1. PowerPoint Lecture Outlines to accompany
Hole’s Human
Anatomy and Physiology
Tenth Edition
Shier w Butler w Lewis
Chapter 17
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. Chapter 17 Digestive System
Functions of Digestive System
ingestion
mechanical digestion
chemical digestion
propulsion
absorption
defecation

3. Major Organs

4. Alimentary Canal Wall

5. Movements of the Tube
mixing movements
peristalsis

6. Innervation of the Tube
submucosal plexus – controls secretions
myenteric plexus – controls gastrointestinal motility
parasympathetic impulses – increase activities of digestive system
sympathetic impulses – inhibit certain digestive actions

7. Palate
roof of oral cavity

8. Salivary Glands

9. Secretions of Salivary Glands
Parotid glands
clear
water, serous fluid
rich in amylase
Sublingual glands
primarily mucus
most viscous
Submandibular glands
primarily serous fluid
some mucus

10. Swallowing Mechanism soft palate and uvula raise
hyoid bone and larynx elevate
epiglottis closes off top of trachea
longitudinal muscles of pharynx contract
inferior constrictor muscles relax and esophagus opens
peristaltic waves push food through pharynx

11. Swallowing Mechanism

12. Esophagus

13. Stomach

14. Lining of Stomach

15. Gastric Secretions pepsinogen from chief cells inactive form of pepsin
mucus
from goblet cells and mucous glands
protective to stomach wall
pepsin
from pepsinogen in presence of HCl
protein splitting enzyme
intrinsic factor
from parietal cells
required for vitamin B12 absorption
hydrochloric acid
from parietal cells
needed to convert pepsinogen to pepsin

16. Phases of Gastric Secretion
Cephalic phase
triggered by smell, taste, sight, or thought of food
parasympathetic impulses trigger gastric juice secretion
Gastric phase
triggered by presence of food in stomach
gastrin released
gastric juice secreted
Intestinal phase
triggered by movement of food into small intestine
intestinal cells release intestinal gastrin
secretion of gastric juice

17. Regulation of Gastric Secretions

18. Gastric Absorption some water certain salts
certain lipid-soluble drugs
alcohol

19. Mixing and Emptying Actions

20. Enterogastric Reflex
regulates the rate at which chyme leaves the stomach

21. Pancreas

22. Pancreatic Juice
pancreatic amylase – splits glycogen into disaccharides
pancreatic lipase – breaks down triglycerides
trypsin, chymotrypsin, and carboxypeptidase – digest proteins
nucleases – digest nucleic acids
bicarbonate ions – make pancreatic juice alkaline

23. Regulation of Pancreatic Secretions
acidic chyme stimulates release of secretin
secretin stimulate release of pancreatic juice

24. Liver

25. Hepatic Lobule

26. The Paths of Blood and Bile in Hepatic Lobule

27. Liver Functions produces glycogen from glucose
breaks down glycogen into glucose
converts noncarbohydrates to glucose
oxidizes fatty acids
synthesizes lipoproteins, phospholipids, and cholesterol
converts carbohydrates and proteins into fats
deaminates amino acids
forms urea
synthesizes plasma proteins
converts some amino acids to other amino acids
stores glycogen, vitamins A,D, B12, iron, and blood
phagocytosis of worn out RBCs and foreign substances
removes toxins from blood
produces and secretes

28. Composition of Bile water bile salts bile pigments cholesterol
emulsification of fats
absorption of fatty acids, cholesterol, and fat-soluble vitamins
bile pigments
cholesterol
electrolytes

29. Gallbladder

30. Regulation of Bile Release
fatty chyme entering duodenum stimulate gallbladder to release bile

31. Three Parts of Small Intestine

32. Mesentery
suspends portions of the small intestine from the posterior abdominal wall

33. Intestinal Villus

34. Intestinal Epithelium

35. Wall of Small Intestine

36. Secretions of Small Intestine
peptidase – breaks down peptides into amino acids
sucrase, maltase, lactase – break down disaccharides into monosaccharides
lipase – breaks down fats into fatty acids and glycerol
enterokinase – converts trypsinogen to trypsin
somatostatin – hormone that inhibits acid secretion by stomach
cholecystokinin – hormone that inhibits gastric glands, stimulates pancreas to release enzymes in pancreatic juice, stimulates gallbladder to release bile
secretin – stimulates pancreas to release bicarbonate ions in pancreatic juice

37. Regulation of Small Intestinal Secretions
mucus secretion stimulated by presence of chyme in small intestine
distension of intestinal wall activates nerve plexuses in wall of small intestine
parasympathetics trigger release of intestinal enzymes

38. Absorption in the Small Intestine
monosaccharides and amino acids
through facilitated diffusion and active transport
absorbed into blood
electrolytes and water
through diffusion, osmosis, and active transport
absorbed into blood

39. Absorption in the Small Intestine
fatty acids and glycerol
several steps
absorbed into lymph and blood

40. Movements of the Small Intestine
mixing movements
peristalsis – pushing movements
segmentation – ringlike contractions
overdistended wall triggers peristaltic rush resulting in diarrhea

41. Large Intestine

42. Large Intestinal Wall

43. Functions of Large Intestine
little or no digestive function
absorbs water and electrolytes
secretes mucus
houses intestinal flora
forms feces
carries out defecation

44. Movements of Large Intestine
slower and less frequent than those of small intestine
mixing movements
peristalsis
mass movements usually follow meals

45. Feces water electrolytes mucus bacteria
bile pigments altered by bacteria provide color
smell produced by bacterial compounds

46. Clinical Application Hepatitis inflammation of the liver
most commonly caused by viral infection
can be caused by reactions to drug, alcoholism or autoimmunity
Signs and Symptoms
headache
low fever
fatigue
vomiting
rash
foamy urine
pale feces
jaundice
pain
Hepatitis A – not washing hands or eating raw shellfish
Hepatitis B – chronic; serum
Hepatitis C – serum
Hepatitis D – very severe; only produces symptoms if infected with B; serum
Hepatitis E, F, G – more rare