Chapter 31 Gastrointes坤 rEgulation and motility
1 Chapter 31 Gastrointestinal Regulation and Motility
Nutrition We require > carbohydrates(mainly glucose) proteins(essential amino acids) >fats(but Western diet fats too high) >vitamins >minerals Carbohydrate Intake(normally 3000 50 Protein 6000kcal per day depends on 15% Geography Fat 35% Occupation
2 We require: ➢carbohydrates (mainly glucose) ➢proteins (essential amino acids) ➢fats (but Western diet fats too high) ➢vitamins ➢minerals Nutrition Carbohydrate 50% Fat 35% Protein 15% Intake (normally 3000- 6000kcal per day & depends on Geography Occupation
Oral cavity Gastrointestinal T Sublingual salivary gland system Esophagus consists of Gastrointestinal (Gitract Gallbladder Accessory glandular organs Duodenun Large inte st ine Anal canal
3 Gastrointestinal system consists of Gastrointestinal (GI) tract Accessory glandular organs
Anatomy and functions of the entract GI tract Parotid salivary gland mouth, pharynx Mouth Sublingual salivary gland Pharynx esophagus, Trachea stomach, small intestine Submandibular salivary- glar Esophagus large intestine. anus Accessory glandular Stomach Organs Gallbladde Pancreas Small intestine salivary glands, liver Colon gallbladder, pancreas Cecum intestine Rectum Anus
4 Anatomy and functions of the GI tract GI tract mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus Accessory Glandular Organs salivary glands, liver, gallbladder, pancreas
Histology/organization of the Gut Wall From esophagus to anus, gi tract has the same basic arrangement of tissues There are 4 layers that can be distinguished Mucosa Submucosa Muscularis Serosa
5 Histology/organization of the Gut Wall From esophagus to anus, GI tract has the same basic arrangement of tissues. There are 4 layers that can be distinguished • Mucosa • Submucosa • Muscularis • Serosa
Layers of Alimentary Canal Submucosa Mucosa ircular muscle layer S eros Longitudinal muscle layer
6 Layers of Alimentary Canal Serosa Submucosa Mucosa Circular muscle layer Longitudinal muscle layer
Layers of Alimentary Canal Myenteric plexus Serosa Mucosa Submucosal plexus c Longitudinal Submucosa muscle Circular muscle
7 Serosa Mucosa Submucosa Longitudinal muscle Circular muscle Layers of Alimentary Canal Myenteric plexus Submucosal plexus
1. Digestion of food and absorption of nutrients are accomplished in a long tube connected to the r external world at both ends 2. Secretion and motility of the tube are major themes in understanding the gut
8 1.Digestion of food and absorption of nutrients are accomplished in a long tube connected to the external world at both ends 2.Secretion and motility of “the tube” are major themes in understanding the gut
Processing of food by the ds 1. Ingestion: process of eating 2. Propulsion: passing of food down the gi tract swallowing: voluntary peristalsis: reflex, involuntary, involves alternating contractions of muscles in body walls of Gi organs 3. Mechanical digestion prepares food for chemical digestion includes chewing, mixing with saliva by tongue action, churning in stomach
9 1. Ingestion : process of eating 2. Propulsion : passing of food down the GI tract • swallowing : voluntary • peristalsis : reflex, involuntary, involves alternating contractions of muscles in body walls of GI organs 3. Mechanical digestion • prepares food for chemical digestion • includes chewing, mixing with saliva by tongue action, churning in stomach... Processing of food by the DS
Processing of food by the DS 4. Chemical digestion catabolic steps in which food is broken down to basic building blocks accomplished by enzymes in digestive juices 5. Absorption: passage of food particles into the blood lymph 6. Defecation: elimination of indigestible food substances 10
10 4. Chemical digestion • catabolic steps in which food is broken down to basic building blocks • accomplished by enzymes in digestive juices 5. Absorption : passage of food particles into the bloodlymph 6. Defecation: elimination of indigestible food substances Processing of food by the DS