Pharynx

The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs).

It is found in vertebrates and invertebrates, though its structure varies across species.

The pharynx carries food and air to the esophagus and larynx respectively.

The flap of cartilage called the epiglottis stops food from entering the larynx. In humans, the pharynx is part of the digestive system and the conducting zone of the respiratory system. (The conducting zone—which also includes the nostrils of the nose, the larynx, trachea, bronchi, and bronchioles—filters, warms and moistens air and conducts it into the lungs).

The human pharynx is conventionally divided into three sections: the nasopharynx, oropharynx, and laryngopharynx.

It is also important in vocalization. In humans, two sets of pharyngeal muscles form the pharynx and determine the shape of its lumen.

They are arranged as an inner layer of longitudinal muscles and an outer circular layer.