Lymphatic System Flashcards
Lymphatic System
collect lymph and filters it through lymph nodes and then returns it to the bloodstream
Lacteals
in villi of SI
absorb lipids from intestines
Chyle
lymph collected by lacteals
Functions of Lymphatic System
drains interstitial fluid from tissue spaces
transports dietary lipids from GI tract to blood
Protects against invasion thru immune response
Lymphatic Capillaries
closed ended vessels b/t tissue cells
Lymphatic Vessels
runs next to A (in viscera) or V (in subcutaneous tissue)
Places where there are no Lymphatic Vessels
CNS, bone marrow, teeth, avascular tissues (cornea)
Vasa Vasorum
supply lymphatic vessels with nutrients
Differences from Lymphatic Vessels to Veins
closed ended larger thinner tunics anchoring filaments ends of endothelial cells making up walls overlap
Flow of Lymph
Interstitial Spaces- L. Capillaries- L Vessels- L Trunks- L. Ducts- Subclavian V- Arteries- Blood Capillaries
9 Lymphatic Trunks
Lumbar, Jugular, Subclavian, Bronchomediastinal- paired
Intestinal- single trunk
Lymphatic Trunks pass lymph to….
Thoracic Duct and Right Lymphatic Duct
Cisterna Chyli
Intestinal Trunk + R and L Lumbar Trunk
Thoracic Duct and R Lymphatic Duct drainage
L and R Subclavian V
Control of flow of lymph from tissue space
contraction of skeletal muscles
valves
Primary Lymphatic Structures
Red Bone Marrow
Thymus Gland
make T, B, NK cells
Major Secondary Lymphatic Structures
lymph nodes, spleen, lymphatic nodules
most immune response
T-Cells
Attack fungi, transplanted cells, cancer cells
B-Cells
destroy bacteria
Natural Killer Cells
attack spontaneously arising tumor cells
Thymus
promote maturation of T-cells
secretes thymosin
Thymosin
assists in promoting proliferation and maturation of T-cells
Why do the Thymus and Spleen not have a filtering function?
they have no afferent lymphatic vessels
White Pulp
part of spleen
mostly B-cells around central arteries
Red Pulp
part of spleen
venous sinuses w/ blood
splenic cords b/t sinuses
White Pulp Function
B-cell proliferation into plasma cells
Red Pulp Function
phagocytosis of bacteria and bad RBCs and platelets
platelet reservoir
Cortex of Lymph Nodes
outer region of densely packed T-cells and immature B-cells
Medulla of Lymph Nodes
inner region of mature B-cells
Germinal Centers of Lymph Nodes
contains masses of proliferating lymphocytes
Medullary Cords of Lymph Nodes
inward extensions from cortex to hilum
T-cells, B-cells, macrophages
Afferent Lymphatic Vessels
carry lymph from tissues to lymph nodes
Efferent Lymphatic Vessels
carry lymph from hilum to venous circulation
Macrophages
destroy foreign substances by phagocytosis
Lymphocytes
destroy foreign substances by immune response
Lymphatic Nodules
no capsule
clusters of lyphocytes in all mucous membranes
Peyer’s Patches
lymphatic nodules in ileum
contains macrophages
Tonsils
create a ring of lymph tissue around pharynx
gather and remove pathogens entering pharynx
Adenoid Tonsil
in posterior wall of nasopharynx
Palatine Tonsils
in posterior region of oral cavity
Lingual Tonsils
at base of tongue
Appendix
has large groups of lymphatic nodules
