Ramos J A, Ramis A J, Rabanal R M, Marco A, Domingo M, Ferrer L M
Department of Animal Pathology, Veterinary Faculty, Autonoma University, Bellaterra, Barcelona, Spain.
Histol Histopathol. 1990 Oct;5(4):397-406.
The aim of this investigation was to study by scanning electron microscopy the structure of several swine lymphoid organs (lymph nodes, Peyer's patches, and tonsil). Two groups of animals were used: six-month-old pigs and six- to nine-day-old piglets. Samples were jet-washed to eliminate most free cells in order to observe the reticular framework of these organs more clearly. Peyer's patches in piglets showed two types of villi. In one of them the cellular types were absorptive cells and goblet cells. The second type of villi were shorter and wider, with M cells characterized by presenting long, thick microvilli over their surfaces. Peyer's patches of pigs did not show this second type of villi but were usually covered by absorptive villi. The soft palate tonsil was similar in both groups of animals with its surface epithelial cells full of microfolds, partially and frequently obscured by microorganisms. The appearance of the surface epithelium in the same crypt was different depending on the area. There was a large number of holes through which cells apparently passed towards the crypt lumen. The medulla in the lymph nodes was at the periphery and showed a dense reticular framework. Cortex-like lymphoid tissue was formed by lymphoid follides and diffuse lymphoid tissue with high endothelid venules and lymphatic sinuses. The serosal surface of lymphoid organs was formed either by a typical mesothelial cell layer (small intestine) or by loosely arranged connective fibers (lymph nodes).
本研究的目的是通过扫描电子显微镜研究几种猪淋巴器官（淋巴结、派伊尔结和扁桃体）的结构。使用了两组动物：6个月大的猪和6至9天大的仔猪。样本经过喷射冲洗以去除大多数游离细胞，以便更清楚地观察这些器官的网状结构。仔猪的派伊尔结显示出两种类型的绒毛。其中一种绒毛中的细胞类型为吸收细胞和杯状细胞。第二种类型的绒毛更短更宽，M细胞的特征是其表面有长而粗的微绒毛。猪的派伊尔结没有显示出这种第二种类型的绒毛，而是通常被吸收性绒毛覆盖。两组动物的软腭扁桃体相似，其表面上皮细胞充满微褶，部分且经常被微生物遮盖。同一隐窝内表面上皮的外观因区域而异。有大量的孔，细胞显然通过这些孔向隐窝腔移动。淋巴结的髓质位于周边，显示出致密的网状结构。皮质样淋巴组织由淋巴滤泡和具有高内皮微静脉和淋巴窦的弥漫性淋巴组织组成。淋巴器官的浆膜表面要么由典型的间皮细胞层（小肠）形成，要么由排列松散的结缔纤维（淋巴结）形成。
