Digestive System Unit VIII

General Info Phases: Chemical Digestion Types: Mechanical Extracellular Intracellular Phases: Mechanical Chemical Poly-Tri-Di-Mono

All organs and related structures, in order. The Digestive Tract All organs and related structures, in order.

Oral Cavity Sensitive: pressure, pain, temp Palates: Top Soft & Hard

Tongue Bottom Initiates swallowing Positions food Contains nerve endings

Oral Cavity Cont. Taste buds: Solution to taste Sweet, Sour, Salty, Bitter Teeth: (32) Tearing & Chewing Tonsils

Salivary Glands 3 Pair: Parotid Submandibular Sublingual

Gland Info pH 6.7 950 - 1450 ml/24 hrs 99% water, 1% amylase ANS Lubricates food

Pharynx 3 Divisions: Naso Oro Laryngeal* Uvula

Laryngeal Pharynx Esophagus* Trachea: Glottis Epiglottis Larynx

Esophagus Behind trachea 8 - 10 inches long 2 muscle layers: Circular - inside Longitudinal - outside

Esophagus Cont. Mucous membrane lining: Lubricates Protects Peristalsis: Peristalic wave

Stomach Abdominal cavity (left) 3 Divisions: Fundus Body Pylorus

Muscle Layers Three layers: Longitudinal (outside) Circular (middle) Oblique (inside)

Sphincters Valve openings Two: Cardiac sphincter Pyloric sphincter

Special Tissues Peritoneum Mesentery: 2 Greater omentum Lesser omentum

General Info 950-1400ml Major function-Mechanical Gastric mucosa lining: Rugae Gastric glands*

Gastric Glands 35 million in adult Composed of 3 types of cells: Parietal=> HCl Chief=> enzymes Mucus=> mucus

Gastric Glands Cont. Gastric juice Gastrin

Parietal Cells pH 1-3, Dil 6 Destroys bacteria Dissolves salts Curdles milk

Parietal Cells Cont. Activates enzymes Distroys enzymes Breaksdown connective tissue Breaksdown protein “Perforated Ulcer”

Mucus Cells Produce mucin Protects mucosal lining

Chief Cells Coenzyme Pepsinogen (HCl) => Protease (protein) Prorennin => Rennin (protein)(curdles milk) Gastric lipase (fats)

Digestion Time Requirement Proteins 3-4 hours Carbo’s 1.5-2 hours

Small Intestine Most digestion-absorption Accessory organs: Liver Pancreas

General Info Enzymes from lining 1” Dia 20-21 ft long Three Divisions*

Divisions Duodenum 10 inches Jejunum 8 feet Ileum 12 feet

Muscles Layers Two layers: Longitudinal (outside) Circular (inside)

Villi 600X Enzymes: Peptidase, Sucrase, Maltase, Lactase, Lipase Lacteal

Liver Largest gland 3 pounds Upper right-abdominal cavity 3 lobes Produces bile*

Bile Composition: Bile salts (soaps)(Emulsion)(activates lipase) Unusable hemoglobin Bile pigment Cholesterol (gall stones)

Liver-Bile Cont. Hepatic duct Gall bladder “Common bile duct”

Pancreas Dual Gland Exocrine Gland Endocrine Gland

Exocrine Gland pH 7.5-8 Enzymes:* Trypsinogen, Amylase, Lipase Pancreatic juice

Enzymes Catalyst Specific Affected by: Temperature ph

Endocrine Gland “Insulin” Metabolism “Diabetes” Pancreatic duct Common bile duct

Large Intestine Colon Three divisions: Ascending Transverse Descending

Colon Cont. 2.5” Dia 5-6 ft long Two functions: Water & Electrolyte reabsorption Solid waste storage

Colon Cont. Cecum Appendix Ileocecal sphincter Sigmoid Rectum

Lipid Digestion Enzyme Action Place Gland Hydrolysis Stomach None None Bile* Liver Emulsification Sml Int Pancreas Sml Int Lipase Lipids Glycerol + Fatty Acids

Protein Digestion Place Gland Enzyme Action Stomach Gastric Sml Int Pepsinogen(HCl) Protease Polypeptides Dipeptides Stomach Gastric Sml Int Pancreas Trypsinogen(HCl) Trypsin Dipeptides Monopeptides Int Lining (Villi) Peptidase Sml Int Monopeptides Amino Acids

Carbo’s Digestion Place Gland Enzyme Action Salivary Amylase Mouth Polysaccharides Disaccharide's Salivary Amylase Mouth Destroys Amylase 15-30 Min. Stomach None “HCl”* Sml Int Pancreas Polysaccharides Disaccharide's Amylase Maltase Lactase Sucrase Disaccharide's Monosaccharide's Int Lining Villi Sml Int

The End!!!!!! Thank You