1. Introduction to Medical Careers
Digestive System
Chapter 16

2. 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

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

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

5. 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

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

7. 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

8. 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

9. 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

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

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

15. 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

16. Table 16-1 Digestive System

17. 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

18. 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

19. 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

20. Figure Endoscopy

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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

27. 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

28. 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