Variations of the pharyngeal raphe

The pharyngeal raphe is described traditionally as a straight, continuous, median, fibrous band that provides attachment for and separates each pair of the three constrictor muscles of the pharynx. The posterior wall of the pharynx was dissected in 236 adult human cadavers of the Mongoloid, Caucasoid, and Negroid races. The arrangement of the raphe in each specimen was recorded. The various arrangements of the raphe were then organized into three types (I, II, or III) and eight subtypes (a, b, or c). The raphe was most often (47%) located between the inferior constrictor muscles only (type I) where it was either a straight or a curved line or had a fusiform to oval shape. The second most frequent pattern (40%) was a raphe located between the superior and middle constrictor muscles only (type II) with a shape similar to type I. The middle constrictor muscles were sometimes well developed and attached superiorly to the pharyngeal tubercle by way of a strong raphe. The raphe extended from the pharyngeal tubercle through all the constrictor muscles to the esophagus (type III) in only 13% of the specimens and was more often interrupted rather than a continuous line. The type usually described in anatomy textbooks (type IIIa) was found in only 5% of the specimens.