1. The Digestive System and Body Metabolism14
The Digestive System and Body Metabolism

2. CH 14 THE DIGESTIVE SYSTEM
I. Overview Of The Digestive System
*Function:
B. Major Processes
Ingestion, Digestion, Absorption, and
Defecation
C. Organs
*Alimentary Canal define & list organs
*Accessory Digestive Organs define & list organs
Sphincters

3. Mouth (oral cavity)
Parotid gland
Tongue
Sublingual gland
Salivary glands
Submandibular
gland
Pharynx
Esophagus
Stomach
Pancreas
(Spleen)
Liver
Gallbladder
colon
Transverse
Duodenum
Descending
colon
Small intestine
Jejunum
lleum
Ascending
colon
Large intestine
Cecum
Sigmoid colon
Rectum
Appendix
Anus
Anal canal
Figure 14.1

4. II. Organs of the Digestive System A. Alimentary Canal Organs. 1
II. Organs of the Digestive System A. Alimentary Canal Organs 1. Mouth (Oral Cavity)
Uvula
a. Anatomy
*Oral cavity proper define
*Uvula define
- Function
*Tongue define
Teeth
Tonsils
Tonsils

5. b. Mouth Physiology *Masticated (mastication): define
Mixing with saliva
Swallowing:
Function of Uvula, Tongue, Pharynx
iii) Taste
iv) Chemical Digestion:
Enzyme:
Amylase + Starch Glucose + Glucose …

6. 2. Pharynx a. Anatomy: Review
Nasopharynx
Hard
palate
Soft palate
Oral
cavity
Uvula
Lips (labia)
Palatine tonsil
Vestibule
Lingual tonsil
Oropharynx
Lingual
frenulum
Epiglottis
Tongue
Laryngopharynx
Hyoid bone
Esophagus
Trachea
(a)

7. b. Pharynx Physiology 1. *Substances that move through the Pharynx:
2. Subdivides into: Larynx and Esophagus
3. How keep food out of Lungs–
*Epiglottis of the Larynx– see Respiratory system
Larynx
Esophagus

8. 3. Esophagus
Anatomy
*Length:
b. *Location:
c.* Function:
Esophagus

9. 4. Stomach a. Anatomy *Location: *Shape *Amount of food it can hold:
Cardioesophageal Sphincter
*Location:
*Shape
*Amount of food it can hold:
*Rugae
Sphincters
Cardioesophageal
Pyloric
Smooth muscle in Walls– 3 layers
Inner layer: type of tissue =
Mucus
Microscopic- Gastric Glands
Secrete:
Pyloric Sphincter
Rugae
Gastric Glands

10. Fundus Body Rugae of mucosa Pyloric (b) Pyloric sphincter antrum
Figure 14.4b

11. b. Stomach Physiology/Functions
Temporary storage
Physical Breakdown
*Intrinsic Factor function
iv) Digestion of Proteins
Gastric Juice contains:
- Hydrochloric Acid (HCl):
Pepsinogen:
Pepsin: activated form of enzyme Pepsinogen; activated by HCl
Chief Cells
Parietal
Cells
Pepsinogen
Gastric Glands
Pepsin
HCl

12. Pepsin …
Pepsin digests Proteins into its subunits, Amino Acids
Pepsin + Proteins Amino Acids + A.A. …

13. Smooth Muscle: two layer *Major Parts: list (3) Inner folds Function
5. Small Intestine
Gross View
a. Anatomy
i) Gross
(1) *Shape & Length:
Smooth Muscle: two layer
*Major Parts: list
(3) Inner folds
Function
ii) Microscopic Anatomy
(1) Tissue of Lining:
(2) *Villi: describe
Blood vessels
*Lacteal: define
Muscle Layers
Villi
Circular Folds
Microscopic view of Villi
Lacteal

14. Microvilli (brush border) (c) Absorptive cells Absorptive cells
Lacteal
Villus
Blood
capillaries
Lymphoid
tissue
Intestinal
crypt
Muscularis
mucosae
Venule
Lymphatic vessel
(c) Absorptive
cells
Submucosa
(b) Villi
Figure 14.7b

15. ii) Microscopic Anatomy …
*Microvilli define
Function
b. Special Functions of the Duodenum
i) Location
ii) Two Adjacent Accessory Organ:
iii) Substances received
Pancreas:
Pancreatic Duct
Liver:
Bile Duct
Microvilli on a cell
Liver & Bile Duct
Duodenum
Pancreas & Pancreatic Duct

16. END

17. Cardioesophageal sphincter Fundus Esophagus Muscularis externa Serosa
• Longitudinal layer
• Circular layer
Body
• Oblique layer
Lesser
curvature
Rugae of
mucosa
Pylorus
Greater
curvature
Duodenum
Pyloric
Sphincter
(valve)
Pyloric
antrum
(a)
Figure 14.4a