smallest lymphatic vessels, begin as microscopic blind ended vessels, resemble blood capillaries but more porous
2 features that allow lyphatic capillaries to take up fluid.
Flaplike minivalves and collagen filaments
specialized lymph capillaries that occur in fingerlike projections, extend into small intestine
form as lymph capillaries merge.
lymphatic collecting vessels
from the union of collecting vessels, major trunks named from regions from which they drain.
largest lymphatic vessels. drain lymph into veins in the neck.
collects lymph from the upper right side of the body, right arm and right regions of thorax, neck and head.
right lymphatic duct
collects lymph from the left side of the body and regions from the right side of the body below the thorax.
enlarged region of the lymphatic vessel that forms following in the union of the intestinal trunk and rt and lt lumbar trunks.
WBC that provide an immune response that attacks specific kinds of nonself cells.
originate in bone marrow, mature in the thymus glandattack self cells that have been invaded by pathogens, abnormal selfcells or nonself cells.
originate and mature in bone marrow. they produce plasma cells.
capture antigens and then migrate to the lymph nodes where they interact with T cells and B cells ot initiate and shape the immune response
play an important role in body protection and in activating T lymphocytes
produce the stroma, network that supports the other cell types in the lymphoid tissue
unencapsulated bundles of lyphatic cells. consists of lymphocytes and macrophages associated with the reticular fiber network. occurs in the middle layer of the mucus membranes that line the respiratory and digestive tracts.
diffuse lymphatic tissue.
unencapsulated bundles of lymphatic cells. line the gastrointestinal, respiratory, reproductive and urinary tracts. protect passages that are open to the exterior from the never ending invasion of pathogens.
Lymphatic nodules (follicles)
clusters of lymphatic nodules that occur in the mucus membranes that line the ileum and small intestine.
aggrgates of the lymphatic nodules that occur in the mucus membranes that lines the pharynx
single tonsil in the reaar wall of the nasopharynx
tonsils on each side of the oral cavity at its entrance to the throat.
tonsils at the base of the tongue
small fingerlike attachment to the begining of the large intestines.
other lymphoid organs
spleen and thymus
largest lymphatic organ, filters blood, destroys old red blood cell and recylcles their parts. provides a reservior of blood, produces blood cells.
2 distinct areas of the spleen
white pulp, consists of reticular fibers, resembles lymph nodes,
red pulp, consists of venous sinuses filled with blood.
bi lobed, grows during childhood and reaches its maximum size at puberty, slowly decreases in size as it is replaced by adipose and areolar connective tissue, promotes the maturation of T lymphocytes through the secretion of thymopoietin and thymosin.