Pharynx


The pharynx, also known as the throat, is a vital structure involved in both digestion and respiration [[1]](https://poe.com/citation?messa....ge_id=97640347802&am It serves as a passageway for food and air, receiving them from the mouth and nasal cavities [[1]](https://poe.com/citation?messa....ge_id=97640347802&am When food enters the pharynx, involuntary muscle contractions occur, closing off the air passageways [[1]](https://poe.com/citation?messa....ge_id=97640347802&am

The pharynx is a short tube composed of skeletal muscle and lined with a mucous membrane [[1]](https://poe.com/citation?messa....ge_id=97640347802&am It extends from the posterior oral and nasal cavities to the opening of the esophagus and larynx [[1]](https://poe.com/citation?messa....ge_id=97640347802&am The pharynx has three subdivisions: the nasopharynx, oropharynx, and laryngopharynx [[1]](https://poe.com/citation?messa....ge_id=97640347802&am The nasopharynx is primarily involved in breathing and speech, while the oropharynx and laryngopharynx are used for both breathing and digestion [[1]](https://poe.com/citation?messa....ge_id=97640347802&am

During swallowing, the muscles of the pharynx contract, raising and expanding the pharynx to receive the bolus of food [[2]](https://poe.com/citation?messa....ge_id=97640347802&am Once received, these muscles relax, and the constrictor muscles of the pharynx contract, forcing the bolus into the esophagus and initiating peristalsis [[2]](https://poe.com/citation?messa....ge_id=97640347802&am The soft palate and uvula rise reflexively to close off the entrance to the nasopharynx, preventing food from entering the nasal cavity [[2]](https://poe.com/citation?messa....ge_id=97640347802&am At the same time, the larynx is pulled superiorly, and the epiglottis folds inferiorly, effectively blocking access to the trachea and bronchi [[2]](https://poe.com/citation?messa....ge_id=97640347802&am

It's important to note that if food "goes down the wrong way" and enters the trachea, the natural reaction is to cough, which usually forces the food back into the pharynx and out of the trachea [[3]](https://poe.com/citation?messa....ge_id=97640347802&am

If you would like to visualize the pharynx and its subdivisions, you can refer to Figure 23.12 in [[1]](https://poe.com/citation?messa....ge_id=97640347802&am This diagram provides a clear illustration of the pharynx and its relationship to other structures.

I hope this information helps you understand the role and anatomy of the pharynx. If you have any further questions, feel free to ask!