Alimentary canal or GI tract

 Extends from the month to anus (29 feet), involved in digestion, absorption, and metabolosm of nutrients

Main organs

Mouth; pharynx; esophagus; stomach; small intestine; large intestine; rectum; anal canal

Accessory organs

teeth and tongue, salivary glands; liver; gallbadder; pancreas; vermigform appendix

Roof

formed by the hard palate

Floor/mouth

formed by hard palate and soft palate and the uvula, a downward projection of sof palate

Leukoplakia

precancerous condition of mouth tissue

Gingivitis

gum inflammation or infection

Periodontitis

inflammation of periodontal membrane

Parotid glands/Submandibular/Sublingual glands

Three pairs of glands that produces saliva