What do this picture and this video have in common? https://www.youtube.com/watch? v=H2zLvWeyiJY
Jan 19, 2016
What do this picture and this video have in common?
https://www.youtube.com/watch?v=H2zLvWeyiJY
Why do we eat?
The Digestive System performs a magical transformation…
The Digestive System performs a magical transformation…
The Digestive System performs a magical transformation…
The Digestive System performs a magical transformation…
Nutrients (Glucose, Proteins, Lipids, Nucleic Acids) Vitamins Minerals
Everything our bodies need to run (except for oxygen!)
The journey of food through our digestive system: a.k.a. the “Bite”taking Journey
Big Picture: Your gut is one long tube.
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Big Picture: Your gut is one long tube.
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Peristalsis: muscle contractions that move food through body
Big Picture: Your gut is one long tube.
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Peristalsis: muscle contractions that move food through body
Sphincters: valves that open and close to regulate digestion
4 Stages of Digestive System
1) Ingestion
2) Digestion
3) Absorption
4) Elimination
Finally, EAT YOUR DOUGHNUT HOLEMOUTH: STAGE 1: Ingestion STAGE 2: Digestion begins…
Mechanical vs. chemical
STOMACH
In 5 – 10 seconds: Your doughnut travels down the esophogus (due to peristalsis) to the…
This is a sphincter: STAGE 2: Digestion continues
M u s c le c h u rn s
Pep s in ( en z ym e t h a t b rea k s d o w n p ro t e in )
Hydrochloric Acid
STOMACH DIGESTION MECHANISMS
How do we know so much about the stomach?William BeaumontAlexis St. Martin
2 to 6 hours later…your doughnut will enter the SMALL INTESTINE Where… chemical digestion continues and absorption begins!
The SMALL INTESTINE is 20 feet long
The liver and pancreas release digestive enzymes into the top of the small intestine…. CHEMICAL DIGESTION!
Only happens in the VERY start of the small intestine
-- First 10 inches
5 ft and 2 inches remain for ABSORPTION
What enables quick and efficient absorption?
VILLIVein
carrying blood to
liver
VILLI
Capillaries
THE VILLUS
SURFACE AREA ENABLES SPEEDY ABSORPTION
Vein carrying blood to
liver
VILLI
VILLI
Capillaries
TEST YOUR UNDERSTANDING:
1) What structure feature of the small intestine makes it better suited for absorption than the stomach?
2) What theme of biology does this demonstrate?
3) How is your doughnut moving through small
intestine?
5 to 6 hours later…your doughnut will enter the LARGE INTESTINE or COLON
Absorption continues… and feces are produced in preparation for…
4 . EL IM INAT ION (12 TO 24 HOU RS L ATER )
BIOLOGY IS AMAZING!: YOUR MICROBIOME
Draw and label the path the doughnut is taking/will take through your body…
• Drawings should include: – 4 stages of digestive system and locations where they
occur– Vocabulary words– For each organ, 1 example of structure enabling
function
SEE PAGE 553 of LIVING WORLD FOR SUPPORT
FIRST: https://www.youtube.com/watch?v=_QYwscALNng