Pterygopalatine Fossa and Palate - LO 1

1. What are the major components of the pharyngeal lymphatic (tonsillar) ring? Where do these components typically drain?

The pharyngeal lymphatic (tonsillar) ring, often referred to as Waldeyer’s ring, is located in the superior pharynx.

Four types of tonsils compose this incomplete ring:

The pharyngeal tonsil (adenoid) is located on the roof & posterior wall of the nasopharynx. It achieves maximum size around the age of 5, and atrophies thereafter. The tonsil has an extensive vascular supply including branches from the ascending pharyngeal a., ascending palatine a., pharyngeal branches of the maxillary a.. artery of the pterygoid canal, and tonsillar brs. of facial a. Adenoidectomies are performed for various reasons, often concurrently with a (palatine) tonsillectomy.

The palatine tonsils are sometimes referred to as ‘the’ tonsils, and have an extensive arterial supply derived from the external carotid a. branches: tonsillar a., dorsal lingual brs. of lingual a., and branches from ascending pharyngeal a. The palatine tonsils atrophy with age, and typically, there will be very little lymphoid tissue (if not removed during life) remaining in the area in individuals of advanced age.

The tubal tonsils are located directly posterior to the pharyngotympanic tubes, and are the most variable in shape and appearance.

The lingual tonsil is composed of multiple lymphoid nodules on the posterior aspect of the dorsum of the tongue. These cause the rugose appearance on the back of the tongue.

The lymphatics in this ring typically drain into the jugulodigastric node, which is sometimes referred to as the tonsillar node (tends to enlarge with tonsil inflammation).