Final answer:
The stylopharyngeus is a muscle that inserts onto the deep surface of the pharyngeal wall and is important for the elevation and expansion of the pharynx during swallowing. The pharynx extends from the nostrils to the larynx and esophagus, and it's lined by a mucous membrane with a similar structure to the oral cavity.
Step-by-step explanation:
The stylopharyngeus is a muscle that plays a crucial role in the process of swallowing, or deglutition. It originates from the styloid process of the temporal bone and traverses downward to insert onto the deep surface of the pharyngeal wall. This muscle is significant for raising and expanding the pharynx to accommodate a bolus of food. As the elevator skeletal muscles of the pharynx contract, this action allows the stylopharyngeus to help elevate the pharynx during swallowing. After the food is received, the elevator muscles relax, and the constrictor muscles engage to propel the bolus into the esophagus, beginning the peristalsis journey towards the stomach.
The pharynx itself is a short tube that extends from the nostrils to the esophagus and the larynx, lined by a mucous membrane. The oropharynx, a part of the pharynx, has a histological makeup similar to the oral cavity, featuring stratified squamous epithelium with mucus-producing glands. The pharyngeal muscle actions are essential for the safe and efficient movement of food from the oral cavity to the esophagus, while also ensuring that the airways are protected from accidental aspiration of food.