Lymphatic systemWhen you turn on a faucet theexcess water runs down the drain.Your body’s excess tissue ﬂuid is removedby the lymphatic system.
Lymphatic systemNutrients, water and oxygen molecules in theblood diffuse through capillary walls to nearbycells.
Lymphatic systemThose substances can become part of the tissueﬂuid that is found between cells.
Lymphatic systemThis ﬂuid is collected and returned to the bloodby the lymphatic system.
Lymphatic systemOnce the ﬂuid is in the lymphaticcapillaries, it is called lymph.
The Lymphatic Systemcarries lymphthrough a network oflymph capillaries andlarger lymph vessels.Then lymph drainsinto large veins nearthe heart.Lymphatic Circulation
There is no pump, likethe heart, in thelymphatic system.The movement oflymph depends on thecontraction of smoothmuscles in the lymphvessels and skeletalmuscles.
Lymph vessels, likeveins, have valves thatkeep lymph fromﬂowing backwards.If the lymphatic systemis not workingproperly, severeswelling occurs becausethe tissue ﬂuid cannotget back to the blood.
Lymph contains water and dissolved substances,but it also contains lymphocytes.Lymphocytes are a type of white bloodcell that help your body defend against disease-causing organisms.
Lymphatic OrgansBefore the lymph enters the blood, it passesthrough lymph nodes, which arebean shaped organs of varying sizes foundthroughout the body.Lymph nodes ﬁlter out microorganisms andforeign material that have been taken up bylymphocytes.
Lymphatic OrgansWhen your body ﬁghts an infection,lymphocytes ﬁll the lymph nodes.The lymph nodes become swollen, warm,reddened, and tender to the touch. After theinvaders are destroyed, the swelling,redness, warmth and tenderness in thelymph nodes goes away.
Lymphatic OrgansAnother important lymphatic organ is thetonsils.They are in the back of your throat andprotect you from harmful microorganismsthat enter through your mouth and nose.
Lymphatic OrgansAnother important lymphatic organ is thethymus.The thymus is a soft mass of tissue locatedbehind the sternum.It makes lymphocytes that travel to otherlymph organs.
Lymphatic OrgansAnother important lymphatic organ is thespleen.This is the largest lymphatic organ.It is located behind the upper-left part of thestomach and ﬁlters the blood by removingworn out and damaged red blood cells.Cells in the spleen take up and destroybacteria and other harmful substances.
Disease of the Lymphatic SystemHIV is a deadly virus.When it enters a person’s body, it attacksand destroys lymphocytes, called helper Tcells that help make antibodies to ﬁghtinfections.This affects the person’s immunity againstcertain diseases.Usually the person dies of one of thosediseases, not from the HIV virus.