4 ­ ANIMALS fix up The Large Intestine.notebook
January 08, 2016
The Large Intestine
Location: Abdominal Cavity (surrounding your small intestine)
Physical description: ­ a 1.5 metre­long tube ­ has an average diameter of 5 cm. ­ has six distinct regions leading from the join with the small intestine: * caecum * ascending colon * transverse colon * descending colon * sigmoid colon * rectum.
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4 ­ ANIMALS fix up The Large Intestine.notebook
January 08, 2016
The Large Intestine
The primary functions of the large intestine are ... • absorb water (by drying out indigestible food) • convert food waste products into solid waste (feces)
for elimination • store food residues until they can be excreted 2
4 ­ ANIMALS fix up The Large Intestine.notebook
January 08, 2016
The Large Intestine
Mechanical Digestion:
Mechanical digestion in the large intestine involves making mucus which is important in easing the passage of waste products towards the rectum and anus. Propulsion along the large intestine is much slower than the small intestine. Movement can take days rather than hours (travels at about 1cm per hour). Chemical Digestion:
Chemical digestion is not significant the large intestine .
However, billions of anaerobic bacteria inhabit the colon, where they ferment dietary fibre and other unabsorbed substances.
Some of these bacteria produce important vitamins, including folic acid, several B vitamins, and vitamin K which are absorbed through the blood stream
Why do we burp and fart?
https://www.youtube.com/watch?v=3CVoTfcdd4w
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4 ­ ANIMALS fix up The Large Intestine.notebook
January 08, 2016
The Large Intestine
Absorption of nutrients:
About 90% of water is absorbed back into the blood and extracellular fluids The volume of the indigestible food matter (mostly undigestible plant matter) is reduced by about two thirds
Other Facts:
Food residues may remain in the colon on average about 30 hours, and there are a lot of bacteria. The amount of bacteria varies depending on diet and use of antibiotics but can make up more than half of the weight of fecal material.
(Gum does not stay in your system for 7 years!)
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4 ­ ANIMALS fix up The Large Intestine.notebook
January 08, 2016
Digestive Structures and Their Primary Function.
Digestive Structure
Primary Function
Mouth
Esophagus
Stomach
Small intestine
Large intestine
Transport (swallowing)
Water absorption
Mechanical and chemical digestion
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4 ­ ANIMALS fix up The Large Intestine.notebook
January 08, 2016
A Cow's Digestive System
https://www.youtube.com/watch?v=svw5KA8YlAA
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