Digestive System Gabriela Torres Period 3
Digestive Process: Mouth to Esophagus
Digestive Enzymes
Digestive System
Major Organs of the Digestive System
The breakdown (digestion) and absorption of food for metabolism (energy and growth and repair of tissues)
Chemical Digestion: Breaks food into simpler chemicals that can be absorbed by cells in the body and works with the help of enzymes. For example: saliva
Absorption: Chemically digested foods moves from intestine into blood and lymph
Mechanical Digestion: Physical breaking of large food pieces into small pieces
Alimentary canal (GI Tract): Mouth, pharynx, esophagus, stomach, small intestine, large intestine
Accessory Organs: Teeth, tongue, salivary glands, liver, gallbladder, pancreas
Dissaccharides- Lactase -> glucose and galactose
Dissaccharides- Sucrase -> glucose and fructose
Dissaccharides- Maltase: glucose
Carbohydrates- Amalyse: poly -> di
Protein- Protease: peptide -> amino acids
Protein- Pepsin: protein -> peptide
The food enters the mouth, and is chewed (the tongue mixes the food with saliva and compacts it into bolus), chemical breakdown of carbohydrates (salivary amylase, main enzyme in saliva, digests starch and glycogen), and the pharynx and esophagus acts as a conduit to pass food from the mouth to the stomach
Layers of the GI Tract
1. Mucosa: Consists of mucous membrane , epithelium ( stratified squamos in mouth, esophagus and anus), lamina propria and muscularis mucosae
2. Submucosa: Consists of areolar connective tissue containing major blood vessel, and submucosal plexus
3. Muscularis Layer: Consists of two smooth muscle layers to allow for peristalsis and segmentation. Mouth, pharynx, superior esophagus, and anal sphincter-voluntary muscle
4. Serosa: Outer covering of the GI Tract and consists of serous membrane and produces serous fluid for lubrication
Disorders of the Digestive System
Jaundice: Yellow skin discoloration due to excessive amounts of bile in blood. The gallstone blocks the common bile duct causing feces to become white and skin to become yellow
Hepatitis/Inflammation of Liver: Due to hepatitis viruses or nonviral virus causes: drug toxicity, wild mushroom poisoning
Cirrhosis: Chronic inflammation of the liver usually resulting from alcoholism or chronic hepatitis