1. DIGESTIVE SYSTEM Performs 3 tasks:
Mechanical Digestion – No chemical reactions
2. Chemical Digestion – Chemical reactions
3. Absorbtion – Absorbing nutrients into blood
system

2. Pg. 650
Fig
Accessory
Organs
Alimentary
Canal

3. Pg. 8
Packet

4. Fig. 15.02 Pg 651 8 meters (24 feet) from Mouth to Anus
186 square meters
total surface area

5. Movements of the Tube
1.The motor functions of the alimentary canal are of two types— mixing movements and propelling movements.
2. Mixing movements occur when smooth muscles contract rhythmically in small sections of the tube.
3. Propelling movements include a wavelike motion called peristalsis, which is caused by contraction behind a mass of food as relaxation allows the mass to enter the next segment of the tube.

6. Pg. 653
Mixing Movement
Propelling Movement
Peristalsis

7. Fig
Pg. 655

8. Fig
Pg. 653

9. Pg. 655

11. Pg. 656

12. Fig
Pg. 657

14. Pepsi 2.49
Gatorade 2.4
Vitamin Water 3-4
Grapefruit Juice 2.8
Red Bull 3.5
Milk 6.8
Coke 2.53
Snapple Tea 3.2
Orange Juice 3-4
V9Splash Berry 3.1
SoBe Tropical 2.5

15. Fig. 15.10 SALIVARY GLANDS Pg. 658 1. Amylase 3. 2. Amylase & Mucus
Serous Cells 1.
Amylase 3.
Mucous Cells
Serous &
Mucous Cells 2.
Amylase &
Mucus

16. Swallowing Mechanism
Swallowing reflexes can be divided into three stages.
a. Food is mixed with saliva and voluntarily forced into the pharynx with the tongue.
b. Sensory receptors in the pharynx sense food, which triggers swallowing reflexes.
c. In the third stage of swallowing, peristalsis transports the food in the esophagus to the stomach.

17. Structure of the Wall
1.The wall of the alimentary canal consists of the same four layers throughout its length, with only slight variations according to the functions of specific sections of the canal.

18. 4 Layers of Alimentary Canal
Pg. 652 1. 2. 3. 4.

19. The inner layer is the mucosa, which is lined with epithelium attached to connective tissue; it protects tissues of the canal and carries on secretion and absorption.
The next layer is the submucosa, which is made up of loose connective tissue housing blood and lymph vessels and nerves; it nourishes the surrounding layers of the canal.
The muscular layer consists of inner circular fibers and outer longitudinal fibers that propel food through the canal.
d. The outer layer, or serosa, is composed of visceral peritoneum that protects underlying tissues and secretes serous fluid to keep the canal from sticking to other tissues in the abdominal cavity.

22. STOMACH
Pg. 662
Body Region

23. Gastric Secretions
Gastric glands within the mucosa of the stomach open as gastric pits.
Gastric glands generally contain three types of secretory cells.
a. Mucous cells produce mucus that protects the stomach
lining.
b. Chief cells secrete pepsin (to digest protein) as inactive
pepsinogen, which is activated when it comes in contact
with hydrochloric acid.
c. Parietal cells secrete hydrochloric acid.
d. Other components of gastric juice include intrinsic factor, required for vitamin B12 absorption from the small intestine.

24. Pg. 664 a.
b,. c.

25. Pg. 665

26. Gastric Absorption
1. The stomach absorbs only small quantities of water and certain salts, alcohol, and some lipid-soluble drugs.

27. Mixing and Emptying Actions
Following a meal, mixing actions of the stomach turn the food into chyme and pass it toward the pyloric region using peristaltic waves.
The rate at which the stomach empties depends on the fluidity of the chyme and the type of food.
As chyme fills the duodenum, stretching of its wall triggers the enterogastric reflex, which inhibits peristalsis and slows the rate at which chyme enters the small intestine.

28. Regulation of Gastric Secretions
SECRETIONS INCREASED: Gastric secretions are enhanced by parasympathetic impulses from vagus nerve and the hormone gastrin, which is released from gastric glands.
Gastrin stimulates the release of gastric juices and the
release of histamine, which stimulates the release of HCL.
SECRETIONS DECREASED: As more food enters the small intestine, secretion of gastric juice from the stomach wall is inhibited. Sympathetic impulses aid in inhibition
a. Presence of fats and proteins in the upper small intestine causes the release of the hormone cholecystokinin (CCK) from the intestinal wall, which also decreases gastric mobility.

29. PG 665

31. PANCREAS
Fig
Pg. 668

32. Pg. 669

33. Regulation of Pancreatic Secretion
The nervous and endocrine systems regulate release of pancreatic juice.
The hormone Secretin from the duodenum wall stimulates the release of pancreatic juice with a high bicarbonate ion concentration. Neutralizes acidic chyme.
The hormone Cholecystokinin (CCK) also from the duodenum wall stimulates the release of pancreatic juice with a high concentration of digestive enzymes.

34. Pg. 669

35. PANCREAS Pancreatic Juice
Pancreatic juice contains enzymes that digest carbohydrates, fats, proteins, and nucleic acids.
Pancreatic enzymes include:
pancreatic amylase (Carbs),
pancreatic lipase (Lipids),
trypsin, chymotrypsin, carboxypeptidase (Proteins)
two nucleases (Nucleic Acids).
3. Protein-digesting enzymes are released in an inactive form and are activated upon reaching the small intestine.

36. Fig
Pg. 668

37. Fig a
LIVER
Pg. 671

38. Liver Structure
The liver is divided into right and left lobes, and is enclosed by a fibrous capsule.
Each lobe is separated into hepatic lobules consisting of hepatic cells radiating from a central vein. These are the livers functional units.
Hepatic sinusoids (Vascular channels) separate groups of hepatic cells.
Hepatic
Lobule
Bile Duct
Pg. 671
Sinusoids
Central Vein

39. 4. Blood from the hepatic portal vein carries blood rich in nutrients to the liver.
5. Kupffer cells carry on phagocytosis in the liver.
6. Secretions from hepatic cells are collected in bile canals that converge to
become hepatic ducts and finally form the common hepatic duct.
Hepatic Cells
Bile Duct
Kupffer Cell
Branch of
Hepatic portal
vein
Pg. 672

40. Table
Pg. 673

41. Liver Functions
1.The liver's main role in digestion
is to secrete bile.

42. Composition of Bile
Bile is a yellowish-green liquid that hepatic cells secrete; it includes water, bile salts, bile pigments, cholesterol, and electrolytes.
Bile pigments are breakdown products from red blood cells.
3. Only the bile salts have a digestive function.

43. Functions of Bile Salts
Bile salts emulsify fats into smaller droplets and aid in the absorption of fatty acids, cholesterol, certain vitamins.

44. If Bile is used right away goes from Hepatic (Bile) Duct, down the common
bile duct into the small intestine.
If Bile is not used right away it goes from Hepatic (Bile) Duct, into Cystic
Duct and then stored in the Gallbladder
Pg. 671

45. Pg. 668

46. Fig
Regulation of
Liver and
Gallbladder
secretion
Pg. 675

49. SMALL INTESTINE

50. SMALL INTESTINE
Fig
Pg. 676

51. Fig
Pg. 677

52. Structure of the Small Intestinal Wall
The inner wall of the small intestine is lined with finger-like intestinal villi, which greatly increase the surface area available for absorption and aids in mixing actions.
Each villus contains a core of connective tissue housing blood capillaries and a lymphatic capillary called a lacteal.
3. Between the bases of adjacent villi are tubular intestinal glands.

53. Pg. 652

54. Embedded in the epithelial cells of the villi are digestive enzymes
that break food molecules down one last time before absorbtion:
They include:
SUCRASE, MALTASE AND LACTASE –
Breakdown disaccharides to monosaccharide
PEPTIDASES
Breakdown peptides to amino acids
INTESTINAL LIPASE
Breakdown fats into fatty acids and glycerol

55. Fig. 15.24 Pg. 678 Lack digestive enzymes
Abundant in digestive enzymes
SUCRASE, MALTASE, LACTASE
PEPTIDASES
INTESTINAL LIPASE
Pg. 678
Lack digestive enzymes

57. Fig. 15.25 Pg. 678 Epithelial cells are continually replaced
New cells made in intestinal glands,
migrate onto villus surface.
When they reach the tip of villus they
shed.
Epithelial cells of small intestine
replaced every 3-6 days.

58. Fig. 15.24 Pg. 678 Lack digestive enzymes
Abundant in digestive enzymes
SUCRASE, MALTASE, LACTASE
PEPTIDASES
INTESTINAL LIPASE
Pg. 678
Lack digestive enzymes

59. Pg.682

60. PG 681
Fig

61. Lipoproteins – Made up of phospholipid, protein,
cholesterol and triglycerides.
Types of Lipoproteins
Chylomicrons – transport dietary fat to muscle and
adipose cells.
2. VLDL – transport triglycerides to adipose cells
3. LDL – transports cholesterol to tissue cells
4. HDL – transports cholesterol from tissue cells to
liver where it becomes part of the bile salts or is
eliminated from intestine.

62. Pg. 675

63. Table
Pg. 680

64. Structure of the Large Intestinal Wall
The large intestinal wall has the same four layers found in other areas of the alimentary canal, but lacks many of the features of the small intestinal mucosa such as villi.
2. Fibers of longitudinal muscle are arranged in teniae coli that extend the entire length of the colon, creating a series of pouches (haustra).

65. Pg. 683 2. Transverse Colon 1. Ascending Colon 3. Decending Colon
4. Rectum
5. Anus

66. Fig
Pg. 684

67. Functions of the Large Intestine
The large intestine does not digest or absorb nutrients, but it does secrete mucus.
The large intestine absorbs electrolytes and water.
3. The large intestine contains important bacteria which break down cellulose for energy and in return synthesize vitamins k, B12, thiamine and riboflavin.

68. Movements of the Large Intestine
The movements of the large intestine are similar to those of the small intestine.
Peristaltic waves happen only two or three times during the day.
3. Defecation is stimulated by a defecation reflex that forces feces into the rectum where they can be expelled.

69. Feces
Feces are composed of undigested material, water, electrolytes, mucus, epithelial cells of the small intestine and bacteria.
2. Both the color of feces and its odor is due to the action of bacteria.

70. Pg. 684

71. Secretions of the Small Intestine
Cells that secrete mucus in the small intestine include goblet cells, which are abundant throughout the mucosa, and mucus-secreting glands located in the submucosa of the duodenum.
Intestinal glands at the bases of the villi secrete large amounts of watery fluid that carry digestive products into the villi.
3. Epithelial cells of the mucosa have embedded digestive enzymes on their microvilli, including peptidases, sucrase, maltase, and lactase, and intestinal lipase.

72. 4. Fatty acids are absorbed and transported
4. Fatty acids are absorbed and transported differently than the other nutrients.
a. Fatty acid molecules dissolve into the cell membranes of the villi.
b. The endoplasmic reticula of the cells reconstruct the lipids.
c. These lipids collect in clusters that become encased in protein (chylomicrons).
d. Chylomicrons are carried away in lymphatic lacteals until they eventually join the bloodstream.
5. The intestinal villi also absorb water (by osmosis) and electrolytes (by active transport).

75. Liver Functions
The liver carries on many diverse functions for the body.
The liver is responsible for many metabolic activities, such as the metabolism of carbohydrates, lipids, and proteins.
The liver also stores glycogen, vitamins A, D, and B12, iron, and blood.
The liver filters the blood, removing damaged red blood cells and foreign substances, and removes toxins.
5. The liver's role in digestion is to secrete bile.