Review

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Class Topics
Title Anat Phys 3/9/07
Objectives

• .

• 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

Thursday, November 5, 2020 1147 AM
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Class Assignments
By When
What

• Comparative anatomy essay cellulose
  digestion 3/13/07
• Due this class period
• Due next class period
• Due in the future

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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

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Comparative AnatomyCellulose Digestion

• Ruminants
• Equine
• Lagomorphs, rodents

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Gastric Bypass Surgery

• NIDDK web site

Image taken from http//www.georgetownsurgical.com
/procedure.html
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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

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Small IntestineDuodenum

• 25 cm long
• mixing bowl
• chyme - stomach
• buffers - pancreas
• mucus - mucosa
• enzymes - pancreas
• bile - gall bladder

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Small Intestine Jejunum

• 2.5 m long
• majority of nutrient absorption
• many microvilli
• increase surface area
• Used to be surgically removed
• drastic weight loss

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From http//www.agen.ufl.edu/chyn/age2062/lect/l
ect_20/27_27.GIF
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From http//www.udel.edu/Biology/Wags/wagart/anag
lyphpage/villi.gif
From http//www.ugc.edu.hk/rgc/english/documents/
annua l_rpt98/html/english/case/d1_photo_a.htm
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From http//www.pathology.vcu.edu/education/gi/la
b2.a.html
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Small Intestine Ileum

• 3.5 m long
• much lymph tissue
• kill bacteria residing in large intestine
• Ends at ileocecal valve

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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

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Fromhttp//faculty.southwest.tn.edu/rburkett/AP2
20Digestive20System20Lab.htm
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Pancreatic Enzymes

• Carbohydrase
• breaks down carbohydrates
• Lipase
• breaks down fats, oils, waxes
• Nuclease
• Breaks down DNA RNA
• Protease Peptidase
• Breaks down proteins

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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

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From http//faculty.southwest.tn.edu/rburkett/AP
220Digestive20System20Lab.htm
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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

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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

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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

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Hormones

• Cholecystokinen (CCK)
• secreted when chyme hits duodenum
• Releases sphincter of Oddi
• Stimulates the production of pancreatic juices
• inhibits gastric activity

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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

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From http//www.agen.ufl.edu/chyn/age2062/lect/l
ect_20/digproc.gif
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