lymphatic system Flashcards
the lymphatic system consists of
lymph
lymphatics
lymphoid tissues and organs
lympocytes
- lymph
similar to plasma but less protein
all cells are bathed in tissue fluid, ECF, which when drained in to lymphatics, it is known as lymph
- lymphatics
lymphatic vessels
begin in peripheral tissues and join to veins
- lymphoid tissues and organs
throughout the body
primary and secondary lymphoid tissues and organs
primary lymphoid tissues and organs
ex. red bone marrow and thymus gland,
where lymphocytes are formed and matured
secondary lymphoid tissues and organs
where lymphocytes are activated and cloned
ex of secondary lymphoid tissues and organs
appendix
spleen
lymph nodes
tonsils
MALT (mucosa-associated lymphoid tissue)
- lymphocytes
which provide immunity against bacteria and viruses
lymphatic vessels are
lymph capillaries
lymph vessels
larger collecting ducts
- lymph capillaries are responsible for the
absorption of interstitial fluid from the tissues
- lymph vessels propel the
fluid upwards to larger collecting ducts
- larger collecting ducts are the
right lymphatic duct
thoracic duct
the right lymphatic duct empties in to the
right subclavian vein
the thoracic duct empties in to the
left subclavian vein
how do lymphatic capillaries differ from blood capillaries?
- originate as pockets rather than continuous vessels
- have larger diameters
- have thinner walls
- have flattened or irregular outline
lymphangitis
inflammation of lymphatic vessels
lymphadenitis
inflammation of lymph node
lymph vessels may be involved in
metastasis (spread) of cancer
lymphedema
(accumulation of interstitial fluid)
occur when lymph is not drained from an area of body
lymphadenopathy
excessive enlargement of lymph node due to bacterial or viral infections, cancer, etc.
lymphatic capillaries are present in almost every
tissue and organ in the body
lymphatic capillaries are absent in
cornea of the eye
red bone marrow
central nervous tissue
internal ear
epidermis of skin
cartilage
bone
lymphatic capillaries are lined by
endothelial cells
lymphatic capillaries’ basement membrane is
incomplete
lymphatic capillaries’ endothelial cells
overlap
forming a valve permitting the fluid to enter with viruses, bacteria, and cell debris but prevent the backflow of these substances
small lymphatic vessels correspond to veins, have
valves which bulge out giving a beaded appearance to the vessels
valves prevent the backflow of
lymph
