Also known as the oral cavity, the mouth is the secondary external opening to the respiratory tract. As the pathway of air entering the body from the mouth is shorter than the pathway for nose breathing, the mouth does not warm and moisturise the air interring the lungs, as well as the nose. Also, the mouth does not have motile cilia or mucus to filter the passing air like the nasal cavity. An advantage of mouth breathing is the short distance and larger diameter of the passageway; more air can enter quickly.
The parts of the mouth are:
- The oral cavity or mouth cavity is the two jaw ridges called the alveolar arches at the front and sides, containing the teeth.
- The palate, which is the top area of the mouth that separates the mouth from the navel cavity. There are two parts of the palate.
- The soft palate is the back portion of the palate. The soft pallet develops through breastfeeding and has a relation with sucking actions.
- The hard palate is the front portion of the palate
- The tongue is anchored to the floor of the mouth, and at the rear, it forms the ventral wall of the oropharynx part of the pharynx
- The pharynx, known as the throat, is a muscular tube lined with mucous membranes that runs from the skull base to the level of the sixth cervical vertebra and is located at the back of the mouth and connect the mouth, nose and larynx. The pharynx also plays a role in the digestive system. The pharynx is divided into three sections according to location.
- The superior section called the nasopharynx is an air passage posterior to the navel cavity and extends to the region behind the soft pallet of the mouth called the uvula.
- The middle section, called the oropharynx, is a portion of the pharynx posterior to the oral cavity for both air and food and ends just inferior to the tongue.
- The inferior section, called the laryngopharynx, is only for food. It extends from the hyoid bone and lies posterior and to each side of the larynx and merges with the oesophagus.
Mouth breathing while relaxing the tongue and the whole oral cavity can give entry into emotional experiences of the whole body.