Learning Objective

By the end of this article, learners will be able to identify the types of tonsils in Waldeyer’s ring, describe their anatomical location, blood supply, innervation, and lymphatic drainage, and explain relevant clinical correlations such as tonsillitis and peritonsillar abscess.

Tonsils of the Pharynx – Waldeyer’s Ring

The tonsils are collections of lymphatic tissue located within the pharynx, forming a circular arrangement known as Waldeyer’s ring:

• Pharyngeal tonsil
• Tubal tonsils (x2)
• Palatine tonsils (x2)
• Lingual tonsil

Classified as mucosa-associated lymphoid tissue (MALT), tonsils contain T cells, B cells, and macrophages, serving as a first line of defence against pathogens entering via the nasopharynx or oropharynx.

Lingual Tonsil

• Location: Submucosa of the posterior third of the tongue; forms the inferior part of Waldeyer’s ring.
• Epithelium: Stratified non-keratinised squamous epithelium.
• Blood Supply: Lingual artery, tonsillar branch of facial artery, ascending pharyngeal artery.
• Venous Drainage: Dorsal lingual branch of the lingual vein.
• Innervation: Glossopharyngeal nerve.
• Lymphatic Drainage: Jugulodigastric and deep cervical nodes.

Pharyngeal Tonsil (Adenoids)

• Location: Roof of the nasopharynx; forms the superior part of Waldeyer’s ring.
• Epithelium: Ciliated pseudostratified columnar epithelium.
• Blood Supply: Ascending palatine artery, ascending pharyngeal artery, pharyngeal branch of maxillary artery, artery of pterygoid canal, basisphenoid artery, tonsillar branch of facial artery.
• Venous Drainage: Pharyngeal plexus.
• Innervation: Vagus (X) and glossopharyngeal (IX) nerves.
• Lymphatic Drainage: Retropharyngeal nodes and deep cervical nodes.

Tubal Tonsils

• Location: Around the Eustachian tube opening in the lateral nasopharyngeal wall; lateral aspect of Waldeyer’s ring.
• Epithelium: Ciliated pseudostratified columnar epithelium.
• Blood Supply: Mainly ascending pharyngeal artery.
• Venous Drainage: Pharyngeal plexus.
• Innervation: Maxillary (V2) and glossopharyngeal (IX) nerves.
• Lymphatic Drainage: Retropharyngeal and deep cervical nodes.

Palatine Tonsils

• Location: Lateral walls of the oropharynx, between the palatoglossal (anterior) and palatopharyngeal (posterior) arches; lateral part of Waldeyer’s ring.
• Epithelium: Stratified non-keratinised squamous epithelium.
• Blood Supply: Tonsillar branch of the facial artery.
• Venous Drainage: External palatine vein (into facial vein) and pharyngeal plexus.
• Innervation: Maxillary (V2) and glossopharyngeal (IX) nerves.
• Lymphatic Drainage: Jugulodigastric and upper deep cervical nodes.

Clinical Relevance

Tonsillitis:

• Inflammation of the palatine tonsils is usually viral (≈2/3 cases), bacterial in ~1/3 cases.
• Symptoms: Dysphagia, pyrexia, halitosis, erythematous and swollen tonsils, lymphadenopathy.

Peritonsillar Abscess (Quinsy):

• Complications of bacterial tonsillitis.
• A collection of pus in the peritonsillar space may cause uvular deviation.
• Management:
  • Needle aspiration with ta opical anaesthetic.
  • Incision and drainage, possibly using Magill forceps.

Illustrations:

• Waldeyer’s ring showing all tonsils.
• Lingual and palatine tonsils.
• Peritonsillar abscess with uvular deviation.

Activity