Lymphatic System

is the lymphatic system its own system

not really - it is part of the immune system

what is the lymphatic system

a circulatory system that runs alongside the blood circulatory system

purpose of the lymphatic system

aids the immune system by returning excess fluid (from tissues) to the blood and fighting pathogens

structures of the lymphatic system

lymphatic vessels

lymph

lymph nodes

lymphatic vessels

vessels of the lymphatic system, intertwined with capillaries

have endothelial flaps

endothelial flaps

loose, overlapping cell junctions that act as one-way mini-valves

open when outside tissue pressure rises to let fluid in, and they shut when inside pressure rises to stop fluid from leaking back out

lymph

the extracellular fluid of lymphatic vessels

lymph nodes

bean-shaped organs that aid in filtration and immune cell production and storage

primary organs of the lymphatic system

bone marrow (red)

thymus

bone marrow (red)

creates the stem cells needed for immune responses

almost all immune cells mature here (except T cells)

thymus

a bi-lobed gland that facilitates the development of T cells - where they mature

secondary organs of the lymphatic system

lymph nodes

spleen

lymphoid nodules

lymph node purpose

remove debris and pathogens

teach T and B cells

house certain immune cells

spleen

filters the blood for pathogens and recycles old/damaged RBCs

lymphoid nodules

dense areas of immune cells that trap pathogens and facilitate adaptive immune response

tonsils

bronchus-associated lymphoid tissue (BALT)

mucosa-associated lymphoid tissue (MALT)