Final answer:
The oral cavity, or buccal cavity, is the mouth that starts the digestion process by breaking down food through mastication and enzymatic action of saliva. It includes several structures such as cheeks, lips, gums, teeth, oral vestibule, and muscles like the buccinator and orbicularis oris.
Step-by-step explanation:
The oral cavity, also known as the buccal cavity, refers to the mouth which includes the cheeks, tongue, and palate. This cavity serves as the beginning of the digestive system, where both physical and chemical digestion commence. The oral cavity has several components: the oral vestibule which is the area bounded externally by the cheeks and lips and internally by the gums and teeth, and the main open area known as the oral cavity proper. The food we consume is broken down into smaller particles by mastication, the action of the teeth, which is the first step in preparing the food for digestion.
Inside the mouth, the lips cover the orbicularis oris muscle and are attached to the gums by the labial frenulum. The cheeks are composed of skin on the outside and a mucous membrane on the inside, which involves connective tissue and the buccinator muscles. These muscular structures are important in keeping the food within the mouth during chewing and play a crucial role in speaking. The tongue, salivary glands, and teeth are also key accessory organs associated with the mouth.
The produced saliva contains enzymes like salivary amylase, which begins the digestion of starches into maltose, and lingual lipase, which starts the breakdown of fats. After being chewed and mixed with saliva, the food forms a mass called the bolus, which is then moved to the pharynx by the tongue, initiating the act of swallowing.