Lymphatic System and Immunity Flashcards
in the lymphatic system, what are the vessels called?
lymphatic vessels
what is the fluid called that circulates the lymphatic vessels?
lymph
state some functions of the lymphatic system
drains excess interstitial fluid,
transports dietary lipids
carries out immune response
what are the two primary lymphatic organs?
red bone marrow and thymus
what are the secondary lymphatic organs?
lymph nodes, the spleen and lymphatic nodules
how many lymph nodes are found are the body?
around 600
where can lymph nodes often be found?
near mammary glands, the axilla and groin
what are the two types of immunity?
innate immuntiy (1st and 2nd line of defence) adaptive (acquired) immunity
explain innate immunity
provided by the external physical and chemical barriers offered by the skin and mucous membranes, including: epidermis, cilia, saliva
name the innate immunity internal defences
antimicrobial substances (substances which discourage bacteria growth), natural killer cells and phagocytes, inflammation and fever
name the cells of the immune system
neutrophils, eosinophils, basophils, monocytes
t-cells, b-cells, natural killer cells, macrophages
explain what natural killer cells are and what they do?
5-10% of lymphocytes are NK cells.
They kill tumour cells and any cells that display abnormalities
explain what phagocytes are and what they do?
specialised cells that perform phagocytosis (cell-eating)
explain what macrophages and neutrophils are?
two types of phagocytes
explain phagocytosis
the pathogen interacts with the phagocyte receptors (binds with them)
the phagocyte engulfs the pathogen
this forms a phagosome
the phagosome forms with lysosome to make phagolysosome
enzymes digest the ingested pathogen
the phagocyte discards the waste materials
explain adaptive (acquired) immunity
offers a defence to specific to organism and foreign materials (‘non-self’)
provides a memory for most previously encountered antigens
involves lymphocytes called b-cells and t-cells
what stops the lymph from going backwards in the lymphatic vessels?
valves
what helps the movement of lymph in the lymphatic vessels?
smooth muscle contracts, skeletal muscles
where are b-cells produced?
in the bone marrow
where are t-cells matured?
thymus
when do B-cells respond?
when pathogens are outside of the cell
when do t-cells respond?
they respond in the cell-mediated response when the pathogens are inside of the cell
