What is lymph?
a clear watery liquid that is formed from interstitial (btwn tissues) fluid
What percent of interstitial fluid diffues into capillaries vs lymphatic vessels?
90% to capillaries
10% to the lymphatic vessels
What are lymph “dead ends”
lymph vessels have “dead ends” that gp tp lymph capillaries
What prevents lymph from flowing backwards?
Lymph vessels are lined with overlapping epithelial cells and have internal valves.
Where do lymph vessels carry lymph
to lymph nodes
unlike lymph vessels, lymph nodes are surrounded by what?
a capsule of connective tissue
What forms the structure of the lymph node?
Trabeculae made of reticular fibers
Inside lymph nodes, what are germinal centers?
Germinal centers are areas of rapid mitosis where lymphocytes and macrophages are produced quickly to fight infection
Lymph nodes filter the lymph and send it through what?
an efferent vessel
What are the two ducts in the chest that filtered lymph is eventually delivered to?
-right lymphatic duct
-thoracic duct
these ducts merge with veins where fluid re-enters the circulatory system
What does MALT stand for
mucosa associated lymphoid tissues
Are lymph nodules surrounded by a capsule
No
What do tonsils do
Form a protective ring around the throat to keep foreign invaders from entering the nose and mouth
What do the peyers patches and appendix do
they are groups of lymphocytes near the small intestine that filter bacteria from food and keep beneficial bacteria in the small intestine
What does the thymus do
-it is part of the endocrine and lymphatic system
-it produces thymosin (causes T lymphocytes maturation)
-T lymphocytes come here from bone marrow for thymic education
What does the spleen do
contains 2 types of tissues
-white pulp - filters blood
-red pulp - removes worn-out rbc and is a storage reservoir for blood
What is lymph made of
Water and WBC
What is the function of the lymphatic system
transports, filters, and cleans body fluids of pathogens, toxins and other unwanted substances
What are the extracellular body fluids
-plasma in the bloodstream
-interstitial fluid in tissues
-lymph in lymphatic vessels and nodes
Lymphatic vessels pick up excess ___ fluid, route it through lymph nodes for ___ and return it to the bloodstream
-interstitial
-filtering
Facts about lymph nodes
-100’s throughout body
-vary in size up to 2.5 cm
-filter lymph
-site of lymphocyte production
what is metastasis
occurs when cancer spreads to a new location in the body away from its original site; often occurs through the lymphatic system
What is true and not true about the flow of lymph?
True:
-always moves twrd the heart
-returned to the venous system through ducts
-valves keep it flowing in one direction
false:
-nodes act as pumps to keep fluid moving
what are the 2 types of WBC found in lymph nodes
-macrophages engulf & destroy foreign particles
-lymphocytes monitor fluid for antigens and trigger an immune response
