Lymphoid Flashcards
2 main lymph organs of early life
- thymus
2. bone marrow
2 main different lymphocytes and what they do
B - respond to specific antigen with antibody
T - some attack antigens and others regulate responses
2 main types of lymph tissues and where
- Primary - marrow and thymus
2. secondary - diffuse, spleen, lymph nodes
Path of t-cell dev.
marrow> thymus where devs. antigen receptor>periphery
path of B-cell dev.
marrow>dev. immucometence>periphery
2 main parts of thymus
cortex - dark with many small lymphocytes
medulla - lighter with fewer lymphocytes
cells that line the capsule
epithelioreticular cells
- connect by desmosomes
- creates blood thymus barrier
fate of T-lymphocytes in thymus
5% dev. proper T-cell receptor, the rest are apop and macrophaged
what divides the lobules in thymus
trabeculae
what are hassal’s corpuscles
large centers that fill up with keratin
3 types of diffuse lymph tissue
- lymph nodules - germinal centers where activated lymph differentiate
- tonsils - encapsulade in pharynx
- peyer’s patches - in illeum
features of lymph nodes
- fibrous capsule with penetrating trabeculae
- sinuses where afferent lymph dumped
- dendritic cells are antigen presenters
- medulary cords - with T and B and plasmas
what is special about post-capillary venules
- lined with cuboidal cells instead of squamous
- tells lymph to leave blood and enter node
features of spleen
- detect and respond to blood born antigens
- remove old RBCs and platelets
2 types of spleen tissue
- white pulp - central arteries with T and B lymphocytes
2. Red pulp - splenic sinuses - arterioles, RBCs, macrophages, and reticular cells
