What is the Buccal Cavity?

The buccal cavity is more commonly known as the mouth, and it is the beginning of the digestive system for humans and animals alike. It starts with the lips and ends with the throat, covering the oral cavity, the tongue, and the jaw in between. Digestion is its primary function, but it also has an important role in communication. The development of speech, including words and sounds, happens here, and expressions made with the mouth are often an important part of non-verbal social cues and communications, too.

Most medical experts talk about the mouth in terms of its two main sections, known as the vestibule and the buccal cavity proper. The vestibule is the gap between the teeth and cheeks, while the cavity proper is portion of the mouth between the teeth, which includes the tongue and throat, is roofed by the hard and soft palates, and is floored by the tongue. Both sections have important roles to play. The vestibule receives the secretion of saliva and transfers this to the main cavity, which is where digestion first gets started. When the two parts work together a person is able to chew, break down, and swallow food and drink.

At least in humans, the buccal cavity begins with the lips. The lips are made up of upper and lower parts. They are soft and fleshy folds of skin lined with mucous membranes, though the skin here is thinner than it is in most other parts of the body. It’s often more sensitive, too, and doesn’t contain hair, sweat glands, or sebaceous glands. Most people have a lot of nerve endings in their lips, and they are usually considered a tactile organ, sensitive to both touch and temperature.

The main job of lips is to assist with the intake of food as it passes into the mouth. Infants and babies often need them to suck and receive milk, and even in older children and adults the lips are one of the main ways that food is drawn into the larger mouth. They also play an important role in keeping things in during chewing and early digestive breakdown. Closed lips provide a relatively tight chamber, keeping food and drink locked firmly inside.

Lips are also really important when it comes to speech and facial expressions. People depend on lip movements to make different sounds and to form words, and they can also play a role in non-verbal communication. A frown can signal displeasure, for instance, while a smile usually relates to happiness, contentedness, or even agreement.

The cavity also includes the tongue and jaw. In humans and most animals, the tongue covers the entire bottom part of the mouth, and it is one of the sensory organs of the human body. It is covered with small pimple-like bumps called taste buds, which enable it to distinguish five different flavors: sweet, bitter, salty, sour, and umami. Aside from this, the tongue helps with the chewing and swallowing of food by keeping it moist and manipulating it from one section of the cavity to the other. The tongue also influences the projection of sounds and speech.

The jaw is a part of the buccal cavity that is critical to the chewing of food. It is made up of a fixed upper jawbone, known as the maxala, and a mobile lower jawbone, known as the mandible. Together these two parts move back and forth to facilitate the tearing and chewing of food by the teeth. Similar to the tongue, movements of the jaw influence speech and communication of sounds, too.

The throat is where the first section of the digestive system ends and the second section begins. It is found at the end of the buccal cavity proper and is made up of the pharynx, larynx, trachea, and esophagus. The throat has multiple functions, the first of which is to enable swallowing in order to control the buildup of excess secretions in the mouth such as saliva and mucus. In the digestive system, the throat moves chewed food from the mouth through the esophagus and into the stomach. Its secondary role is carried out by the larynx, which houses the vocal cords, which are crucial for the production of sounds.