9.5 Digestion in the small and large intestine Flashcards
What happens in the small and large intestine
Food enters the small intestine from the stomach through the pyloric sphincter
The small intestine is about 2.5cm wide and up to 7m long.
Lipids, carbs and remaining proteins are digested in the small intestines
There are three components of the small intestine
3 parts of the small intestine
Duodenum, jejunum, and ileum
Duodenum
25-30cm, most enzymes are added and digestion continues.
Jejunum
Continued digestion, some nutrients are absorbed.
Ileum
majority of nutrients absorbed.
Villi in the small intestine
The small intestines is lined with Villi which are finger like projections to increase the surface area for digestion and absorption of nutrients
The villi have their own villi called Microvilli
Combined they increased the surface area 500 times
Villi contain capillaries inside to allow nutrients to enter the bloodstream
Role of the pancreas
The pancreas is located in between the duodenum and the stomach
It receives signals from the small intestine to secret enzyme for digestion
The small intestine also signals the pancreas ti from bicarbonate ions which are basic, neutralize chyme from the the stomach and prevent hard on the small intestines
Main enzymes released from the pancreas
Amylase, lipase, and trypsin
Amylase
Breaks down carbs into simple sugar
Lipase
Digest lipids into short fatty acid molecules
Trypsin
Digest proteins into amino acids
What does the liver do
The liver produces and secretes bile
Bile breaks down fats so lipases can digest them faster
What does the gallbladder do
The Gallbladder stores bile until food enters the duodenum
Bile gets excreted through the bile duct that connects the gallbladder to the small intestine.
4 parts of the large intestine
Cecum
Colon
Rectum
Anus
Cecum
Cecum is the beginning of the large intestine.
It is an open pouch collecting materials from the small intestine
