| Popis: |
In the rat, hemolymph nodes have been studied by light, transmission, and scanning electron microscopy. Their basic structure is similar to that of the normal lymph node. Both have afferent and efferent lymphatics, lymphatic sinuses with macrophages and trabeculae, and lymphoid tissue separable into three distinct zones. The hemolymph node, however, possesses very few afferent lymphatics. It is very vascular and contains capillaries with an attenuated basement membrane. A large number of red blood cells are present focally in the lymphoid parenchyma and diffusely in the lymphatic sinuses, where red blood cells are trapped and subsequently phagocytosed by macrophages. These red blood cells cross the wall of postcapillary venules and that of dilated capillaries between endothelial cells and a narrow gap in the basement membrane. Direct anastomoses between blood vessels and lymphatic sinuses have not been demonstrated. |
