Kin 110 - Chapter 3

KIN 110 – CHAPTER 2 Digestion: The process of transforming the foods into units for absorption Absorption: Movement of substances into or across tissues Chemosenses: Chemical sensing system in body, taste and smell - Olfactory Cells: Smell cells - Gustatory Cells: Taste cells Cephalic Phase Responses: Psychological responses triggered by sight, smell, thought, taste and sound of food GI Tract Gastrointestinal Tract: Hollow tube that begins at the mouth, and ends at the anus -Innermost-Outer: Lumen, Epithelium, mucosa, submucosa, circular muscle, longitudinal muscle serosa Sphincters: Circular band of muscle fibers that act as entranceways Chyme: Partially digested food and digestive juices Peristalsis: Intestinal movement of moving forward Segmentation: Intestinal movement of mixing Digestion Process Enzymes: Proteins in the body which speed up reactions, but is unchanged Hydrolysis: To split compounds through the addition of water Nutrient Absorption Passive Diffusion: Simple diffusion from high to low concentration Facilitated Diffusion: Diffusion via carrier protein transport Active Transport: Transport across membranes from low to high concentrations, requiring energy in the process (ATP) Endocytosis: Uptake of a material by a cell by the indentation and pinching off of its membrane to form a vesicle that carries material into the cell Pinocytosis: Process of endocytosis, for fluids and macromolecules Phagocytosis: Process of endocytosis, for large particles and small microorganisms Digestive Assisting Organs Salivary Glands: Produces saliva Liver: Produces bile Emulsifier: Term for agents that break up fat into smaller molecules Bile: An emulsifying agent, produced by liver, stored in gallbladder Enteroheptaic Circulation: Process of recycling bile from the intestine back into the liver Gallbladder: Stores bile Cholecystokinin (CCK): Hormone that stimulates the release of digestive enzymes from pancreas and bile gallbladder Pancreas: Organ that secretes enzymes and hormones Digestion Tract Mouth Food goes into the mouth, then is wetted with amylase, which breaks starch into sugar. Lingual Lipase starts fat digestion and the chewed, moistened food becomes a bolus. Then bolus then slides down to the stomach through the esophagus. The esophageal sphincter opens and lets food into the stomach. Stomach The stomach has hydrochloric acid with a pH of 2. Mucus protects the stomach lining. The hydrochloric acid digests protein by turning the shape of protein i