medullary sinuses - drain lymph to the efferent lymph vesselĬervical - superficial (parotid, mastoid, occipital) and deep nodes
![blind ended vessel meaning blind ended vessel meaning](https://i.ytimg.com/vi/ZS84LpFAxPc/maxresdefault.jpg)
![blind ended vessel meaning blind ended vessel meaning](https://petrofilm.com/yahoo_site_admin/assets/images/kish_island_iran.29124452_std.jpg)
medullary cords - plasma cells, small lymphocytes and macrophages Paracortex - CD4 and CD8-T cells, migrating dendritic cells secondary nodule - activated B-lymphocites form germinative center with dark zone (centroblasts), light zone (centrocytes) and mantle zone (small quiescent cells) Hilum - passage for the artery, vein, afferent and efferent lymph vesselsĬapsule - surrounding dense connective tissue Secondary: lymph nodes, spleen, MALT, Peyer's patches The average young adult has about 450 lymph nodes throughout the body most of which are in the abdominopelvic region, then the thorax and the remainder in the head and neck. For the sake of completeness, other secondary lymphoid organs include (but are not limited to) the spleen, mucosa-associated lymphoid tissue (MALT), tonsils, and Peyer’s patches. They are strategically located at areas that are open to foreign microorganisms (e.g.
![blind ended vessel meaning blind ended vessel meaning](https://www.worldatlas.com/r/w1200-h701-c1200x701/upload/b5/a1/31/100029-lus-00-lusitaniasinkcolour.jpg)
Lymph nodes are secondary lymphoid organs widely distributed throughout the body. They can be classified as either primary lymphoid organs (bone marrow and thymus) where de novo synthesis and maturation of lymphocytes occur or secondary lymphoid organs where activation of lymphocytes occur. Lymphoid tissues are collections of lymphocytes strategically located at potential sites of infection.