Digestive System

1
Digestive System
2
Digestive System

• Purpose
• To break down food into useable molecules to be
  carried to the
• cells via our
• blood

Digestive Pathway (Path the food travels)

• Mouth
• Esophagus
• Stomach
• Small Intestines
• Large Intestines

3
3 types of nutrients Carbohydrates -provide
quick energy -must be digested into their
simplest form/simple sugar
molecule -bun Fats/lipids -long term
energy -must be digested -cheese and in red
meat Protein -build and maintain our cells
and tissues -must be digested down into
individual amino acids -cheese and red meat
4
Digestive Pathway..where food travels through.

• Mouth-teeth physical digestion of all food types.
  
• 2) Salivary glands
• Produce saliva
• Empties into mouth
• Under the direction of your brain
• -how commercials work
• Produces the enzyme amylase
• Responsible for the chemical digestion of
  carbohydrates

3) Pharynx Back of throat area Common passage
for -food and air No digestion occurs
5
Digestive System

• 4) Esophagus
• Passageway for food from mouth to stomach
• No digestion
• peristalsis Wave-like motion that pushes food to
  stomach animation
• 5) Cardiac Sphincter
• End of esophagus, beginning of stomach
• Ring of muscle
• Keeps food moving in 1 direction
• What is heart burn?
• if food moves back into esophagus from
• sphincter. Contains acid from stomach

6
Digestive System

• 6) Stomach
• Muscular sac which digests proteins
• Physical digestion in form of churning
• Chemical digestion in form of HCl, gastrin
  pepsin to break down proteins
• Special lining to protect from acid sore in
  this lining can lead to an ulcer
• Chyme- undigested foodenzymeacid mixture.

7
Digestive System

• 7) Pyloric Sphincter
• Ring of muscle which keeps food moving from
  stomach to sm. intestine
• 8) Small Intestine
• 20-21 ft. long
• 3 sections
• Duodenum 1st 10 inches, carries chyme to
  jejunum, is were all enzymes from pancreas and
  gall bladder empty into
• Jejunum 8 feet, carbs, proteins, lipids
  digestion were food molecules are absorbed into
  blood
• Ileum 13 feet, takes undigested material to
  large intestine
• Has villi

8
Villi in Small Intestine
-Villi increases surface area of small intestines
so more food can be absorbed into the blood
faster.
9
Digestive System

• 9. Large Intestine/colon
• larger in diameter
• 3 ft. long
• - removes excess water for undigested matter
• too much water absorbedconstipation
• too little water absorbeddiarrhea
• 10. Rectum Anus
• holds solid waste until expelled (rectum)
• exit (anus)

10
animation
11
Organs part of the digestive system BUT not part
of the digestive pathway.
12
1. Appendix

• Appendix-
• No apparent function in humans
• In other mammals, it helps to
• digest plant materials/cellulose
• animation

13

• 2. Liver
• Largest internal organ
• Filters ammonia out of blood and converts it into
  urea
• Makes bile
• 3. Gall bladder
• Stores bile for the digestion
• of lipids, empties into
• sm. Intestines via common
• bile duct.
• 4. Pancreas-
• makes and delivers the
• following to small intestines
• pancreatic amylase- carbs
• lipase-lipids
• trypsin- proteins
• sends these enzymes to small intestine
• through the pancretic duct.
• Sodium bicarbonate
• -is a base, neutralizes HCl so it does not damage
  small intestines.

14
To Digest

• Ingest
• Chew 10 to 30 times
• Swallow 4 to 8 seconds
• Churn 2 to 4 hours
• Absorb 3 to 5 hours
• Compact 10 hours to several days!
• Eliminate

15
The end.
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
Digestive Problems

• Acid reflux
• Ulcer

20
Gall stones Made up of bile salts and
cholesterol Appendicitis
21

• Diverticulitis
• Hemorrhoids