腸管のリンパ装置（マクロ解剖学）

Lymphatic Apparatus in the Intestine: Its Macroscopic Anatomy

要旨　腸管にみられるリンパ装置は，リンパ小節の形態をとり，小腸あるいは大腸の粘膜内，および粘膜から粘膜下組織にかけて存在する．1個のリンパ小節から成るものを孤立リンパ小節と呼び，肉眼的にも，粘膜表面から小さな粒子として腸絨毛の間に，また，大腸では粘膜の凹みとして認められる．リンパ小節が多数集まったものを集合リンパ小節またはパイエル板と呼ぶ．大腸ではほとんど存在せず，小腸に分布し，特に終末回腸部に多い．パイエル板の大きさ，分布数などは一定しないが，パイエル板の存在する所では，輪状ひだが消失している．リンパ小節は，思春期まで増加し，以後加齢と共に減少する．肉眼的に認めにくい小節もかなり存在する．

　There are two types of lymphatic nodules in the intestine; solitary type and aggregated type. The latter is confined mostly to the small intestine, particularly in the terminal ileum. Solitary nodules are observed macroscopically as fine granules of about 1-2 mm in diameter in discrete form throughout the entire intestine. Smaller nodules are present in the lamina propria but larger ones may bulge into the submucosa. Aggregated nodules, also known as Peyer's patches, are composed of variable numbers of nodules resulting in the sizes varying from 1 to 30 cm in length. These nodules are not covered with intestinal villi in the small intestine but look like a dome in the midst of intestinal villi. Some of these nodules, however, are embedded deeply in the mucosa and covered with intestinal villi, thus making them difficult to detect. Development of these nodules reaches the maximum at the puberty and then gradually declines with age.