The oral cavity, commonly known as the mouth, is the initial gateway for essential bodily processes. This complex region facilitates functions from communication to digestion. Understanding its parts provides insight into its operational efficiency. This article explores the structure and roles of the lower part of the mouth.
The Oral Floor
The “bottom of your mouth” is scientifically known as the oral floor. This region encompasses soft tissues beneath the tongue and above the hyoid bone, a U-shaped bone in the neck. It is a dynamic and flexible space, primarily lined with a thin, non-keratinized mucous membrane, giving it a smooth and moist appearance.
Its specialized lining allows for flexibility and contributes to physiological processes. Visible blood vessels and salivary gland duct openings are also present. Its soft, pliable nature provides foundational support for the tongue, enabling its extensive range of motion and complex movements.
Anatomical Components
The oral floor comprises several distinct anatomical structures. A group of muscles, collectively known as the suprahyoid muscles, forms its muscular diaphragm. The mylohyoid muscles create the primary muscular sling, providing a strong base for the tongue and elevating the hyoid bone during swallowing. Positioned above the mylohyoid, the geniohyoid muscles contribute to this support and help depress the mandible, or lower jaw.
The digastric muscles, located below the mylohyoid, assist in opening the mouth and moving the hyoid bone. These muscles collectively enable precise movements for speech and initial food processing, providing both support and mobility within the oral cavity.
Two types of salivary glands are associated with the oral floor. The sublingual glands, the smallest major salivary glands, are situated beneath the mucous membrane, anterior to the submandibular glands. They release saliva through small ducts along the sublingual fold. The ducts of the submandibular glands (Wharton’s ducts) also open onto the oral floor at small papillae on either side of the lingual frenulum.
The lingual frenulum is a prominent fold of mucous membrane extending from the floor of the mouth to the underside of the tongue, anchoring it and limiting its posterior movement. A rich network of blood vessels, including branches of the lingual artery and vein, supplies the oral floor with oxygen and nutrients. Nerves like the lingual nerve provide sensation, and the hypoglossal nerve innervates some oral floor muscles.
Essential Functions
The oral floor plays a multifaceted role in daily bodily functions. Its muscular components, particularly the mylohyoid and geniohyoid muscles, are instrumental in speech articulation. These muscles assist in positioning the tongue and shaping the oral cavity, allowing for the precise sounds required for clear communication.
During swallowing, or deglutition, the oral floor muscles elevate the hyoid bone and the tongue, propelling food from the mouth into the pharynx. This coordinated action prevents food from entering the airway and ensures it moves efficiently towards the esophagus. The oral floor’s support and flexibility are also crucial during chewing, or mastication, as it helps to stabilize the lower jaw and position food between the teeth. The muscles assist in manipulating the food bolus, preparing it for swallowing.
The salivary glands located within or opening onto the oral floor are responsible for producing and distributing saliva. Saliva lubricates the mouth, aids in the initial breakdown of food through enzymes, and helps maintain oral hygiene. The thin mucous membrane and extensive blood vessel network of the oral floor make it an effective site for sublingual medication absorption. Certain medications, like those for angina, can rapidly enter the bloodstream when placed under the tongue, bypassing the digestive system and liver for quicker effects.