Tonsillectomy with or without adenoidectomy is the second-most common surgery of childhood, but is less commonly performed in adults. Tonsillectomy accounts for 25% of all operations performed by otolaryngologists (ear, nose and throat surgeons).

Anatomy and Physiology

• They are generally ovoid or bilobed tissue collections with a very irregular surface
  
• They are found between the front and back tonsillar arches, located along the sides of the pharynx (back of the throat) (Figure 1). The tonsillar fossa is the depression between the arches in which the tonsil lies
  
• The tonsils are highly vascular (contains many blood vessels), which helps them to perform their function of protecting against infection, as foreign material enters the body through the mouth. The blood supply comes from several branches of the external carotid artery (Figure 2)
  
• The nerve supply is mainly from the ninth cranial nerve, which provides sensation to much of the throat. This nerve also supplies sensation to a small part of the ear, which explains why ear pain is frequently associated with throat infections or experienced after tonsillectomy
  
• The adenoids are lymphoid tissue at the back of the throat and above the palate
  

Figure 1 - Open mouth view of the tonsils. The tonsils are rounded masses of lymphoid tissue on each side of the pharynx. The palate is the roof of the mouth. In the center of the back of the palate hangs a soft finger of tissue, the uvula. The lowest portion of enlarged adenoids is seen behind and just below the palate ©Rob Gordon	Figure 2 - The tonsil is very vascular and gets blood from several branches of the external carotid artery