Flashcards in Blood and Lymph 2 Deck (18):
monocytes: what? arrive when? do what?
highly mobile phagocytic cells. arrive at site shortly after neutrophils. release chemicals to attract other phagocytes, and fibroblasts (to make collagenous scar tissue)
lymphocytes: what type of immunity? 3 cell types
specific aka adaptive: will target specific antigens. T cells, B cells and NK cells.
platelets come from? found where?
megakaryocytes in bone marrow. 1/3 in spleen and other vascular organs, otherwise in blood
platelets: are what?
membrane bound enzyme packets that pinch off from cytoplasm of the megakaryocyte
body fluids: two categories?
intracellular (cytoplasm, nucleoplasm). extracellular: blood plasma and interstitial fluid
lymphatic system: 3 roles
produce/maintain/distribute lymphocytes. assist with maintaining normal blood volume. alternate route of transport of hormones, nutrients and metabolic waste
how does lymphatic system help maintain normal blood volume
vascular pressure forces water/solutes across capillary membrane into interstitial fluid, and lymph vessels return that fluid to the vasculature
lymph flow vs. blood flow
blood: actively pumped through vessels by heart. lymph: flows passively along pressure gradient, no pump.
lymphatic vessels: thickness? pressure? backflow?
vessels are very thin: system under super low pressure. lots of valves to prevent backflow
interstitial fluid: called ___when it enters ___? majority of cells are?
called lymph when it enters the lymphatic vessels. 99% cells are lymphocytes. 1% macrophages, eosinophils and neutrophils
lymphocytes: primary aka ___ structures do what? secondary aka __structures do what?
central: produce, maintain and store lymphocytes. peripheral:where most immune responses are initiated
primary central structures for lymphocytes: contain? lymphoid organs include?
contain stem cells to generate B, T and NK cells. bone marrow, thymus gland, spleen
largest lymphoid organ is the? function?
spleen: filters blood (removes abnormal blood cells by phagocytosis). stores iron recycled from metabolized RBCs. initiates immune response by B/T cells
lymph nodes: what? structure?
oval lymphoid organs from 1 - 25 mm in diameter. lots of afferent vessels penetrating a fibrous capsule, and a single efferent vessel exiting
lymph nodes: what do they do? where cells are located?
filter the lymph, remove 99% or more of antigens. T cells in cortex while B cells and macrophages are in the medulla
lymphoid tissue: what? two types?
connective tissues dominated by lymphocytes. can be diffuse, or nodules
diffuse lymphoid tissue: where
mucous membranes of respiratory and urinary tracts