Introduction to Medical Careers Digestive System Chapter 16

Learning Objectives Define at least 10 terms relating to the digestive system Describe the four functions of the digestive system Identify different structures of the digestive system and their functions Identify the location and function of three accessory organs of the digestive system Describe at least five disorders of the digestive system

Vocabulary: Chapter 16 Bile Bolus Chyme Deglutition Emesis Endoscopy Enema Flatulence Ingestion Jaundice Mastication Peristalsis Sphincter Villus

FACTS approx. 30 feet long unsterile- open at both ends also called the ‘gastrointestinal system’

Functions Transportation of food & waste Physical & chemical breakdown of food physical=chewing, chemical=saliva Absorption of digestive food Nutrients your body wants Final elimination of waste Maintain proper balance of water

Organs Mouth Teeth Tongue Saliva bite and chew food (mastication) tastes, chews & swallows food Saliva enzymes breakdown food

tube like structure,transports food from mouth to stomach via this Esophagus peristalsis- wave like contraction by which food is moved tube like structure,transports food from mouth to stomach via this

Stomach Sac like muscular organ Squeezes & churns food to continue physical breakdown Protein digestion begins Some items absorbed into blood (alcohol, glucose, drugs) 1-4 hours to empty into small intestine

Small Intestine 23 feet long Longer in length and smaller in diameter 3 parts Duodenum, Jejunum & Ileum Continued secretion of enzymes to breakdown food Most absorption occurs here carbs, fats, proteins Villi increase absorption area

Duodenum, Jejunum & Ileum Lined with villi Fully breaks down food to nutrients to send into bloodstream Transports the mixture to large intestine

Large Intestine 3 parts Absorbs into blood ascending colon transverse colon descending colon Absorbs into blood Water Vitamins Electrolytes

https://www.youtube.com/watch?v=b20VRR9C37Q

Food Journey (Anywhere from 3 hours to 3 days) Starts in mouth Through esophagus to stomach Stomach to Small Intestine (Duodenum to Jejunum to Ileum) Large Intestine (Ascending colon to Transverse to Descending) Out

Table 16-1 Digestive System

Accessory Organs of the Digestive System Three accessory organs that aid in the process of food breakdown Pancreas Exocrine and endocrine functions Produces pancreatic juice which helps break down food Insulin & Glucagon: help regulate carbohydrate metabolism

Accessory Organs of the Digestive System Three accessory organs that aid in the process of food breakdown Liver Produces bile to assist in digestion of fat Converts glucose to a storage form Stores the fat-soluble vitamins (A, D, E, and K) Gallbladder Stores bile until it is needed in the small intestine

Assessment Techniques Radiography Uses barium to allow structures to show esophagus, stomach, and small intestine Endoscopy Flexible tube inserted into body cavities Gastric analysis A nasogastric tube is used to remove stomach contents Fecal analysis Examination of stool specimen for presence of microorganisms or blood Palpation and auscultation Feeling the abdomen and listening for bowel sounds

Figure 16-3 Endoscopy

Disorders of the Digestive System Alactasia Also called “lactose intolerance.” Not enough of the enzyme lactase is produced. The unabsorbed lactose ferments in the intestines leading to gas, cramps, and diarrhea. Appendicitis Inflammation of the appendix Cholecystitis Inflammation of the gallbladder

Disorders of the Digestive System (Continued) Cirrhosis A chronic degenerative condition of the liver accompanied by the formation of scar tissue Colon cancer An abnormal growth in the large intestine Constipation The inability to defecate Crohn’s disease Inflammation and ulceration, usually affecting the ileum or colon, or both

Disorders of the Digestive System (Continued) Diarrhea The passage of frequent and watery stools Diverticulitis The weakening of the colon, leading to formation wall of a pouch, causing infection or abscesses if fecal material trapped Food poisoning Illnesses transmitted by food

Disorders of the Digestive System (Continued) Gastritis Inflammation of the stomach lining Gastroesophageal reflux disease Frequent heartburn or chest pain, bitter taste in the mouth, difficulty swallowing, frequent hoarseness or coughing Halitosis Or bad breath, is caused by anaerobic bacteria

Disorders of the Digestive System (Continued) Heartburn A painful burning sensation in the esophagus caused by the backflow of acidic chyme from the stomach Hemorrhoid A painful dilated vein in the lower rectum or anus Hepatitis A viral infection of the liver

Disorders of the Digestive System (Continued) Mumps A highly contagious viral infection of the parotid glands Pancreatitis A mild acute or chronic condition resulting from gallbladder stone blockage, disease, injury, or alcoholism Peritonitis An inflammation of the abdominal cavity caused by bacteria

Disorders of the Digestive System (Continued) Phenylketonuria Inherited disease that can lead to mental retardation if untreated Pyloric stenosis A birth defect in which a constricted pyloric sphincter does not allow food to pass easily into the small intestine

Disorders of the Digestive System (Continued) Tay-Sachs A recessive genetic disorder in which fat cells accumulate in the body and cause damage to normal cells Ulcer An open sore on the lining of the digestive tract