The next part of the mouth is the mouth cavity. It houses the teeth, tongue, subtongue or salivary glands. The mouth is always moist as it is covered by the mucous membrane oral mucosa. The floor of the mouth is made up of the mylohyoid muscle. At the back of the oral cavity is the soft palate which prevents food from entering the nostrils. Here the food stays for 5-30 seconds.
The tongue has 2000-8000 taste buds. There are five types of taste buds. Sweetness, saltiness, sourness or acidity, savory or umami and bitterness. Taste buds are replaced by new formations every 5-10 days. Each taste bud contains 50-100 taste receptor cells. Taste receptor cells are located in the form of papillae.
Oral function
(i) Tongue helps in tasting and swallowing food.
(ii) Teeth participate in cutting, tearing and grinding of food.
(iii) Salivary glands secrete saliva.
(iv) Lysozyme destroys bacteria.