lymphatic system Flashcards
what is lymph
a thin fluid that resembles plasma and has lower amounts of protein.
what is chyle
a special type of lymph that arises from the GI tract and is white and cloudy because it contains fats and lipids
name the lymphatic vessels
lymphatic capillaries, lymphatic ducts, lymphatic trunks and lymphatic veins.
where are lymphatic vessels found
they lie adjacent to cardiovascular vessels and are arranged superficially and deeply. they pass through muscles where contractions aids the flow. ducts and trunks may contains smooth muscle to aid flow swell because these are the larger vessels
where does the lymph flow from and to
enters the lymphatic system from the tissue fluid into the capillary then goes to vessel node trunk and duct and then rejoins back to the vein
lymphatic vessels vs veins
both have low pressure, valves present and a small amount of smooth muscle. lymph system has lymphangion which is compression by local arteries and veins to propel lymph
where do ducts and trunks drain into
upper right quadrant drains into right subclavian vein, rest of body drains into left subclavian vein
examples of lymph nodes
neck, groin and armpit
what are lymph nodes
shaped like kidneys they filter the lymph. enters through efferent vessel and a efferent vessel that leaves via concave hilum. also has feeding artery and draining vein that also leave via hilum. contains multiple follicles with immune cells (dendritic cells). main tissue is reticulin
what are dendritic cells
antigen antibody complexes adhere to them and they then cause proliferation of B cells. B and T cells work together to produce an inflammatory response
difference between T and B lymphocytes in the lymphatic system
B (attack outside cells) recognise antigen whereas T (attack inside cells) need to have them presented to them. Lymphocytes mostly enter the lymphatic system vie artery
why do you get enlarged lymph nodes
as lymph nodes fight infection the germinal centres fill with lymphocytes causing the lymph nodes to swell causing pain. cancer and lymphoma can also cause lymph nodes to swell
list the lymphatic organs
thymus, spleen, tonsils, appendix and payers patches
the thymus structure and function
similar to lymph node structurally and its function is mature bone marrow stem cells into T cells
spleen structure and function
similar structure to lymph node but operated into white and red pulp. it filters blood, has an immune function with B and T cells and APC and it removes old/damaged erythrocytes ad removes the iron from them. erythrocytes are also stored here
spleen surgery for ruptured spleen
splenectomy will remove the spleen and the bone marrow takes over the removal and destruction of old red blood cells. However it also increases the risk of infection
what is a splenomegaly
an enlargement of the spleen in response to infection. Can grow to 10 times the size
the tonsils structure and function
prevent pathogen ingress through oral and nasa routes and the nodules reside in crypts which increase the surface area
what causes swollen tonsils
the surface of the epithelia have microfilm cells which present antigens to immune cells and they will swell when B and T cells begin to profliliate
structure and function of the appendix
nodules reside in crypts to increase surface area and they have many microfold cells. They prevent pathogen ingress through GI routes and from ileum
payers patches structure and function
nodules reside in surface domes and have many microfold cells. They are found on the side of the ileum and prevent pathogen ingress through digestion
functions of the lymphatic system
fluid balance(interstitial fluid excess) transport of fats and soluble vitamins from digestive system into circulation defence against invading pathogens storage and destruction of old erythrocytes
sentinel lymph nodes in cancer detection
during metastatic disease cancer cells will travel by angiogenesis and if the cancer is in the breast they will travel to the axilla node and this will swell. Probe this area and if cancer cells present then mastectomy must be performed
what is lymphodoema
collection of fluid in the interstitial space due to the lymph system not draining the interstitial fluid properly. This may happen after surgery when a lymph node may have accidnetally been damaged or been removed on purpose if it was metastatic for example
