Anatomy of Mouth, Throat, Nose, and Paranasal Sinuses

Mouth

• Tongue is a mass of muscle attached to the hyoid bone and styloid process of the temporal bone, assisting with moving food, swallowing, and speaking
• Frenulum is a fold of tissue connecting the floor of the mouth
• Gums (gingiva) are covered by mucous membrane and normally hold 32 permanent teeth in the adult
• Crown is the top, visible, white enameled part of each tooth
• Root is the portion of the tooth that is embedded in the gums
• Neck is the region of the tooth that connects the crown and root
• Papillae are small bumps covering the dorsal surface of the tongue
• Taste buds are scattered over the tongue's surface, carrying sensory impulses to the brain

Salivary Glands

• There are three pairs of salivary glands that secrete saliva into the mouth
• Saliva is a watery, serous fluid containing salts, mucus, and salivary amylase
• Saliva helps break down food and lubricates it
• Amylase digests carbohydrates
• Parotid glands are located below and in front of the ears, emptying through Stensen ducts
• Submandibular glands are located in the lower jaw
• Wharton ducts are openings under the tongue on either side of the frenulum
• Sublingual glands are located under the tongue, opening through several ducts on the floor of the mouth

Throat

• Throat (pharynx) is a muscular passage for food and air, located behind the mouth and nose
• Nasopharynx is the upper part of the throat
• Oropharynx lies below the nasopharynx
• Laryngopharynx lies below the oropharynx
• The soft palate, anterior and posterior pillars, and uvula connect behind the tongue to form arches
• Palatine tonsils are masses of lymphoid tissue located on both sides of the oropharynx at the end of the soft palate between the anterior and posterior pillars
• Lingual tonsils are located at the base of the tongue
• Pharyngeal tonsils or adenoids are found high in the nasopharynx

Nose

• Consists of an external portion covered with skin and an internal nasal cavity
• External nose consists of a bridge (upper portion), tip, and two oval openings called nares
• Nasal cavity is located between the roof of the mouth and the cranium
• Nasal septum separates the cavity into two halves
• Cranial nerves V (trigeminal), VII (facial), IX (glossopharyngeal), and XII (hypoglossal) assist with mouth and throat functions
• Cranial nerve I (olfactory) receptors are located in the nose and relate to the sense of smell

Mouth and Throat Functions

• Mouth and throat comprise the first part of the digestive system and are responsible for receiving food, tasting, preparing food for digestion, and aiding in speech
• Nose and paranasal sinuses constitute the first part of the respiratory system and are responsible for receiving, filtering, warming, and moistening air to be transported to the lungs