Physiology 2130 Lecture Notes - Lecture 1: Pepsin, Parotid Gland, Antrum
28 Feb 2018
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Document Summary
4 processes of digestive system: secretion: release of enzymes into digestive tract, digestion: mechanical and chemical (amylase and lipase) Breaking down large molecules into smaller soluble molecules: motility: movement of food down the digestive tract, absorption: transport of substances from lumen of digestive tract to blood. Saliva is secreted (chemical breakdown of food) Mucus is major component of saliva produced in mucous cells found in salivary glands. Stages of swallowing: bolus being passed through esophagus to stomach: voluntary stage, pharyngeal stage, esophageal. Mechanical manipulation of food into bolus (lump of food) Chemical digestion with secretion of salivary amylase and lingual lipase. Coordinated contractions and relaxation of circular and longitudinal muscles. Secondary peristalsis initiated when food is still lodges. Propels bolus towards stomach (without gravitational force) Reservoir for food before absorption in intestines. Chemical breakdown of gastric juices (2-3l secreted per day) Glands: within stomach wall of fundus secreting mucus to lubricate the bolus.
