ORAL CAVITY AND PHARYNX

The oral cavity is the mouth.
It contains: the tongue, teeth, salivary glands, lips, oral pharynx, palate, cheeks, and gums.

The salivary glands produce saliva. Saliva lubricates the mouth, helps with swallowing (diglution), and protects the teeth.

The tongue rolls food into boli and pushes them to the back of the oral cavity for diglution.

A bolus (plural: boli) is a soft, round mass of chewed food ready for diglution.

THE HARD PALATE

• is located in the front of the roof of the mouth.
• It helps with articulation and speech.
• It also divides the nasal passages.

THE SOFT PALATE

• is located in the back of the roof of the mouth.
• It also aids with articulation and speech.
• It closes off the nasal passages during diglution.

The mechanical digestion that occurs in the oral cavity is diglution. The chemical digestion begins when the saliva's enzymes (amylase) breaks down the carbohydrates and the salivary lipase breaks down the fats.

To prevent food from entering the airway, the epiglottis covers the larynx during diglution. The epiglottis is a lid-like structure.

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ENZYMES OF THE ORAL CAVITY

• The salivary glands secrete:
• Lysozyme (an antibacterial enzyme)
• Ptyalin (converts starch to simple soluble sugar)
• Amylase (converts carbs to soluble sugar)
• Betaine (maintains cell fluid balance)

ENZYMES CONTINUED

• Bromelain (is an anti-inflammatory agent
• and tenderizes meat)
• Lipase (breaks down fats)

FOOD

• Skittles (carb) - amylase immediately breaks it down
• Steak (protein) - bromelain tenderizes
• Celery - no enzymes break it down, is an insoluble fiber
• Bread (starch) - ptyalin breaks down into soluble sugars
• Butter (fat) - lipase breaks it down

All these foods get rolled into boli and continued through the digestive system after any enzymes break them down.