1. 2.07-2.08 Remember the structures of the digestive system

2. DIGESTION
The process of changing complex solid foods into simpler soluble forms which can be absorbed by body cells.
BOLUS – soft, pliable ball – created from chewing and addition of saliva – it slides down esophagus
PERISTALSIS – wavelike motions, moves food along esophagus, stomach and intestines

3. Peristalsis

4. Structures of the digestive system
Also known as:
Alimentary Canal
Digestive Tract
Gastrointestinal Tract
Upper GI
Lower GI
Over 30’ in length from mouth to anus

5. The Digestion Tract

6. Structures of the digestive system
Primary structures
Mouth
Esophagus
Stomach
Small intestines
Large intestines
Accessory structures
Tongue
Teeth
Salivary glands
Pancreas
Liver
Gall bladder
2.07 Remember the structures of the
digestive system

7. Structures of the digestive system
Mouth
(buccal cavity)
Tongue
Teeth
Salivary Glands
Palate
Uvula
The physical breakdown of food begins here first…digestion begins in the mouth

8. Structures of the digestive system
Tongue
Attached to floor of mouth
Made of skeletal muscle attached to four bones
Taste buds on the surface
Sweet
Sour
Bitter
Salty

9. Structures of the digestive system
Teeth
Primary (deciduous)
20 “baby teeth”
Secondary (permanent)
32 “adult teeth”
Did you know???
Canine teeth are also
known as cuspids and
eye teeth.
Teeth and tongue aid in physical / mechanical digestion of food

10. Structures of the digestive system
Salivary glands
Parotid gland
Largest salivary gland
Ptyalin in saliva converts starches to simple sugars causes the initial chemical breakdown.
Submandibular gland
Sublingual gland
2.07 Remember the structures of the
digestive system

11. Structures of the digestive system
Palate – separates the mouth from the nasal cavity
Hard
Soft
Uvula
Flap of skin
hanging in the
back of the throat
2.07 Remember the structures of the
digestive system

12. Structures of the digestive system
Pharynx (throat)
Nasopharynx
Oropharynx
Hypopharynx
2.07 Remember the structures of the
digestive system

13. Structures of the digestive system
Esophagus
Muscular tube, 10” long
Connects the pharynx and stomach

14. Structures of the digestive system
Stomach
Upper left quadrant of the of the abdominal cavity
Fundus
Body
Pylorus
2.07 Remember the structures of the
digestive system

15. Cardiac sphincter - controls passage of food into stomach and keeps it from going back into the throat.
PYLORIC SPHINCTER – valve, regulates the entrance of food into duodenum
RUGAE – mucous coat lining of stomach in folds when the stomach is empty
Stomach has muscular coat that allows it to contract (peristalsis) and push food into the small intestine
2 – 4 hours for stomach to empty

17. Structures of the digestive system
Small intestines – main function is absorption of NUTRIENTS
Duodenum
First segment
12’ long
Jejunum
Second segment
8’ long
Ileum
Third segment
10-12’ long

18. Structures of the digestive system
Large intestines
Approximately 2” in diameter
5’ long
Responsible for elimination of waste and absorption of water

19. Functions of the digestive system
Teeth
Define mastication.
How is the tooth’s shape related to its function?
Incisors
Cuspids
Bicuspids
Molars
2.08 Understand the functions and disorders of the digestive system

20. Accessory Organs of Digestion
PANCREAS
Located behind stomach
Exocrine function – secretes digestive enzymes to break down food.
Also has endocrine function.
Feather shaped organ

21. Functions of the digestive system
Liver
Produce and store glucose in the form of GLYCOGEN
Detoxify alcohol, drugs and other harmful substances
Manufacture blood proteins
Manufactures bile
Store Vitamins A, D and B complex
Connects to gall bladder and small intestine by ducts

22. Functions of the digestive system
Gallbladder
Small muscular green sac that secretes and stores bile
Located in the right upper quadrant of abdominal cavity.
When fatty foods digested, bile released by gallbladder

23. Functions of the digestive system
Large intestine
CHYME – semi-liquid food and gastric juices
Approx 2” in diameter
Also called the colon
CECUM – lower right portion of large intestine
APPENDIX-blind sac attached to cecum, having no known function
RECTUM – last portion of large intestine
ANUS – external opening of the Lg. intestine

24. Disorders of the digestive system
Anorexia
Decreased or poor appetite
Symptom
Anorexia nervosa
Eating disorder characterized by refusal to eat
Psychiatric disorder
Bulimia nervosa (binge eating and purging) is a psychiatric disorder as well VS
Opposite disorder = obesity

25. Obesity is one of the common eating disorders in the United States.
A person is considered obese if their BMI (body mass index is above 30.
How to calculate BMI:
BMI = ( lbs/inches² )
(weight in pounds * 703 )
————————————
height in inches²
BMI
Weight Status
Below 18.5
Underweight
Normal
Overweight
30 & Above
Obese

26. Disorders of the digestive system
Caries
Cavities
How often should you brush and floss?
Can you identify
preventive measures?
2.08 Understand the functions and disorders of the digestive system

27. Disorders of the digestive system
Cholecystitis
Inflammation of the gall bladder
Sx = pain that radiates to right shoulder…frequently after eating fatty foods
How is it treated? - cholecystectomy
Cholelithiasis – gall stones

28. Disorders of the digestive system
Cleft palate
Hard and/or soft palate doesn’t close completely during fetal development
Problems swallowing
Surgery needed to repair
2.08 Understand the functions and disorders of the digestive system

29. Disorders of the digestive system
Cirrhosis
Chronic, progressive disease of liver
Normal tissue replaced by fibrous connective tissue.
75% caused by excessive alcohol consumption (also caused by Tylenol use)

30. Disorders of the digestive system
Constipation
When defecation delayed, feces become dry and hard
Rx – diet with cereals, fruits, vegetables, (roughage), drinking plenty of fluids, exercise, and avoiding tension
2.08 Understand the functions and disorders of the digestive system

31. Disorders of the digestive disorders
Diarrhea
Loose, watery, frequent bowel movements when feces pass along colon too rapidly
Caused by infection, poor diet, nervousness, toxic substances or irritants in food

32. Disorders of the digestive disorders
Gastroenteritis
Inflammation of mucous membrane lining of stomach and intestine
Common cause = virus
Sxs – nausea, vomiting, diarrhea for hours
Complication = dehydration
Prevention…good handwashing

33. Disorders of the digestive system
Gastroesophageal reflux disease (GERD)
Reflux of gastric acid into the espohagus
Sx – burning sensation that often worsens with laying flat…gets better with sitting up or raising head of bed

34. Disorders of the digestive system
Hepatitis
Acute
Chronic
Hepatitis A (contaminated food or water borne), B (blood borne), C (blood borne), D, E
Which hepatitis virus has a vaccine?
2.08 Understand the functions and disorders of the digestive system

35. Disorders of the digestive system
Irritable bowel syndrome
Cause unknown
Sx – abdmonial pain, bloating, diarrhea and constipation (alternating)
Trt – lifestyle and diet changes, medication
2.08 Understand the functions and disorders of the digestive system

36. Disorders of the digestive system
Chron’s Disease
and Ulcerative Colitis
Autoimmune disorders
Type of inflammatory bowel disease
Sxs – abdominal pain, severe diarrhea, malnutrition

37. Disorders of the digestive system
Peptic ulcer - Sore or lesion that forms in the mucosal lining of the stomach
Gastric ulcers in the stomach and duodenal ulcers in the duodenum
Cause – H. pylori (bacteria) is primary cause
Lifestyle factors that contribute: cigarette smoking, alcohol, stress, certain drugs

38. Relevance of nutrition to the digestive system
Vitamins
Fat soluble
Vitamins A, D, E, K
Water soluble
Vitamins C, B
Proteins aid in wound healing
Carbohydrates such as bread and pasta offer quick energy
Electrolytes
Calcium
Chloride
Magnesium
Phosphorus
Potassium
Sodium