NURS 220 Lecture Notes - Lecture 25: Esophagus, Pylorus, Stomach
Document Summary
Synthesis of organic building block by plants use energy from sun to form carbon/hydrogen/oxygen bonds and release oxygen. Gastrointestinal tract (gi tract)-open ended tube at both ends. Have to absorb nutrients through wall of tube. Structure of the tract-gi tract separates the lumen from body proper does this by tight junctions. Epithelium-faces the lumen with tight junctions between cells and can also secrete. Lamina-connective tissue that provides blood supply muscularis mucosa-outer most layer of mucosa-thin layers of smooth muscle b) c) Muscularis-thicker layers of smooth muscle-major movements (contains circular, oblique, and longitudinal muscles) Serosa-double layer of wrapping around the entire tract. Contribution to homeostasis-replenish water, salts, nutrients, and vitamins. Pancreas-1500, small intestine-1500, large intestine-500 + whatever you take in. Most reabsorptions (8000l) happens in small intestine, (350l reabsorbed in large intestine). Secrete water, salts, enzymes, emulsifiers (helps digest fats) Peristalsis-wave of smooth muscle contraction moves food down tube.