The small intestine is responsible for digestion of proteins, fats and carbohydrates. It also absorbs most nutrients.
However, the large intestine is less active in it's processes. The large intestine only digests fiber and only absorbs water.
Absorption
Although the stomach is responsible for digestion, very little absorption happens in it. Instead, the stomach is more like a washing machine; it agitates foodstuffs. It stirs up ground up food (mechanical digestion from teeth / gums occurs in the mouth), with stomach acids in the stomach and bile salts from the gallbladder assisting in chemical digestion.
In the Stomach, or Intestines (Look a little deeper), there is some bacteria that helps with digestion, because they speed up the process. The Immune System recognizes this, and basically leaves them to do their job.
Hydrogen is absorbed from the intestines and carried by the bloodstream into the lungs where it is exhaled. Normally there is very little hydrogen detectable in the breath, so its presence indicates faulty digestion of lactose.
pinkish and little red
Without the small intestines, there would be malabsoption problems. The person would get little nutrients or vitamins. The person would need to take vitamin pills and other minerals to sustain life.
little worms that eat ur intestines no joke!
The gall bladder is a little sack on the bottom of the liver. The liver produces bile, an enzyme used in digestion, then pumps the excess bile into the gall bladder to be stored. When the bile is needed in the intestines the bile is pumped out of the gall bladder through the common bile duct.
Gastric caeca are finger-like projections found in the digestive system of some animals, such as insects and crustaceans. They are located at the junction of the foregut and midgut and play a role in digestion and absorption of nutrients. Gastric caeca increase the surface area available for enzymatic activity and nutrient absorption, aiding in the efficient digestion of food.
I've heard that there are little hair like things that suck the nutrients out of the food inside the intestines. They are called villi. They are finger like structures that collect all the nutrients that have been collected before entering the small intestine!
The large intestine primarily absorbs water and electrolytes from undigested food, with little to no involvement in chemical or mechanical digestion. Its main role is to form and store feces before they are eliminated from the body.
Fiber