<Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> The pharynx (plural: pharynges) is the part of the throat that is behind the mouth and nasal cavity and above the esophagus and the larynx, or the tubes going down to the stomach and the lungs . The pharynx is an organ found in vertebrates and invertebrates, though the structure is not universally the same across all of those species . </P> <P> In humans the pharynx is part of the digestive system and also of the conducting zone of the respiratory system . (The conducting zone also includes the nostrils of the nose, larynx, trachea, bronchi, and bronchioles, and their function is to filter, warm, and moisten air and conduct it into the lungs .) The pharynx makes up the part of the throat situated immediately behind the nasal cavity, behind the mouth and above the esophagus and larynx . The human pharynx is conventionally divided into three sections: the nasopharynx, the oropharynx and the laryngopharynx . It is also important in vocalization . </P> <P> In humans there are two sets of pharyngeal muscles that form the pharynx, determining the shape of its lumen . These are arranged as an inner layer of longitudinal muscles and an outer circular layer . </P>

What are the 3 regions of the pharynx