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NOTES – DIGESTIVE SYSTEM ANATOMY
Interesting Digestive System Facts
After you eat how long does
it take for the stomach to
empty?
Within 2-6 hours, all food is
emptied into the small
intestine.
How many
pounds of food
does the
average person
eat in a year?
1,100
How many feet long are your
intestines?
about 20-30 ft long.
NOTES – DIGESTIVE SYSTEM ANATOMY
• Oral Cavity
• mouth, pharynx, esophagus
• MOUTH
• SALIVARY GLANDS – produce saliva
• Saliva Components
• Mostly water – about 99.5%
• SALIVARY AMYLASE – digests starch
• LYSOZYME – antibacterial action
• MUCIN – lubricant
• chewing and saliva with food form a
BOLUS
• PHARYNX
• common area for food and air
• Epiglottis
• prevents food from entering the
trachea (wind pipe)
• ESOPHAGUS
• transports bolus from pharynx to
stomach
• involuntary muscular movement of
food - PERISTALSIS
• STOMACH
• a storage & mixing chamber
• secretions
• mucus
• hydrochloric acid (HCl)
• HCl activates pepsinogen to pepsin
which is main enzyme that digests
protein
• movement
• mixing waves - peristalsis
• bolus becomes chyme
• SMALL INTESTINE
• parts: duodenum, jejunum, ileum
• Function:
• digestion and absorption
• intestinal juice – water & mucus
• epithelial cells have digestive
enzymes to digest ALL classes of
food
• LIVER
• performs many functions – main
blood filter in digestive system
• in digestion it secretes BILE into
the gall bladder
• the gall bladder then dumps bile
into small intestine
• bile EMULSIFIES fats – breaks fat
into smaller pieces – easier for fat
digesting enzymes to do their work
Normal liver
fatty liver
Cirrhosis of the liver
• PANCREAS
• pancreatic enzymes are important for
the digestion of all major classes of food
• four enzymes and bicarbonate
• all are dumped into small intestine
• LARGE INTESTINE
• Parts: ascending colon,
transverse colon, descending colon,
sigmoid colon
• chyme is converted to feces
• absorption of water & salts
• E. coli bacteria synthesizes
vitamin K