumps or in pancreatitis, but sometimes in other conditions (e.g., peptic ulcer, intestinal obstruction, gallstones). 

Secretion of Digestive Materials Salivary Glands Ftmdus of the Stomach Antrum of the Stomach Pancreas and Small Intestines Liver and Gall Bladder Small Intestine... 

---