BIOM 2000 Lecture Notes - Lecture 23: Pylorus, Gastric Glands, Chyme
16 Mar 2016
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Document Summary
Nutrient homeostasis and the role of digestive system: Living cells require a constant supply of energy and the digestive system, linked to cns, attempt to supply the demand. Serosal layer overlies layers of smooth muscles, some running along the length of the tract, some encircling the tract. Beneath the muscles is a submucosal layer (glands) of connective tissue, and below that the mucosa. Mucosa consists of a layer of smooth muscle, surrounding a connective tissue layer, and the inner epithelial layer. *diagram page 8 (primary in black, secondary in blue) Tongue and teeth are used to chew food in oral cavity. Saliva is secreted into oral cavity; saliva contains salivary amylase, which begins the digestion of carbs and mucus, which moistens and lubricates the food to ease swallowing. As food is swallowed, it"s passed to pharynx; region where respiratory and digestive tract separate. 2 major phases: buccal phase (voluntary) and pharyngeal esophageal (involuntary, controlled by pns)
