Function: interface between body and environment, digestion:
food is broken down physically and chemically so that the degraded products can be
absorbed into the body.
- Barrier function: The mucosa serves as a barrier to the noxious substances,
antigens, and pathogenic organisms.
- Immunologic function: Lymphatic tissue in the
mucosa serves as a first line of defense of the body by the immune system.
- Secretory function: The lining of the alimentary canal secretes, at specific sites,
digestive enzymes, hydrochloric acid, mucin, and antibodies.
- Absorptive function: The epithelium of
the mucosa absorbs metabolic substrates, i.e., the breakdown products of digestion,
vitamins, water, electrolytes, recyclable materials such as bile components and
cholesterol and other substances.
6. Salivary gland
ESOPHAGUS and GASTROINTESTINAL TRACT
9. Small intestine
10. Large intestine
LIVER, GALLBLADDER, and PANCREAS