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Digestive System. J. Hinson Human Anatomy and Physiology. http://connection.lww.com/products/stedmansmedict/primalpictures.asp. I. Introduction. Digestion Includes Alimentary Canal (aliment/o = nourish) : mouth, pharynx, esophagus, stomach, small intestine, large intestine
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Digestive System J. Hinson Human Anatomy and Physiology http://connection.lww.com/products/stedmansmedict/primalpictures.asp
I. Introduction • Digestion • Includes • Alimentary Canal (aliment/o = nourish) : mouth, pharynx, esophagus, stomach, small intestine, large intestine • Accessory Organs: salivary glands, liver, gallbladder, pancreas http://wps.prenhall.com/wps/media/objects/488/500694/CDA40_1.jpg
II. The Alimentary Canal • Muscular tube ~ 9 m • Tissues • Mucosa • Glands secrete • Functions: protection, absorption and secretion • Submucosa • Contains blood vessels, lymphatic vessels, and nerves • Nourishes
II. The Alimentary Canal B. Tissues 3. Muscular a. circular smooth muscle controls diameter; longitudinal controls length 4. Serosa a. visceral peritoneum b. contains serous fluid C. Movements: mixing or propelling - peristalsis http://medsci.indiana.edu/c602web/602/c602web/scans/19f.jpg
III. Oral Cavity • Mouth (or/o): mechanical digestion • Cheeks (bucc/o): muscular for expression and chewing • Lips (cheil/o): movement and sensation; color from blood vessels
III. Oral Cavity D. Tongue (lingu/o; gloss/o): mixes food w/ saliva • Connects via frenulum • Papillae contain taste buds (bitter, sweet, sour, salty) http://content.answers.com/main/content/img/galeNeurology/gend_01_img0040.jpg http://health.yahoo.com/media/healthwise/n5551320.jpg
III. Oral Cavity E. Palate (palat/o) 1. anterior – hard posterior – soft projection is the uvula (uvul/o) 2. palatine tonsils – lateral 3. pharyngeal (pharyg/o) tonsils - posterior http://biology.clc.uc.edu/fankhauser/Labs/Microbiology/Strep_Detection/oropharynx_P2253089_lbd.JPG
III. Oral Cavity F. Teeth (dent/i; dont/o; odont/o) 1. 20 primary (deciduous); 32 secondary (permanent) 2. increase surface area 3. Types: a. incisor (front) b. cuspids (canines) c. bicuspids d. molars 4. Consists of: crown, root, enamel, dentin, pulp 5. peridontal ligament attaches http://www.dentalgentlecare.com/_derived/tooth_anatomy.htm_txt_Tooth2.gif
IV. Pharynx(pharyng/o) • Cavity behind mouth (aka – throat) • Nasopharynx • Oropharynx • Laryngo-pharynx http://www.levelfive.com/ZINA/IMAGES/Anatomical/pharynx.jpg
V. Swallowing • Three Stages • Food is mixed with saliva; forms a bolus; forced into the phayrnx – voluntarily initiated! • Involuntary reflex moves food to esophagus; epiglottis (skin flap) closes • Food to stomach via peristalsis. http://greenfield.fortunecity.com/rattler/46/upali4.htm
VI. Esophagus(esophag/o) • Collapsible tube ~ 25 cm 1. Penetrates diaphragm • Circular smooth muscle http://home.hawaii.rr.com/dochazenfield/images/esophagus%20B.jpg
VII. Stomach (gastr/o) • General Info • J-shaped, pouch-like, organ in upper L abdomen • Holds ~ 1 L • Folded rugae • Mixes bolus w/ HCl and gastric juice to become chyme http://www.sciencebob.com/lab/bodyzone/stomach.gif
VII. Stomach 5. Pyloric a. Pyloric sphincter prevents regurgitation B. Regions • Cardiac • Fundus • Body • Antrum http://training.seer.cancer.gov/module_anatomy/images/illu_stomach.jpg
VII. Stomach C. Gastric Secretions • Glands secrete juice • Goblet – mucus • Chief – enzymes • Parietal – HCl Acid • Gastric Juice • Regulated by gastrin • food inhibits secretion D. Begin protein digestion; Some absorption: H20, glucose, salts, alcohol, lipid-soluble drugs http://intmed.muhealth.org/gast/images/stomach.gif
VIII. Small Intestine (enter/o) • Extends from pyloric sphincter to LI • Functions: • Receive secretions • Completes digestion in chyme • Absorbs nutrients • Transports wastes to LI http://www.exn.ca/news/images/1999/02/01/19990201-smallintestine.jpg
VIII. Small Intestine C. 3 portions • Duodenum • Jejunum • Ileum a. Mesentery suspends
VII. Small Intestine D. Secretions • Include mucus and enzymes • Split macromolecules • Peptidases: proteins to amino acids • Sucrase/maltase/lactase: disaccharides to monosaccharides • Lipase: lipids to fatty acids and glycerol • Enhanced by gastric juices, chyme, and distension http://bio.bd.psu.edu/cat/Circulatory_System/vesels%20of%20small%20intestine.jpg
VII. Small Intestine E. Absorption • Villi increase SA • Monomers absorbed via diffusion or active transport • Also water and electrolytes • Malabsorption • Bile problems; Celiac disease – gluten reaction • Sxs: weakness, etc. http://publications.royalcanin.com/images/2/2343/p7_image.gif
IX. Large Intestine (col/o) • ~ 5 feet • Cecum • Appendix • Colon • Ascending • Transverse • Descending • Sigmoid
IX. Large Intestine A. 1. c. Rectum: ~ 5 cm d. Anal canal: ~ 2-3 cm (i) anus (a) internal (b) external (ii) hemorrhoids http://www.nutrigenesis.com/page_images/hemorrhoids.jpg
IX. Large Intestine C. Functions 1. no digestive function 2. mucus secretions 3. absorbs water and electrolytes 4. forms, stores, and expels feces
http://mi2mm00.eng.shizuoka.ac.jp/matsumaru2/research/21c-valsalva.jpghttp://mi2mm00.eng.shizuoka.ac.jp/matsumaru2/research/21c-valsalva.jpg IX. Large Intestine D. Movement 1. Mixing and peristalsis 2. 2-3 movements daily 3. Defecation (initiated by distension) a. valsalva maneuver E. Feces 1. Composition: 75% water, undigested material, mucus, & bacteria 2. bile salts
Colonoscopy Ostomy http://www.youtube.com/watch?v=kUvHDdjZJkc http://www.youtube.com/watch?v=rl4s1D4MGH8 http://www.dhmc.org/dhmc-internet-upload/file_collection/colonscopy.jpg
X. Salivary (sial/o) Glands 3 • Function of fluids: • Moisten food particles • Bind • Dissolve carbs • Dissolve chemicals for taste • Cleansing • Cells: • Serous – secrete salivary amylase to break down carbs • Mucous – mucus to bind and lubricate 1 3 2 http://www.salivary-glands-disease.com/assets/images/imgSGDcauses.jpg
XI. Liver (Hepat/o) • Below diaphragm • Functions: • Metabolism of macromolecules • Storage – vitamins A, D, B12 • Filtering blood • Destruction of toxins (alcohol) • Secretion of bile http://www.livercancer.com/images/anterior.liver.gif
IX. Liver C. Structure • Reddish-brown color • Lobes a. Separated into hepatic lobules • Hepatic ducts carry bile a. Common bile duct (cholagi/o) formed by merging http://www.liverdoctor.com/images/detox_pathways.jpg
IX. Liver D. Bile (chol/e,o) • Secreted by hepatic cells • Contains bile salts, pigments, etc. a. bile salts digest http://www.pathguy.com/lectures/fatty_liver.jpg http://www.pathguy.com/lectures/liver.htm
XII. Gallbladder (cholecyst/o) • Attached to liver by cystic duct • Functions: • Stores bile • Concentrates bile • Release bile • Lipid absorption a. emulsification http://www.lbah.com/images/liver/gallbladder.jpg
X. Gallbladder C. Common Bile Duct = cystic + hepatic ducts D. Gallstones = choleliths! http://www.emedicine.com/med/images/1226gs1.jpg http://images.medicinenet.com/images/illustrations/stomach.jpg
XIII. Pancreas (pancreat/o) • Both endocrine and exocrine function • Structure • Extends horizontally • Pancreatic duct and Bile duct from liver and gallbladder empties into duodenum http://training.seer.cancer.gov/module_anatomy/images/illu_pancrease.jpg
XIII. Pancreas (pancreat/o) • Pancreatic juice • Contains enzymes that can split carbs, proteins, fats, and nucleic acids • Regulation • Secretin stimulates release of pancreatic juice high in bicarb. • Cholecystokinin stimulates release of pancreatic juice high in digestive enzyme. http://training.seer.cancer.gov/module_anatomy/images/illu_pancrease.jpg
VIII. Pancreas (pancreat/o) • Islets of Langerhans (endocrine cells) secrete: • Insulin: stimulates body cells to take in glucose from the blood stream to decrease blood sugar levels • Damage or underproduction: hyperglycemia and/or Diabetes Mellitus (DM) • Overproduction: hypoglycemia • Glucagon: stimulates liver to release glucose to increase blood sugar levels
XIV. Clinical Terms • Aphagia • Cholecystitis • Cirrhosis • Diverticulitis • Dyspepsia • Gingivitis • Hepatitis • Diabetes http://www.dental-health-index.com/images/Ging1.jpg