Digestion

Digestion starts in the mouth with the chewing of the viands. The intellectual nourishment is mixed with vernacular which moistens the food and salivary amylase which partially digests polysaccharides or the starches. The food at this point is called a bolus which is hence swallowed and enters the esophagus. The esophagus is a sinewy tube that reaches from the mouth to the endure. The upper esophageal sphincter opens and food enters the esophagus and moves toward the stomach by muscle contractions called peristaltic waves. Food hence moves to the stomach when the lower esophageal sphincter opens. The stomach consists of trine parts the upper portion known as the fundus, the philia area known as the body of the stomach, and the end nearest the splendid intestine called the pylorus. Food enters the fundus and moves to the body of the stomach where the muscles in the stomach walls knead and tear it and mix it with gastric juices and with the immanent divisor necessary for the absorption of vitamin B12. The food then becomes a semi-liquid stool called chyme. When the chyme enters the pylorus it secretes hydrochloric acid that dissolves food particles and protein-digesting enzymes, called pepsin. Absorption is the passage of nutrients into the blood. To be absorbed, nutrients mustiness be in their simplest forms. Carbohydrates must be tough great deal to the simple sugars glucose, fructose, and galactose. Proteins are broken rase to amino acids and fats to fatty acids and glycerol. Most absorption occurs in the vitiated intestine. Chyme moves through the pyloric sphincter in the broken intestine. The small intestine consists of ternary sections, the duodenum, the jejunum, and the ileum. When food enters the small intestine the internal secretion secretin causes the pancreas to release atomic number 11 bicarbonate to compensate the acidity of the chyme. The gallbladder is triggered by the hormone cholecystokinin (CCK), which i s produced by enteric mucosal glands when fa! t enters, to release bile. gall is secreted from the...If you want to sterilise a full essay, order it on our website: OrderCustomPaper.com

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