Digestive system (gastrointestinal, GI tract) Anatomy: Mouth (oral cavity) teeth, tongue, salivary glands Throat Throat pharynx, epiglottis (part of the larynx that closes off the trachea to lungs)
Digestive system (gastrointestinal, GI tract) Anatomy: Mouth Throat Esophagus = tube that connects pharynx to the stomach (about 10 in.) Stomach Small intestine large intestine, colon rectumanus
Digestive system (gastrointestinal, GI tract) ingestion= food entering the mouth chewing=mastication or crushing food digestion = chemical breakdown of foods secretion = acids, buffers, enzymes and H2O aids in breakdown of food absorption = broken down food is absorbed into the blood stream and lymph system excretion = waste products are eliminated from the body
Digestive system (gastrointestinal, GI tract) Oral cavity Teeth: enamel-hardest substance in the body 20 baby (deciduous) & 32 adult w/wisdom, 8 Incisors, 4 cuspid, 8 premolars & 12 molars (3 rd molar wisdom) 20 baby (deciduous) & 32 adult w/wisdom, 8 Incisors, 4 cuspid, 8 premolars & 12 molars (3 rd molar wisdom) tongue (aids in mastication) salivary glands – 3 pairs
Digestive system (gastrointestinal, GI tract) Stomach located on the left side of abdominal cavity, under the diaphragm and covered almost completely by the liver approximately 10 inches long, diameter varies depending on the amount ingested, can expand due to folds temporary holding area for food, secrets gastric acid & enzymes
Digestive system (gastrointestinal, GI tract) Stomach Regulates the rate, partially digested food enters the small intestine absorbs small amounts of water and other substances-very limited takes about 4 hours to empty after a meal liquids and carbohydrates pass through quickly, protein a little more time, fats take the longest
Digestive system (gastrointestinal, GI tract) Pyloric sphincter Duodenum - first section in the small intestine inches long Jejunum - middle section in the small intestine 8ft Ileum -last section 6-12 ft long, attaches to the large intestine