Department of Anatomy, Xuzhou Medical College, Xuzhou, Jiangsu, China
The lymphatic system consists of the lymphatic vessels (capillary plexus, precollecting and collecting lymph vessels including lymphatic ampullae and diverticulum and lymphatic trunks and ducts), organs (lymph nodes, spleen, thymus and tonsils), tissue (Peyer’s patch), etc. Relevant terminology regarding the components of the lymphatic system and newly discovered structures is listed and described in this chapter (Figs. 1.1 and 1.2).
Components and reflux of the lymphatic pathway
A sketch map of the basic lymphatic pathway in the scalp. (a) Lymph capillary plexus originates from both the dermis and galeal layer to unite a precollecting lymph vessel that runs either directly or indirectly for a short distance before entering a collecting vessel in the subcutaneous tissue. (b) The basic lymphatic pathway in the scalp. (c) A magnified view of the basic lymphatic pathway in the scalp, showing the relationship among the lymph capillary plexus, precollecting and collecting lymph vessels, lymphatic ampullae, and lymph nodes
1 Lymph Capillary Plexus
Originating with the blind ends, two layers of the lymph capillaries have been observed, one on shallow and one on deeper parts in the dermis (Fig. 1.3) and mucosa (Fig. 2.64). They are connected to form a three-dimensional network – the lymph capillary plexus. They are also named as the initial lymphatics in some literatures (Földi et al. 2003; Shayan et al.2006).
A schematic diagram of connections among the capillary lymphatic plexus and precollecting and collecting lymphatic vessels in the skin
2 Precollecting Lymph Vessel
Precollecting lymph vessels connect the lymph capillary plexus and collecting lymph vessels. They arise from the deep side of the dermis, mucosal and the galeal layer, etc., travel from the superficial to deeper layer of the subcutaneous tissue in different directions and then drain to the collecting lymph vessels (Figs. 1.2 and 1.3).