Ch 34 Flashcards
Incomplete Digestive System
Gastrovascular cavity - mouth only, with extracellular digestion
Complete digestive system
Alimentary canal - mouth to anus (one way food movement)
Organ specialization - grinding and storage, churning and digestion
Digestive Processes
Ingestion (Mechanical)
Digestion (Chemical)
Absorption and Elimination
Oral Cavity
The mouth (ingestion)
Salivary gland - lubricates and begins digestion
Lingual lipase released by tongue to break down triglycerides
Mammalian Teeth
Incisors, Canines, Premolars, Molars
Swallowing
Initiated - voluntary
Reflex - involuntary
Esophagus
Muscle tissue - Skeletal (1/3), Smooth (2/3)
Peristalsis
rhythmic contraction to move food/bolus through esophagus
Gastroesophageal sphincter
connects stomach and esophagus, to prevent stomach content from going back into esophagus
Stomach
Holding and churning, acidic breakdown, some absorption of alcohol, aspirin, and H2O
Gastric Juice
Exocrine gastric glands
Chyme, Goblet cells. Parietal cells. Chief cells
Chyme
gastric juice + digested food
Goblet cells
Mucus prevents self digestion of stomach
Parietal cells
HCl (ph2)
Intrinsic factor important for vitamin B12 absorption in small intestines
Chief cells
Pepsinogen (inactive) into pepsin (active)
Small intestine
Pyloric sphincter
Duodenum
Jejunum
Ileum
Villi
Microvilli
Pyloric sphincter
Stomach to small intestine
Duodenum
Chemical digestion is completed here
Pancreatic juice and biles salts released here
Jejunum
Absorption of sugars and amino acids
Ileum
Absorption of vitamins and bile salts
Villi
Absorption increases surface area
Microvilli
Cellular extension of villi
Epithelial digestion
Active sites with enzymes
Large Intestines
Colon (absorption)
Liver (bile pigments and salts)
Gall bladder (holds and concentrates bile)
Bile Salts (emulsifictation of fats)
Pancreas
Acini (secretory cells)
Carbohydrates
Major uses - Cell respiration, quick energy
Storage - liver, tubers
Proteins
Major uses - amino acids, antibodies and hormones, structure, transport
20 common amino acids (9 essential that can only be obtained through diet)
Lipids/Fats
Major uses - energy reserve, natural insulation, hormones, cell membrane
Essential fatty acids - polyunsaturated, monounsaturated, cholesterol
Digestive enzymes
Polysaccharides - salivary amylase, pancreatic amylase
Proteins - pepsin, trypsin, peptidase
Triglycerides - Bile salts, lipase
Obesity
Body mass index (BMI)
Causes - behavior, genetic, metabolic
