LYMPH 2 Flashcards
whats edema
Swelling caused by excess fluid trapped in body’s tissues (interstitial spaces)
where does edema effect the body
can affect any part of the body but is noticed more in your hands, arms, feet, ankles and legs
what is edema often associated with
any disease that causes salt retention and expansion of the extracellular fluid volume (renal, cardiac, and hepatic disease)
can edema occur without overall salt & water retention? why?
yes, because of microcirculatory alterations affecting Starling forces
what are the four lymphoid cells
lymphocytes, macrophages, dendritic cells, reticular cells
what are lymphocytes
main immune system warriors (T- and B- cells)
» Protect the body against antigens
what are macrophages
Phagocytize foreign substances; Activate T cells
what are dendritic cells
Capture, process, and present antigens to T cells for activation
what are reticular cells
Produce reticular fiber network that supports other cells in lymphoid tissue
what is lymphoid tissue composed of
reticular connective tissue (in thymus)
what cells are constantly entering and leaving the lymphoid tissue
lymphocyes
what does the lymphoid tissue house and provide
an activation/proliferation site for lymphocytes
what does the lymphoid tissue do for immune cells
Gives a good surveillance vantage point
what are the two types of lymphoid tissues
diffuse lymphoid tissues and lymphoid follicles
describe diffuse lymphoid tissue
loose arrangement of cells and fibers in almost all organs
describe lymphoid follicles
solid, spheres of tightly packed lymphoid cells and fibers
what are the two categories of lymphoid organs
primary organs and secondary organs
what happens in primary organs
B and T cells mature; contains red bone marrow and thymus
whats the red bone marrow
origination site for both cells; maturation site for B cells
whats the thymus
maturation site for T cells
what happens at secondary organs
where lymphocytes encounter antigens and are activated
what are some examples of secondary organs
Lymph nodes, spleen, tonsils, Peyer’s patches (small intestine), appendix
what cleanses lymph
only lymph nodes
what are the two basic functions of lymph nodes
cleanse lymph and immune system activation
how do macrophages cleanse lymph
Macrophages remove and destroy microorganisms and harmful debris, so they are not transferred back into the bloodstream/body
how do lymph nodes work to activate the immune system
Strategically located sites where dendritic cells bring back antigens to activate T cells
describe the structure of lymph nodes
bean shaped and less than 1in long; Surrounded by connective tissue capsule that extends inwards; cortex, medulla, lymph sinuses
describe cortex of lymph nodes
superficial, densely packed region
- Contains dividing B cells, dendritic cells, and transient T cells
describe medulla of lymph nodes
inner region containing T and B cells
describe lymph sinuses of lymph nodes
large lymphatic capillaries containing macrophages for lymph filtering
what does the Mucosa-associated lymphatic tissue (MALT) protect
protects passages that are open to the exterior; includes tonsils, appendix, Peyer’s patches
what do tonsils do
remove pathogens that enter through food or air
whats the largest lymph organ in body
spleen
whats the spleen the site for
lymphocyte proliferation
what does the spleen do for blood
filters blood and gets rid of old, defective RBCs and platelets
what does spleen do for RBC products
recycles for future use
what does spleen release
break down products to blood for processing by liver
what does spleen store
some iron from hemoglobin and platelets and monocytes until needed
what are the two sections of the spleen
red pulp and white pulp
what happens at the white pulp
immune function takes pace
what happens at the red pulp
blood filtering takes place
when does thymus function
primarily early in life; atrophy at puberty
what happens at the thymus
T-cells mature
what is the thymus gradually infiltrated with
adipose tissue
what do epithelial cells of the thymus secrete
thymosin and thymopoietin
whats thymosin
stimulates T cell development
whats thymopoietin
indues proliferation of lymphocyte precursors and differentiation into T cells
