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Review Upper digestive tract – Oatmeal Cream Pies Comparative anatomy - Stomach Notes Small Intestine "No one can make you feel inferior without your consent." Eleanor Roosevelt. Title: Anat & Phys 3/9/07 . Class Topics. Objectives:. Thursday, January 2, 2020 6:14 AM.
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Review Upper digestive tract – Oatmeal Cream Pies Comparative anatomy - Stomach Notes Small Intestine "No one can make you feel inferior without your consent." Eleanor Roosevelt . Title: Anat & Phys 3/9/07 Class Topics Objectives: Thursday, January 2, 20206:14 AM
Class Assignments What By When • Comparative anatomy essay – cellulose digestion 3/13/07 • Due this class period • Due next class period • Due in the future
Upper digestive tract review • While eating do the following • 1st bite • Review the different types of teeth and think about their function as you chew • 2nd bite • Review the tongue and its many functions including moving food from side to side and taste • 3rd bite • Review the procedure for swallowing • 4th bite • Time 9 seconds after you complete swallowing to review esophagael function • Review what is occurring in the stomach to digest the “Oatmeal Cream Pie”
Comparative Anatomy“Cellulose Digestion” • Ruminants • Equine • Lagomorphs, rodents
Gastric Bypass Surgery • NIDDK web site Image taken from http://www.georgetownsurgical.com/procedure.html
Small Intestine • Microvilli increase surface area 60,000% • 6-8 m (around 20-25 ft) in length • diameter 2.5 - 4 cm • 90% of nutrient absorption • 3 regions • duodenum, jejunum, ileum
Small IntestineDuodenum • 25 cm long • mixing bowl • chyme - stomach • buffers - pancreas • mucus - mucosa • enzymes - pancreas • bile - gall bladder
Small IntestineJejunum • 2.5 m long • majority of nutrient absorption • many microvilli • increase surface area • Used to be surgically removed • drastic weight loss
From: http://www.agen.ufl.edu/~chyn/age2062/lect/lect_20/27_27.GIF
From: http://www.udel.edu/Biology/Wags/wagart/anaglyphpage/villi.gif From: http://www.ugc.edu.hk/rgc/english/documents/annua l_rpt98/html/english/case/d1_photo_a.htm
Small IntestineIleum • 3.5 m long • much lymph tissue • kill bacteria residing in large intestine • Ends at ileocecal valve
Pancreas • Primarily exocrine • drains into duodenum through duct of Wirsung (pancreatic duct) which joins with common bile duct • also enters via pancreatic accessory duct (duct of Santorini) • releases pancreatic juices • water, ions (bases)*, digestive enzymes* • *Inactive until reaching duodenum
From:http://faculty.southwest.tn.edu/rburkett/A&P2%20Digestive%20System%20Lab.htmFrom:http://faculty.southwest.tn.edu/rburkett/A&P2%20Digestive%20System%20Lab.htm
Pancreatic Enzymes • Carbohydrase • breaks down carbohydrates • Lipase • breaks down fats, oils, & waxes • Nuclease • Breaks down DNA & RNA • Protease & Peptidase • Breaks down proteins
Liver • Largest visceral organ • divided into two lobes • each lobe contains 100,000 hepatocytes • Hepatocyte functions • clean blood • store iron and other heavy metals • forms bile - sent to gallbladder • drug inactivation
From: http://faculty.southwest.tn.edu/rburkett/A&P2%20Digestive%20System%20Lab.htm
Digestive function of Hepatocytes • Carbohydrate metabolism • Lipid metabolism • amino acid metabolism • vitamin storage • fat soluble vitamins • A,E,D,K, B12 • Acquire nutrients directly from small intestine via hepatic portal vein
Gallbladder • Releases bile through common bile duct • guarded at the duodenum by sphincter of Oddi • Bile function • Break open lipids to lipase can digest • Bile salts are recycled by ileum • Gallstone - bile salt precipitates - block common bile duct
Hormones • Gastrin • Released by stomach • causes release of gastric juices and increases motility • released at sight, smell, or ingestion of food • Secretin • stimulates the release of buffers and water released into duodenum
Hormones • Cholecystokinen (CCK) • secreted when chyme hits duodenum • Releases sphincter of Oddi • Stimulates the production of pancreatic juices • inhibits gastric activity
Nutrient absorption • Carbohydrates (monosaccharides) • through microvilli to blood stream • facilitated diffusion • Proteins (amino acids) • through microvilli to blood stream • facilitated diffusion • Lipids (triglycerides) • through microvilli to lymph • diffusion - nonpolar substances
From: http://www.agen.ufl.edu/~chyn/age2062/lect/lect_20/digproc.gif