The digestive system consists of an alimentary canal and several accessory organs. The Digestive System
The Digestive System The digestive system mechanically and chemically breaks down food. Mechanical digestion includes chewing and peristalsis. Chemical digestion includes the use of enzymes.
The Digestive System Digestion = Big Little Food Nutrients Nutrients = carbohydrates sugars fats fatty acids + glycerol proteins amino acids
Essential nutrients are absorbed into the body and the unused waste material is excreted out of the body. The Digestive System
The Alimentary Canal The Digestive System
The Alimentary Canal Wall Layers Mucosa Structure: composed of epithelial, connective, and smooth muscle tissue; mucus secreting glands present Function: protection, absorption, secretion The Digestive System Submucosa Structure: composed of loose connective tissue; glands, blood and lymph vessels present Function: nourishment
The Digestive System The Alimentary Canal Wall Layers Muscular layer Structure: composed of 2 layers of smooth muscle; circular and longitudinal shaped fibers Function: movement Serosa Structure: composes the outer layer of the canal Function: secretion of fluid to lubricate so tube can slide feely
The Oral Cavity The Digestive System
The Teeth The Digestive System
The Pharynx The Digestive System
The Salivary Glands The Digestive System
VIII. The Stomach The Digestive System
The Small Intestine The Digestive System
The Large Intestine The Digestive System
The Liver The Digestive System
The Digestive System The Gall Bladder and Pancreas
Overview Salivary Glands (amylase) Oral Cavity Esophagus Pancreas (lipase, amylase, trypsin, chymotrypsin, carboxypeptidase) Gall Bladder/Liver (bile) Stomach (HCL and pepsinogen = pepsin) Small Intestine (peptidase, lipase, sucrase, maltase, lactase) Large Intestine Blood (fatty acids, glycerol, amino acids, monosaccharides) Blood (water, electrolytes, vitamins) Rectum
The Digestive System Digestion = Big Little Food Nutrients Nutrients = carbohydrates sugars fats fatty acids + glycerol proteins amino acids
Chemical Digestion and Nutrients Carbohydrates Uses in the Body: used primarily to supply energy for cellular processes
Chemical Digestion and Nutrients Carbohydrates Dietary Sources: - starch from grains and vegetables - glycogen from meats - monosaccharides from honey and fruits Dietary Requirements: - Varies among individuals - Depends on amount of physical activity, body size and metabolic rate.
Chemical Digestion and Nutrients Carbohydrate Digestion (starch to monosaccharide) Pancreas Chemical digestion by pancreatic amylase Mouth Mechanical digestion Chemical digestion by salivary amylase Stomach Mechanical digestion Small Intestine Chemical digestion by sucrase, maltase + lactase Small Intestine Glucose absorbed into blood
Chemical Digestion and Nutrients Lipids Uses in the Body: -supplies energy for cellular processes and for building cellular structures
Chemical Digestion and Nutrients Lipids Dietary Sources: - saturated fats found in meats, eggs and milk - unsaturated fats found in seeds, nuts and plant oils - monosaturated fats found in olive, peanut and canola oils Dietary Requirements: - Recommended to be less than 30% of total calories - Depends on amount of physical activity, body size and metabolic rate.
Chemical Digestion and Nutrients Lipid Digestion (fat to glycerol + fatty acid) Pancreas Chemical digestion by pancreatic lipase Liver/ Gall Bladder Mechanical digestion by bile Mouth Mechanical digestion Stomach Mechanical digestion Small Intestine Chemical digestion by intestinal lipase Small Intestine Glycerol and fatty acids absorbed into lymph
Chemical Digestion and Nutrients Proteins Uses in the Body: - enzymes, clotting factors, keratin of skin and hair, collagen of connective tissue, plasma proteins, muscle proteins, hormones and antibodies.
Chemical Digestion and Nutrients Protein Dietary Sources: - meats, fish, poultry, cheese, eggs and cereals Dietary Requirements: - Between 60 to 150 grams per day - Depends on amount of physical activity, body size and metabolic rate.
Chemical Digestion and Nutrients Protein Digestion (protein to amino acids) Pancreas Chemical digestion by trypsin, chymotrypsin + carboxypeptidase Mouth Mechanical digestion Stomach Mechanical digestion Chemical digestion by HCl acid and pepsin Small Intestine Chemical digestion by peptidase Small Intestine Amino acids absorbed