Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Unit 2: Internal Systems Components of The Digestive System I Components of the Digestive System Homework take-up Teeth: Incisors (8) Canines (4) Premolars or bicuspids(8) Molars (12) Components of the Digestive System Tongue: Different parts of the tongue are able to taste one of four basic tastes. sour salty bitter sweet Components of the Digestive System Kinds of Teeth Canines Description long & pointy sharp Function rip/tear very developed in predators Incisors wide, but very thin bumps on bottom edges Premolars flat & broad have 2 bumps on surfaces called cusps (bicuspids) grinding & mashing flat & broad have 4 cusps grinding & mashing Molars cut like knives for biting Components of the Digestive System enamel crown (above gums) gingiva (gums) pulp (cavity) nerve endings periodontal membrane root dentin (under gums) root canal nerve artery vein Components of the Digestive System enamel Mouth i. Teeth: enamel: contains calcium makes it the hardest substance in the body caries: tooth decay in enamel (cavity) caused by: i) acids produced by bacteria ii) grinding dentin: bone-like substance surrounding pulp pulp cavity: contains nerves & blood vessels dentin pulp (cavity) root canal) caries Components of the Digestive System Teeth:(continued) pulpitis: tooth ache caused by inflammation of the pulp gingivitis: inflammation of the gums results in periodontal disease plaque: sticky film of bacteria & food between gums & teeth removed by flossing root canal: dentist removes infected pulp & sterilizes tooth keeps tooth alive Components of the Digestive System Organ Comments 1. Mouth opening to digestive system a) Teeth Function ingestion different shapes for tearing & grinding physical digestion Components of the Digestive System Organ Comments b) saliva made by 3 pairs of salivary glands secrete saliva into oral cavity Parotid gland Submandibular gland Sublingual gland Function contains: 1. water: to dissolve food 2. mucus: lubricates food (makes it slippery) 3. salivary amylase: enzyme which digests starch i.e. into mono & disaccharides . Components of the Digestive System Organ c) tongue Comments very strong muscle contains large numbers of taste buds bolus: ball of chewed food nerve endings Function 1.sensory: taste & temperature control 2. physical digestion: chewing & mixing food with saliva 3. swallowing: a.pushes bolus up & to the back of the pharynx b.causes epiglottis to block trachea 4. speech . Components of the Digestive System Organ Comments Function d) epiglottis flap of tissue at the base of the tongue above the trachea prevents food from going into lungs (down windpipe) to avoid choking 2) pharynx back of the throat common passageway for food & air . Components of the Digestive System Organ Comments 3) esophagus narrow tube about 30 cm long connecting pharynx to stomach contains 2 muscle layers which relax and contract rhythmically for peristalsis Function 1. leads food into stomach 2. ensures that food (bolus) is pushed into stomach (mucus glands help wave-like contractions lubricate the bolus) produced by circular & longitudinal muscles Components of the Digestive System . Components of the Digestive System Organ 4) cardiac sphincter Comments at the entrance of the stomach *sphincters: rings of muscles (open/close) heartburn: pain from splashing of gastric acid into the esophagus 5) pyloric sphincter pyloric sphincter at the end of the stomach cardiac sphincter Function closes during digestion to prevent backflow of gastric juice into esophagus closes during digestion to keep chyme (semidigested food) in stomach(2-3 hrs) opens to allow chyme to enter small intestine . Components of the Digestive System Organ Comments 6) stomach glands in lining make gastric juice containing: tough muscular bag (j-shaped) lined with 3 layers of muscles to churn & mix food with gastric juice Function 1. hydrochloric acid: a) physical digestion of fibrous tissue b) kills bacteria c) dissolves minerals d) converts pepsinogen into pepsin (active) ulcer: wound in the 2. pepsin: enzyme stomach lining which breaks down due to high acidity proteins into amino & low mucus acids 3. mucus: thick layer to chyme: semi-digested protect stomach wall food (very acidic) from acid & pepsin Components of the Digestive System cardiac sphincter duodenum pyloric sphincter oblique muscles circular muscles longitudinal muscles Components of the Digestive System glands in stomach lining ulcer in stomach lining ENDOSCOPE VIDEOS ACID REFLUX GASTRIC FOLDS STOMACH LINING & GASTRIC JUICE ENDOSCOPE VIDEOS STOMACH ULCER MULTIPLE STOMACH ULCERS Homework Page 212 Questions # 1-3 Page 214 Questions # 1-2,4-6 Page 216 Questions # 1-3