The Oropharynx and HypopharynxOropharynx
The oropharynx lies behind the oral cavity, and forms the portion of the pharynx below the nasopharynx, but above the laryngopharynx. This section extends from the uvula which is the end of the palate, to the level of the hyoid bone. The oropharynx opens into the mouth through the isthmus faucium. On the anterior wall of the oropharynx is the base of the tongue and the epiglottic vallecula. The epiglottis, a flap of cartilaginous tissue, covers the glottis when food is being swallowed; this small flap of connective tissue plays a major role in keeping the respiratory tract free from food being inhaled accidentally. On the sides of the oropharynx are two palatine arches, and between these is the palatine tonsil. The roof of the oropharynx is the soft palate and the uvula.
The hypopharynx, which forms the lower third of the pharynx, is also known as the laryngopharynx as it connects the throat to the oesophagus. It is below this point that bifurcation occurs, forming the larynx and oesophagus, and separating the respiratory and digestive routes. The oesophagus is posterior to the larynx and is accommodated by the ability of the trachea to collapse slightly upon food being swallowed due to its C-shaped cartilaginous rings.
Last Updated: 12/31/2010