what are the major componemts of the lymphatic system?
what is lymph ?
where is it found
its an extracellur fluid(ECF) similar to plasma.
found in body tissues(intersistial fluid)
what are lymphatic vessels?
networkof vessels that carry lymph throughout the body andcarry lymph and eventually to the venus blood stream.
wha is lymphatic tissue?
protective tissue that is scattered throughout the body,it is a specialized connective tissue conataining large numbers of lymphocytes
what systems combined are called the circulatory system?
and what do they circulate?
the lymphatic and cardiovascular systems.
tthe lymphatic circulates lymph the cacrdiovascular circulates blood
what are the lymphatic organs?
spleen and thymus
what are the major functions of the lymphatic system?
fluid balance:excess intersistil fluid from tissue spaces isreturned to the blood by lymphatic capillaries ;once it enters a lymphaic capillary it is called lymph
distribution:of hormones nutrients and waste products from site of orgin to general circulation.
defense:microorganisms and antigens are destoyed by WBC's
everyday about how much fluid leaves your blood capillaries and enter the interstital fluid of the bodys tissues?
how much of that is reabsorbed back into the blood capillaries?
how much of the remaning moves to the lymphatic cappillaries so that they are removed from the tissue?
the lymphatic system absorbs ______ from the ________,and________carry the ____ to the ________.
what vitamins are transported from the GI tract to the blood?
lipid soluble vitamins A,D,E,K
where are lymphatic capillaries found?
in most tissues of the body
how are lymphatic capillaries diffrent from blood capillaries?
they oringinate as blind pocket; each lymphatic capillaryhas one closed end; ECF enters it through a flap like minivalve.
they are larger in diameter thn blood capillary.
they have thinner walls
there are gaps between the endothelial cells that comprimise the lymph. capillary wall making it more porous; fuids can enter it but cant leave
lypmhatic vessels structure?
resemble veins in structure. from the capillaries lymph oves into lymphatic vessels;they contai valves which keep the lymph moving in one direction through these low pressure vessels.
in general tissue will contain many more _______ than ______but they will be much smaller.
lymph moves in response to?
1. contraction of surrounding skeletal muscles. like veins lymph vesslers have to keep fluid moving in one direction.
2. contraction of smooth muscle i the wall of the lymphatic vessel.
3.pressure change in the thoracic cavity during respiration.
what is the thoracic duct?
the largest lymph vessel, drains into the left subclavian vein. drains the entire body except the upper right quarter.
wha is th cysterna chyli?
expaned abdominal portion of the throacic duct; this is where fat filled vesselsfromthe digestive tract enter the lymphatic system
wat is the right lymphatic duct?
drains lymph fromthe upper right quartre of the body; drains into the right subclavin vein
what are Tcells
atack foreign cells or body cells infected by viruses, they mature and divide in the thymus. they are responsible for cell mediated immunity mening that the protection is directly from living cells.
what are b cells
responsilbe fo anitibody mediated immunity (=humoral immunity); a percentage ogf B cells mature in toplasma cells which produce and secrete anitboties which destry antigens
what are NK cells (natural killer cells)
attack foriegn cells and cells infected with viruses and cancer cells.
what are lymphoid nodules?
and their properties?
they are lymphocytes densly acked into a area of areolar tissue
1.occur in the connective tissue deep into the epithelia that line the respiratory, digestive ,and urinary tracts.
2. have a centeral zone called a germinal layer which contains dividing lymphocytes
3.boundaries of the nodule are not distinct because they have no fibrious capsule surrounding them.
what are lymph nodes?
what are there functions?
where are they found?
1.they are smalloval organs along the lymphatic vessles,each is covered by a capsule of dense fibrious tissue connective tissue;trabecule extend inward to divide the node into compartments.
2.they filter the lymoh ,removing bacteria an antigens
3. they are found throughout the body. superficial aggregations are foun in the inguinal, axillary, and cervical regions
what are affrent lymphatic vessels?
vessels that carry lymph to the lymph node.
as lymph flows through the ________ it is exposed to __and __cells and _____; at least ____% of ;pathogens are removed
what are efferet vessels?
vessels that carry ymph away from the lymph node
where isthe spleen located ? and what are its functions?
1. located in the superior,posterior,left abdominal cavity
it contains the largest amount of lymphoid tissue in the body.
2.it filters the blood and is involved with the removal of abnormal blood cells and other blood components by phagocytosis, storage of iron from recycled RBC's, initiation of immune response by B and t cells in response to antigens in circulating blood. its also acts a s a blood reservior.
what is red pulp?
1. area of the spleen thats contains large numbers of RBC's
2.consists of reticualar fibers,its rich in macrophages
3.mainly concerend with disposing of worn out RBC's and bloodbourne pathogens
what is white pulp?
1. area of the spleen that resembles lymphoid nodules.
2 composed of lymphocytes suspended on reticula fibers
3. involved with the immune functions of the spleen
what does bone marrow contain?
contains lymphoid stem cells that can form all types of lymphocytes: it produces b cells, pre T cells which travel to the tymus where they mature.
where is the thymus located ?
what are its functions?
1. located in the medistinum just posterior to the sternum and anterior to the heart
2.under the influence of its hormones thymopoietin and thymsins, the pre Tcells divide producing various kinds of Tcells
3.after maturing in the thymus they enter the blood to travel to various lymphoid tissue
what are tonsils?
large lymphoid nodules in the walls of the pharynx and oral cavity
also called the adenoids, located in the posterior superior wall of the nasopharynx
located at the posterior margin of the oral cavity along the borderof with the oropharynx
located under the attached base of the tongue
what are Peyer's Patches?
1. clusters of lymphoid nodules deep to the epithelial lining of the small intestines
2. contain lymphocytes and macrophages which remove micororganisms debris and antigens from the digestive tract.
what are the 2 major functions of the immune system?
1. destroy pathogens
2. detect and kill abnormal cells, such as cancerous cells
how are pathogens classified?
what are the 5 types ofpathogens and whre they are produced?
1. classified by size and where theyare located in the body.
2. parasitic worms (macro cellular)
protozoa " "
bacteria " "
what are the innate defenses?
1. innate exteral defenses: are surface barriers like skin and mucous membranes; if these are penetrated the next line of defense is
2. innate internal defenses: these include cells and chemicals in the body fluids, fever and inflammation.;they identify enemies by recognizing markers that are unique to pathogens. when overwhelmed they secrete chemical messengers to mobilize adaptive defenses.
how do adaptive defense differ from thye are innate defenses?
1. thye are specific directed against identifiable enemy
2.they involve B and T lymphocytes
3.they have memory they will recognize an enemy if it attacks again in the future
they are systemic they can act anywhere in the body
how do B and T lymphocytes recognize pathogens?
by binding to them they recognize them by shape alo known as the antigenic determinant.
what is humoral or antibody mediated immunity?
immunity that is directed against pathogens in ECF it involves B cells and antibodies
what is cellular or cell mediated immunity?
directed against pathogns within the cell it involves T cells
charateristics of skin that help it to resist invasion?
1.it is water resistant and though keratin outer layer
2.intercellular layer hold skin tightly together
3.skin secretions are scdic and have chemicals that make it inhospitable to pathogens. e.g. lysozyme destroys cell walls of cetain bacteria
what re the 5 components of the internal defense system?
1. neutrophils: first cell to leave the blood and enter tissues at the site of infecion or trauma. are short lived
2.monocyte: follow the neuts. to the affected area once there they transform into macrophages they phagocytize more than neutrophils.
3.they use special receptors to recognize and bind to molecules on pathogens but not on normal cells. it ingests the cell then sends a chemical alarm that signals that mobilizes other cells.
1. lymphocyte involved in innate immunity
2.attack body cells that have been invaded by pathogens or cancer; will also attack cells of transplanted tissues
3. they are larger than B and T cells and do not have receptors.
4.they are involved with T cells in immune surveillance: continually scan our cells for abnormalities.
antimicrobial proteins: interferons?
interfere with viral replication and activate immune cells; cells that have been attacked by a virus release interferon to help protect neighboring cells that have not ben affected.
antimicrobial protein: complement?
it inhances other components of both innate ans adaptive defenses; it can mark cells fro phagocytosis it promotes inflammation and kills some bacteria
what is the purpose of inflammation?
the prrpose is to bring WBC's and plasma proteins to the injured site:inflammatory mediators cause vasodilation and an increase in vascualr permability/
what is he purpose of fever?
higher body temp. enhance phagocytosis and cause the liver spleen to sequester ironand zinc. pathogens also dont grow well at a high temp.
what are pyrogns?
chemicals secrted by leukocytes and machophages that have been exposed to foregin substances in the body; they caus the body's thermostat in the hypothalmus to set the temp. higher
education of lymphocytes:
1. the lymphocyte is abel to recognize its one specific antigen by binding to it.
2. the lymphocyte is unresponsive to self antigens so it does not attack the body's own self
3.T cells become immunocomptetent ans self tolerent in teh thymus. and for bcells this occurs in the bone marrow
what re auto immune diseases?
lymphocytes attack he body's own cells.
type 1 diabetes, Graves disease, And MS
what are memory cells?
are created in large numbers during primary immune response(exposed to antigen for the first time) they create a large number of effector cells during a a secondary immune response(exposed to a antigen again) thus the response to the secosn attack will be much greter.