lymphatic system Flashcards
Lymphatic system
organ system that is part of immune system and complementary to the circulatory system
lymph
-fluid leaked from blood vessels, bathes the tissue and goes back to the blood stream
-colorless(lacks RBC) fluid contenting WBC
lymphatic vessels and capillaries
-thin-walled vessels
-endothelia cells and smooth muscle
interstital fluid
-fluid around the cells
-flow into lymphatic capillaries, following pressure gradient
bone marrow produces?
-lymphacytes(immature T cells, B cells, NK cells)
Thymus?
-responsible for maturation of T cells
Lymph nodes?
-Bean shaped structures along lymph vessels
-filter substances that travel through lymphatic fluid
spleen?
-Synthesis and maturation of lymphocytes(B and T cells)
-filter blood
-stores blood cells
-stores platelets
-recycles iron
-destroys old blood cells
tonsils?
-protection of pharynx against pathogens
Appendix
-protection of the large intestine
Mucosa
associated lymphatic tissues (MALT) in digestive, respiratory, unitary, reproductive tracts
lymphocytes
-T cells(most common)
-B cells
-natural killer (NK) cells
-synthesized in bone marrow,
T cells
-Killler T cells (thymus derived cells)
-attack and destroy foreign cells or body cells infected
-direct cellular attack
NK cells
-attack foreign cells or body cells infected
-secrete chemicals that lyse the plasma membrane of the abnormal cells
-more rapid response
B cells
-activated by Helper T cells
-differentiate into plasma cells or memory B cells
-plasma cells secrete antibodies, leads to destruction of pathogens
-memory B cells remember the antigen
helper T cells
-stimulate the responses of both T and B cells
-no helper T cells to stimulate B cells then no antibodies
-no helper T cells to stimulate T cells then no active T cells to kill pathogens
Regulatory T Cells
- moderate the immune response
-wind down immune response by deactivating B and T cells
Memory T cells
-respond to antigens they have already encountered by cloning
-reserve population of T cells that can respond explosively to a subsequent exposure to their antigen
Macrophage
-large, active phagocytes
-present everywhere in body
-WBC that can engulf a pathogen, destroy target by releasing toxic chem into interstitial fluid, bind to pathogen in interstitial and destroy it
Primary response
-1st exposure to antigen
-few B cells activated
-antibody level increases over a period of 10 days
Secondary response
-exposure to the same antigen
-memory B and T cells are respond aggressively
-produce lots of antibodies faster
Innate immunity
-non specific
-born with it
-skin, phagocytes
Naturally acquired innate immunity
-baby receives antibodies from mother
Artificially acquired innate immunity
-person receives antibodies to fight infection
