Tonsils.pptx

ANATOMY OF THE TONSILS August 2024 Jason G. Ngalob, MD, DPBS, FAMP, FPSGS, FPCS General and Cancer Surgeon Professor of Surgery and Anatomy Immediate Past-Chairman, Department of Surgery Saint Louis University – School of Medicine Training Officer, Dep...

ANATOMY OF THE TONSILS August 2024 Jason G. Ngalob, MD, DPBS, FAMP, FPSGS, FPCS General and Cancer Surgeon Professor of Surgery and Anatomy Immediate Past-Chairman, Department of Surgery Saint Louis University – School of Medicine Training Officer, Department of Surgery Saint Louis University – Sacred Heart Medical Center Examiner Philippine Board of Surgery Tonsils - are classified as mucosa-associated lymphoid tissue (MALT), and therefore contain T cells, B cells and macrophages - have an important role in fighting infection – the first line of defense against pathogens entering the nasopharynx or oropharynx - collectively form a ringed arrangement, known as Waldeyer’s ring: 1. Adenoid or pharyngeal tonsil (x1) 2. Tubal tonsils (x2) 3. Palatine tonsils (x2) 4. Lingual tonsil (x1) Adenoid tonsils - the adenoid, also known as a pharyngeal or nasopharyngeal tonsil, is situated posterior to the nasal cavity, in the roof of the nasopharynx, at the midline and forms the superior aspect of Waldeyer’s ring - Normally, in children, it forms a soft mound in the roof and posterior wall of the nasopharynx, just above and behind the uvula; in adults it becomes an inconspicuous part of the wall of the pharynx l (1) Blood Supply, Venous Drainage, and Innervation - Primary BS 1. Ascending palatine artery (FA) 2. Ascending pharyngeal artery (ECA) 3. Pharyngeal/descending branch of the maxillary artery 4. Basisphenoid artery (infHypophyA) 5. Tonsillar branch of the facial artery - VD is via the pharyngeal plexus - receives nerve fibers from the vagus and glossopharyngeal cranial nerves Clinical Points Adenoid hypertrophy - In certain cases, the adenoids can become infected in young children and do not atrophy significantly even when the infection is gone - This enlargement can affect nasal breathing, resulting in a nasal voice, and mouth breathing - They can also cause problems with sleep, and cause apneic episodes (obstructive sleep apnea) or restlessness Eustachian tube dysfunction - The auditory (a.k.a. Eustachian) tube connects the middle ear to the nasopharynx - Enlarged and inflamed adenoids may block this passageway and can cause infection of the middle ear (i.e. otitis media) and secondary hearing loss Tubal tonsils - refer to lymphoid tissue around the opening of the Eustachian tube in the lateral wall of the nasopharynx - AKA Eustachian or Gerlach tonsils - form the superolateral aspect of the Waldeyer’s ring - The vascular supply is similar to other structures in the nasopharynx, and is chiefly via the ascending pharyngeal artery and venous drainage is to the pharyngeal plexus - innervation is from the maxillary nerve and glossopharyngeal nerve Clinical Points - the location of the tubal tonsils logically suggests that a potential inflammatory obstruction of the eustachian tube prediposes the patient to recurrent otitis media or otitis media with effusion - in this situation, the patient may require surgical removal of the tubal tonsils to clear the obstruction and prevent future otitis infections Palatine tonsils - The palatine tonsils are commonly referred to as ‘the tonsils‘; AKA faucial tonsils - They are located within the tonsillar bed of the lateral oropharynx wall – between the palatoglossal arch (anteriorly) and palatopharyngeal arch (posteriorly) - they form the inferolateral part of the Waldeyer’s ring - each tonsil has free medial surface which projects into the pharynx and hence can be seen with direct examination Blood Supply, Venous Drainage, and Innervation - arterial supply to the tonsil is via the tonsillar branch of the facial artery; the artery pierces the superior constrictor muscle to reach the palatine tonsil - venous drainage is via the external palatine vein (drains into the facial vein), and numerous smaller vessels which drain into the pharyngeal plexus - innervation is from the maxillary nerve and glossopharyngeal nerve Clinical Points - Most palatine tonsillitis cause swelling of the palatines, fever and sore throat; classical fever is high-grade, and in children may cause benign febrile convulsions - Halitosis is a common presentation when abscess develops from the infected tonsils - Deaths have been reported in untreated palatine tonsillitis because of airway obstruction and/or sepsis - Acute tonsillitis caused by group A beta- hemolytic streptococci, in rare cases, causes rheumatic fever and rheumatic heart disease - Rheumatic heart disease (RHD) is a life-threatening heart condition which results from damage to heart valves caused by one or several episodes of rheumatic fever, an autoimmune inflammatory reaction to infection with streptococcal bacteria (streptococcal pharyngitis Lingual tonsils - refers to numerous lymphoid nodules located within the submucosa of the posterior third of the tongue - is responsible for the irregular appearance of the posterior tongue surface - forms the inferior part of Waldeyer’s ring - arterial supply to the lingual tonsil is largely via the lingual artery, with contributions from the tonsillar branch of the facial artery and the ascending pharyngeal artery - The dorsal lingual branch of the lingual vein performs the venous drainage - innervation is from the glossopharyngeal nerve Clinical Points - is a common condition that can affect both adults and children - in some cases, the infection can also lead to more serious complications, such as obstructive sleep apnea or airway obstruction - lingual tonsillitis is most often the result of a viral infection, but fungal or bacterial tonsillitis can also occur - Most infections DO NOT require surgery as majority are responsive to medications