To complete our picture of the upper part of the pharynx, we’ll put the styloid process back, along with two of its three muscles. The longer one is styloglossus, the shorter one is stylopharyngeus.
Stylopharyngeus runs down outside the superior constrictor, and passes into the wall of the pharynx between the superior and middle constrictors. Styloglossus passes downwards and forwards alongside the superior constrictor, and enters the posterior part of the tongue, joining with hyoglossus.
To complete our picture of the pharynx we’ll look at a specimen that’s been divided in the midline. Looking at the pharynx from the inside will also let us see the muscles of the palate that we left out of the picture in the previous section.
Here’s the pharynx. Throughout its length, the back wall of the pharynx lies just in front of the vertebral bodies and the longus muscles, with a layer of loose fascia in between that permits movement. The pharynx opens forwards into the nasal cavity, the oral cavity, and the larynx.
Up here, it opens laterally into the auditory tube as we’ve seen. Down here it opens downward into the esophagus. The pharynx is often described in three parts, the nasopharynx, which we’ve looked at already, the oropharynx, and the hypopharynx, also sometimes called the laryngopharynx.
The muscles of the palate that we haven’t seen yet lie directly beneath the mucosa, which we’ll remove.
Here’s palatoglossus. It arises here from the palatal aponeurosis, and passes downwards and forwards to insert on the side of the tongue. Palatoglossus pulls the soft palate downward and forward.
Here’s palatopharyngeus. It arises partly from the edge of the hard palate, partly from the palatal aponeurosis. Palatopharyngeus passes downwards and backwards to blend with an almost continuous layer of longitudinal muscle that lines the lower part of the pharynx. The lowest fibers of palatopharyngeus insert here, on the posterior border of the thyroid cartilage.
The palatoglossus muscle lies inside the constrictor muscles, hiding them almost completely in this medial view. From here we only see the upper part of the superior constrictor.
We’ll take a closer look at it. Here’s the upper free border of the superior constrictor muscle. Coming in towards us from above are structures we met earlier in this tape, the levator palati muscle, the tensor palati muscle, and the cartilage of the auditory tube.