Anatomy of the Mouth

Anatomy of the Mouth

The mouth is the first organ of the digestive system, playing a crucial role in chewing, swallowing, speech, and taste perception. The structure of the mouth includes:

1. Vestibule of the mouth:

• Boundaries: Anterior to the dental arches, external to the upper and lower lips, connected to the outside through the oral fissure, internal to the mucocutaneous fold from the lips and cheeks to the gums.

• Function: Space where food is held before being transferred to the oral cavity proper.

2. Upper and lower lips:

• Structure: Consists of skin, mucous membrane, orbicularis oris muscle, blood vessels, labial nerves, fibrous adipose tissue, and minor salivary glands that drain into the vestibule of the mouth.

• Function: Encloses the oral fissure, helps open and close the mouth, participates in speech, and expresses emotions.

3. Philtrum:

• Structure: Vertical groove in the skin of the lip.

4. Labial frenulum:

• Structure: Fold of mucous membrane connecting the gum and lip.

5. Cheeks:

• Structure: Composed of skin, muscles (buccinator muscle, masseter muscle, zygomaticus major muscle, risorius muscle, platysma muscle), buccal fat pad, and mucous membrane.

• Function: Forms the sides of the mouth, assists in chewing, and contains the opening of the parotid duct above the second molar tooth.

6. Oral cavity proper:

• Boundaries: Anterior and lateral are the dental arches, teeth, and gums. It communicates with the pharynx through the oropharynx.

• Roof: Hard palate and soft palate.

• Floor: Lingual mucous membrane and inner surface of the mandible.

• Function: The site of chewing and grinding food and preparing it for swallowing.

7. Lingual frenulum:

• Structure: Fold of mucous membrane connecting the floor of the mouth and the underside of the tongue.

8. Two sublingual caruncles:

• Structure: Located on either side of the lingual frenulum on the floor of the oral cavity proper, where the submandibular ducts open.

9. Gums:

• Structure: Layer of soft tissue covering the dental arches, composed of fibrous tissue and covered by stratified squamous epithelium.

• Function: Encloses and protects teeth, provides a stable platform for chewing, and contributes to speech.

• Two parts: The free gingiva surrounding the neck of the tooth and the attached gingiva firmly attached to the alveolar bone of the mandible and maxilla.

10. Gingival papilla:

• Structure: Elevated portion of the mucous membrane on the labial surface of the gingiva.

11. Palate:

• Hard palate: Formed by the palatine process of the maxilla and horizontal plate of the palatine bone.

• Soft palate: Movable soft tissue attached to the posterior margin of the hard palate, extending downwards and posteriorly.

• Uvula: The terminal projection of the soft palate, extending downwards.

• Two palatoglossal arches, palatopharyngeal arches: Delimiting the tonsillar fossa containing the palatine tonsils.

• Function: Assists in swallowing, speech, and prevents food from regurgitating into the nasal cavity.

12. Salivary glands:

• Classification: Major salivary glands (parotid, submandibular, sublingual) and minor salivary glands (labial, buccal, palatine, lingual).

• Function: Secretes saliva, which moistens food, digests starch, and protects the oral cavity from bacteria.

13. Parotid gland:

• Characteristics: Largest salivary gland, weighing approximately 25g, located below the external auditory canal, between the ascending ramus of the mandible and the sternocleidomastoid muscle.

• Includes: Superficial part, posterior part, parotid duct, and accessory parotid gland.

Note: This is a brief summary of the anatomy of the mouth. To understand the structure and function of the mouth in detail, consult reliable medical sources for further information.