Anatomy, Head and Neck, Tonsils


Article Author:
Kenneth Masters


Article Editor:
Savita Lasrado


Editors In Chief:
Jasleen Jhajj
Cliff Caudill
Evan Kaufman


Managing Editors:
Avais Raja
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Khalid Alsayouri
Kyle Blair
Trevor Nezwek
Radia Jamil
Erin Hughes
Patrick Le
Anoosh Zafar Gondal
Saad Nazir
William Gossman
Hassam Zulfiqar
Navid Mahabadi
Hussain Sajjad
Steve Bhimji
Muhammad Hashmi
John Shell
Matthew Varacallo
Heba Mahdy
Ahmad Malik
Abbey Smiley
Sarosh Vaqar
Mark Pellegrini
James Hughes
Beata Beatty
Daniyal Ameen
Altif Muneeb
Beenish Sohail
Nazia Sadiq
Hajira Basit
Phillip Hynes
Komal Shaheen
Sandeep Sekhon


Updated:
3/30/2019 2:16:13 PM

Introduction

Tonsils are lymphoid tissue aggregates situated near the entrance of the digestive and respiratory tracts and play a key role in our immune system. They act as a front-line defense forming the initial immunological response to inhaled or ingested pathogens. The lymphatic tissues located in the oropharynx are composed of a circumferential tonsillar ring, known as the Waldeyer's ring which consists of the palatine tonsils (faucial tonsils), adenoid (nasopharyngeal tonsil), lingual tonsil, and tubal tonsils. When patients and doctors discuss tonsils, they are often referring to the palatine tonsils located at the back of the throat between the two palatine arches (pillars). 

Structure and Function

Like all lymphoid tissue, tonsils play a role in the immunity and body's defense against infections and foreign pathogens. The immunologic function of the tonsils is noteworthy.[1] When antigens are inhaled or ingested, tonsils are appropriately positioned for exposure which will lead to the development of lymphokines and immunoglobulins. Composed predominately of B-cell lymphoid tissue, one of the roles served by tonsils is that of mucosal secretory immunity. On the surface of the tonsils, one can find specialized antigen capture cells referred to as M cells. These cells permit the capture of antigens generated by micro-organisms. The M cells, after recognizing an antigen, activate T and B cells in the tonsils and trigger an immune response.[2] B cells, when stimulated, proliferate in the germinal areas of the tonsils. At the germinal center, B memory cells mature and are stored for repeated exposure to the same antigen.[3] B cells also serve to secrete IgA, an antibody that plays a vital role in the immune function of mucus.[4] Newer studies indicate that tonsils also generate T lymphocytes, but the mechanism of production is different compared to the thymus.[5]

Tonsils share common structure and function with other lymphatic tissues located within the gastrointestinal tract (Peyer's patches) which monitor intestinal bacteria populations and prevent the overgrowth of intestinal bacteria.

Embryology

Tonsils are derivatives of the 2nd pharyngeal pouch.[6] They typically appear around the 4th or 5th months of gestation and continue to develop with the growth of the child.[7] Present at birth, tonsils tend to reach the full size between the 6th and 8th years of life. Tonsils and adenoid tissue are found to be the most immunologically active between the 4th and 12th years of life and begin to involute/atrophy shortly after the first decade.[8]

Blood Supply and Lymphatics

  • Tonsils lie along the lateral wall of the oropharynx, in a fossa located between the anterior and posterior pillars. Five arteries provide blood supply to the tonsils. They include the tonsillar branch of the facial artery (main supply), ascending palatine artery, dorsal lingual artery, ascending pharyngeal artery, and lesser palatine artery.[9] The venous drainage of the tonsils occurs primarily through the peritonsillar plexus of veins into the pharyngeal and lingual veins which drain into the internal jugular vein.[6]
  • While not providing direct blood supply to the tonsils, it is important to note that the internal carotid artery is approximately 2.5cm posterolateral to the tonsils and requires precaution during surgeries to avoid accidentally cutting it.

Nerves

  • Tonsils receive the afferent supply from the tonsillar plexus, with contributions from the trigeminal nerve (CN 5) via the lesser palatine nerves, as well as the glossopharyngeal nerve (CN IX).
  • CN IX continues distally to the tonsils supplying general sensory and taste sensation to the posterior one-third of the tongue. CN IX is the nerve most likely to be damaged during a tonsillectomy.

Surgical Considerations

Tonsillectomy

  • Surgical removal of tonsils is called tonsillectomy.
  • Hemorrhagic tonsillitis is an absolute indication for tonsillectomy.[10]
  • Relative indications for tonsillectomy include[10]:
    • Recurrent or chronic pharyngotonsillitis
    • Peritonsillar abscess
    • Streptococcal carriage 
  • Tonsils are surgically removed by dissecting between the tonsillar capsule and the superior constrictor muscle using either the “hot” or “cold” technique.  In the “hot” tonsillectomy technique, electrocautery is employed to dissect and coagulate simultaneously. In the “cold” tonsillectomy technique, a superior incision is made through the mucosal layers, and blunt dissection is used to separate the tonsils from the underlying tonsillar bed. Tonsils are then separated along its inferior border using the snare method. Studies have shown a superiority of the cold technique when looking at the outcome of postoperative pain. However, electrocautery minimizes intraoperative blood loss.[11] Newer techniques currently in practice employ the use of CO2 lasers, ultrasound, as well as radiofrequency ablation citing reduced postoperative pain though further research is necessary.
  • Complications following a tonsillectomy classify into three main categories: acute, subacute, and delayed. Acute complications include airway obstruction due to edema, bleeding, and post-obstructive pulmonary edema. Subacute complications include postoperative hemorrhage, dehydration, and weight loss. Delayed or chronic complications include velopharyngeal insufficiency and nasopharyngeal stenosis.[11]
  • Good practice advocates that the serious complications of tonsillectomy (profuse hemorrhage requiring blood transfusion and potentially fatal hemorrhage) be routinely discussed during the process of obtaining informed consent for tonsillectomy, despite their low occurrence rate. 'Reasonable patients' consider these complications to be significant and expect surgeons to discuss these complications with them. Surgeons, however, on the other hand, avoid discussing these serious complications with their patients.[12]
  • The literature reports cases of fatality from massive hemorrhage as a result of tonsillectomy.[13][14]

Adenotonsillectomy

  • In certain conditions, both tonsillectomy and adenoidectomy (surgical removal of the adenoid) are indicated.[15]
  • Surgical excision of both the tonsils and adenoid is referred to as adenotonsillectomy.
  • Absolute indications for adenotonsillectomy include[10]:
    • Adenotonsillar hyperplasia with obstructive sleep apnea
    • Abnormal dentofacial growth
    • Malignancy
  • Dysphagia, speech impairment, and halitosis are relative indications for adenotonsillectomy.[10]
  • Removal of the tonsils and adenoid does not produce any clinically significant immunologic deficiency.
  • Various acquired or inherited bleeding disorders, anemia, acute infection and patients with high anesthetic risk are contraindications for adenotonsillectomy.[11]

Clinical Significance

Tonsilloliths

Tonsilloliths (tonsil stones) are whitish, malodorous concretions that develop in the tonsillar crypts arising from bacterial growth and retained cellular debris. They are most often asymptomatic but may lead to issues including halitosis, otalgia, and foreign body sensation. Management is conservative, and patients are encouraged to extract tonsilloliths by using cotton swabs. However, large troublesome tonsilloliths require surgical extraction. Mouth rinses and gargling may be beneficial in combating halitosis caused by tonsilloliths.[16]

Bacterial Tonsillitis

Acute bacterial tonsillitis may present with the sudden onset of throat pain, enlarged erythematous or exudative tonsils, malodorous breath, and tender cervical lymph nodes. It may be challenging to differentiate bacterial from viral etiologies of tonsillitis/pharyngitis. While the treatment of viral disease is mainly supportive care, the treatment of routine, mild tonsillitis is pain control and antibiotics (amoxicillin or macrolides). For recurrent tonsillitis, tonsillectomy is the recommended course. Current guidelines provided by the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) recommend surgical intervention for recurrent tonsillitis when a patient is found to have suffered seven infections in one year, five infections per year for two years, or three infections per year for three consecutive years.[17]

Adenotonsillar Disease

Adenotonsillar disease includes recurrent tonsillitis and adenoiditis. Patients can present with both acute and chronic infections of the adenoid. Infections of the adenoid are often mistaken for viral and bacterial upper respiratory infections as symptoms overlap and are difficult to differentiate. Adenoiditis is likely to present with fever, purulent nasal drainage, nasal obstruction and is commonly associated with otalgia. Group A beta-hemolytic streptococcus (GABHS, Streptococcus pyogenes) is a common cause of acute tonsillitis. Chronic inflammation of the tonsils and adenoid can result in hypertrophy. Adenoid hypertrophy may play a role in causing obstructive sleep apnea.[18]

Peritonsillar Abscess

Peritonsillar abscess is also called quinsy.[19] It is a collection of purulent fluid in the space surrounding the tonsils between the tonsillar capsule and the superior constrictor muscle. An abscess develops when an infection penetrates the capsule and enters the peritonsillar space. Presenting signs and symptoms of peritonsillar abscess include dysphagia, odynophagia, trismus, and a classic “hot potato” or muffled voice. Physical examination of the oral cavity will expose enlarged infected tonsils, a bulging soft palate (superiorly), and often reveals unilateral deviation of the uvula towards the side contralateral to the infection. Management may include needle aspiration in the clinic or emergency room, which has been shown to be effective in as high as 90% of cases. Antibiotics are recommended following needle aspiration and emphasis is placed on those with strong gram-positive coverage such as clindamycin. Tonsillectomy should be reserved for recurrent peritonsillar abscess and should only take place following the resolution of infection.[20]


  • Image 9802 Not availableImage 9802 Not available
    Image courtesy S Bhimji MD
Attributed To: Image courtesy S Bhimji MD

Interested in Participating?

We are looking for contributors to author, edit, and peer review our vast library of review articles and multiple choice questions. In as little as 2-3 hours you can make a significant contribution to your specialty. In return for a small amount of your time, you will receive free access to all content and you will be published as an author or editor in eBooks, apps, online CME/CE activities, and an online Learning Management System for students, teachers, and program directors that allows access to review materials in over 500 specialties.

Improve Content - Become an Author or Editor

This is an academic project designed to provide inexpensive peer-reviewed Apps, eBooks, and very soon an online CME/CE system to help students identify weaknesses and improve knowledge. We would like you to consider being an author or editor. Please click here to learn more. Thank you for you for your interest, the StatPearls Publishing Editorial Team.

Anatomy, Head and Neck, Tonsils - Questions

Take a quiz of the questions on this article.

Take Quiz
Which vessel comprises the major blood supply to the tonsils?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
The palatine tonsil receives blood supply from which of the following arteries?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Antigen capture cells located on the surface of tonsils are known as which of the following?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 10 year old female presented to her provider, complaining of cough, pain in throat, and sore throat since 5 days. Physical examination revealed swelling noted in the picture. Which nerves innervates the affected area?

(Move Mouse on Image to Enlarge)
  • Image 9802 Not availableImage 9802 Not available
    Image courtesy S Bhimji MD
Attributed To: Image courtesy S Bhimji MD



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
What branch does the artery which supplies the main blood supply to the palatine tonsil come from?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up

Anatomy, Head and Neck, Tonsils - References

References

Hellings P,Jorissen M,Ceuppens JL, The Waldeyer's ring. Acta oto-rhino-laryngologica Belgica. 2000     [PubMed]
Jović M,Avramović V,Vlahović P,Savić V,Veličkov A,Petrović V, Ultrastructure of the human palatine tonsil and its functional significance. Romanian journal of morphology and embryology = Revue roumaine de morphologie et embryologie. 2015     [PubMed]
Carrillo-Ballesteros FJ,Oregon-Romero E,Franco-Topete RA,Govea-Camacho LH,Cruz A,Muñoz-Valle JF,Bustos-Rodríguez FJ,Pereira-Suárez AL,Palafox-Sánchez CA, B-cell activating factor receptor expression is associated with germinal center B-cell maintenance. Experimental and therapeutic medicine. 2019 Mar     [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]
    [PubMed]

Disclaimer

The intent of StatPearls is to provide practice questions and explanations to assist you in identifying and resolving knowledge deficits. These questions and explanations are not intended to be a source of the knowledge base of all of medicine, nor is it intended to be a board or certification review of Optometry-Basic Science. The authors or editors do not warrant the information is complete or accurate. The reader is encouraged to verify each answer and explanation in several references. All drug indications and dosages should be verified before administration.

StatPearls offers the most comprehensive database of free multiple-choice questions with explanations and short review chapters ever developed. This system helps physicians, medical students, dentists, nurses, pharmacists, and allied health professionals identify education deficits and learn new concepts. StatPearls is not a board or certification review system for Optometry-Basic Science, it is a learning system that you can use to help improve your knowledge base of medicine for life-long learning. StatPearls will help you identify your weaknesses so that when you are ready to study for a board or certification exam in Optometry-Basic Science, you will already be prepared.

Our content is updated continuously through a multi-step peer review process that will help you be prepared and review for a thorough knowledge of Optometry-Basic Science. When it is time for the Optometry-Basic Science board and certification exam, you will already be ready. Besides online study quizzes, we also publish our peer-reviewed content in eBooks and mobile Apps. We also offer inexpensive CME/CE, so our content can be used to attain education credits while you study Optometry-Basic Science.