BSC 116 Lecture Notes - Lecture 21: Microvillus, Manganese, Epiglottis
4 Jun 2016
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Nutrition: food being taken in, taken apart, and taken up. Herbivores: animals that dine on plants or algae. Omnivores: eat other animals or consume plants and algae. There are four main stages of food processing. 1: digestion- food is broken down into molecules small enough for the body to absorb. Enzymatic hydrolysis: digestive enzymes break chemical bonds; produce water and monomers: absorption- cells take up digestive products, elimination- removal of unassimilated waste. Substrate feeders- ingest substrate, eliminate most of it. Intracellular digestion: phagocytosis captures small food particles in a vacuole; digested within the cell. Gastrovascular cavity: functions for digestion and circulation extracellular digestion: gastrodermis secretes enzymes. Complete gut (alimentary canal) one way gut food goes in one opening and out another allows gut to be specialized for sequential food processing; very efficient. Food is pushed along the alimentary canal by peristalsis, alternating waves of contraction and relaxation in the smooth muscle muscles lining the canal.
