Digestion

Digestion starts in the mouth with the chewing of the viands. The food is mixed with tongue 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 muscular 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 then moves to the stomach when the lower esophageal sphincter opens.
The stomach consists of triplet parts the upper portion known as the fundus, the middle 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 intrinsic 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 broken great deal to the simple sugars glucose, fructose, and galactose. Proteins are broken down to amino acids and fats to fatty acids and glycerol. Most absorption occurs in the small intestine.
Chyme moves through the pyloric sphincter in the small intestine. The small intestine consists of ternary sections, the duodenum, the jejunum, and the ileum. When food enters the small intestine the hormone secretin causes the pancreas to release atomic number 11 bicarbonate to neutralize the acidity of the chyme. The gallbladder is triggered by the hormone cholecystokinin (CCK), which is produced by intestinal mucosal glands when fat enters, to release bile. gall is secreted from the...If you want to get a full essay, order it on our website: Ordercustompaper.com



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