role of the lymphatic system Flashcards
define: lymphatic system
one way system of organs (spleen), glands (thymus), tissues (lymph nodes and bone marrow) and vessels which produce and transport lymph from tissues to the circulatory system
lynmph organs are composed of ______ tissue - why are they named this way
lymphoid tissue, beacuse they contain a lot of lpymphcutes
decsribe lymph vessels
commence at body tissues, goes through lymphoid organs and merges with blood vessels near heart.
how do antigen presenting cells go
from the tissues near potential entry sites through the lymph vessels to the secondary lymph organs
define: primary lymphoid organs
where mature lymphocytes (T and B cells) develop from precursor cells (bone marrow and thymus)
structure of bone marrow?
soft tissue in the hollow centre of long bonds
function of bone marrow?
source of pluripotent stem cells - which produces all blood cells (inc white blood cells, which are all involved in the immune system)
site of development of b cells, and precursor t cells
location of thymus
behind sternum (breast bone) and shrinks with age; T cells develop here
define: secondary lymphoid organs
where mature (naïve) lymphocytes are activated by meeting their complementary antigens and develop into effector cells
location of spleen?
upper left abdomen
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function of spleen?
o Filters blood passing though it – clearing blood of bacteria, viruses and worn out red blood cells.
o Contains T and B cells, as well as other immune cells (macrophages and dendritic cells)
location of lymph nodes?
anywhere except CNS, in high numbers around armpits, groin, neck, abdomen
located along blood vessels (where most t/b cells enter) and lymphatic vessels (fewer enter), giving entry to lymph nodes
funtion of lymph nodes?
o Main site of the specific immune response – T cells, B cells and antigen presenting cells interact with non self antigens here
what happens to lymph nodes during infection?
swell - due to increased numbers of B and T cells there
