Digestive Organs

The digestive system is composed of accesory components and major organs.

The accessory structures are:

• Teeth-aide in mastication, performing mechanical digestion.
• Salivary Glands- secrete salivary amylase, which breaks downs starches into monosaccharides and disaccharides. It also helps to moisten food and aid in bolus formation.
• Tongue-moves food around in the mouth to help form a bolus. Propels the bolus toward the back of the mouth.
• Gall Bladder-stores bile produced by the liver, and releases it when necessary.
• Esophagus-

The major organs of the digestive system are:

Stomach-

• Grinds food via peristalsis (muscle contractions that pushes food further down the GI tract) and segmentation (mixing the contents of the stomach by 1/2s, allowing for the mixing of molecules and enzymes).
• Carbohydrate digestion.
• Digests proteins with peptidases.
• Creates chyme (food now transformed into a liquid form).

Small Intestine-

• Finishes digestion.
• Performs virtually ALL nutrient absorption.

Large Intestine-

• Reclaims (reabsorbs) water, vitamins, and electrolytes.
• NO Digestion.
• Parts of the Large Intestine: (1) Cecum (appedix found attached to this), (2) ascending colon, (3) transverse colon, (4) descending colon, (5) sigmoid colon.

Liver-

• Bile production
• Detoxification
• Storage of fat-soluble vitamins.
• Processes blood-borne nutrients (from the hepatic portal vein).

Pancreas-has both endocrine and exocrine functions.

• Endocrine = secrete insulin and glucagon.
• Exocrine = secrete enzymes that digest ALL forms of food.