Unit I

Palatine Tonsil (LP): A lymphoid tissue covered by a mucous membrane is called as a tonsil. There arelingual, pharyngeal, palatine and abdominal tonsils in the body. The tonsil usually means palatine tonsilunless specified otherwise.The tonsil is covered on the oral side by the stratified squamous nonkeratinised epithelium, whichdips into the underlying lymphatic tissue to form 10 to 20 little pits or primary crypts. A primary pit mayshow many secondary pits. In the lamina propria the lymphatic tissue is arranged in the form of lymphaticnodules that extend along the sides of the crypts. In these lymphatic nodules there is loose lymphaticconnective tissue with many plasma cells. In the lamina propria some mucous glands are seen and theirducts open on the surface and not at the bottom of the tonsillar crypts. As the crypts are difficult to beflushed out, tonsillitis occurs commonly due to accumulation of debris Part of striated muscle coat ofpharynx may be seen in transverse section.Notes:53