NASAL AND ORAL CAVITIES(PRACTICAL)

Nasal and Oral Cavities

Definition of Terms

Nasal cavity

The nasal cavity (or nasal fossa) is a large air filled space on top of and behind the nose in the middle of the face. Each cavity is the extension of one of the two nostrils. It is lined with a mucous membrane that helps keep your nose moist by making mucus so you won’t get nosebleeds from a dry nose.

Tongue

The tongue is a muscular organ in the mouth that is filled with moist pink tissue known as mucosa. It has tiny bumps known as papilla that gives it its characteristic rough texture. The papillae are made up of thousands of taste buds. These are nerve like cells that links the nerves that goes into the brain.

Nasopharynx

The nasopharynx is defined as the upper part of the throat behind the nose. It is a part of the pharynx, which is composed of three sections: the nasopharynx, oropharynx and the hypopharynx. It is 2 to 3 cm wide and 3 to 4 cm long and is located behind the nasal fossa inside the occipital bone.

Oropharynx

This is the part of the throat at the back of the mouth. It includes the back third of the tongue, the soft palate, the side and back walls of the throat, and the tonsils. The oropharynx lies behind the oral cavity, and extends from the uvula to the level of the hyoid bone. It opens anteriorly, through the isthmus faucium.

Hypopharynx

The inferior portion of the pharynx, between the epiglottis and the larynx. It is of the same height with the epiglottis and is a vital dividing point in separating solids and fluids from air entering the region. It is the portion of the pharynx below the upper edge of the epiglottis, opening into the larynx and esophagus.