Ch.20 areas to work on Flashcards
Where are lymphatic capillaries absent from?
Bones, teeth, bone marrow, and CNS
Because lymphatic capillaries are able to take up larger molecules that blood caps couldn’t, this acts as a route for pathogens and cancer cells to enter the lymphatic system. Does this make sense?
Yes, because lymphatic vessels are more permeable than veins or arteries.
Specialized lymph capillaries present in the intestinal mucosa. Does this describe lacteals or the cisterna chyle?
Lacteals
What do lacteals do?
Absorb digested fat and deliver chyle to the blood
Veins have thinner walls than arteries. ______ vessels have thinner walls than even veins
Lymphatic
Do lymphatic vessels anastomose more frequently than veins?
Yes
Do collecting vessels in the skin travel with deep veins?
No, they travel with superficial veins
What did the thoracic duct start out as in about half of individuals
A sac called the cisterna chyli
Is lymphangitis a condition in which Lymphatic vessels appear as red lines under the skin? If so, what causes it?
Yes. It is caused by inflammation of larger lymphatic vessels that contain vaso vasora
Lymphocytes are lymphoid cells of the innate immune system. True or False?
False, they are of the adaptive system.
What do antibodies do?
They mark antigens for destruction. (phagocytes then come and eat them up)
B cells produce _____ cells, which secrete antibodies
Plasma
What do dendritic cells do?
They capture antigens and deliver them to the lymph nodes
Do macrophages phagocytize foreign substances?
Yes
Do reticular cells produce reticular fibers called lacteals in the lymphoid organs?
No, it is called stroma. (lacteals are in the GI tract)
How does lymphoid tissue support lymphocytes?
The tissue allows for lymphocyte proliferation and also houses them until they need to be activated. They can be stationed there or float around as they filter through the lymph looking for antigens.
Where can you find germinal centers of proliferating b cells?
In lymphoid follicles (nodules)
Can lymphoid follicles form part of larger lymphoid organs?
Yes
Are peyers patches and the appendix areas of isolated aggregations of lymphoid follicles?
Yes
Are the two primary lymphoid organs the red bone marrow and thymus?
Yes
What characterizes secondary lymphoid organs?
A secondary lymphoid organ is where mature lymphocytes ( B and T) first encounter an antigen and become activated
Why are the red bone marrow and thymus not secondary lymphoid organs?
Because T and B cells originate in the R bone marrow (b cells mature in RBW and T cells in thymus) and they are then seeded into 2ndary lymphoid organs
Is MALT a secondary lymphoid organ?
Yes
Are lymph nodes secondary lymphoid organs?
Yes
How do lymph nodes cleanse lymph?
Macrophages within the nodes remove and destroy microorganisms
How are lymph nodes related to the immune system location wise?
Lymph nodes offer a place for lymphocytes to become activated and then begin attacking antigens (remember, lymphatic capillaries are extremely permeable and allow larger molecules like pathogens and cancer cells to enter the lymph stream)
Remember that lymph nodes are small and mostly bean shaped. What’s the cm?
~2.5
Are lymph nodes surround by a trabeculae capsule?
No, surrounded by an external fibrous capsule
The fibrous capsule extends inward as traveculae that divides the node into compartments. T or F?
True
Do efferent lymphatic vessels take fluid away from the lymph node?
Yes
Do afferent lymphatic vessels take fluid away from the lymph node?
No, they bring it to the lymph node
How does the lymph node structure ensure the lymph gets cleansed properly?
There are more afferent vessels than efferent, which means lymph gets backed up in the lymph node and has to go through several sinuses before reaching the efferent vessels. This also gives the housed macrophages and lymphocytes time to employ their defensive functions
What are inflamed, swollen and tender lymph nodes called?
Buboes
What is the largest lymphoid organ?
Spleen
The splenic artery and vein are at the spleen’s _______
hilum
In which lymphoid organ do lymphocytes proliferate?
Spleen
Does the spleen store breakdown products of RBC’s for later reuse?
Yes
Does the spleen store plasma and lymphocytes for release into the blood when needed?
No, it stores platelets and monocytes (which become macrophages)
Which lymphoid organ has red and white pulp?
Spleen
Do you find lymphocytes on reticular fibers in the red or white pulp of the spleen?
White pulp
In the spleen, _____ pulp clusters are found around central arteries; they appear as islands of _____ in a sea of ____ pulp.
White pulp clusters are found; looks like islands of white in a sea of red
Does the spleen have a thick or thin capsule?
Thin
Splenectomy’s are old school. Why?
Removed to prevent hemorrhaging and shock. Eventually it was discovered the spleen can often enough repair itself
Which two organs take over its functions if the spleen is removed?
Liver and bone marrow
At what age can a spleen regenerate itself?
12 and younger
What does MALT stand for and what does it do?
Mucosa-associated lymphoid tissue. Protects pathogens trying to enter body.
Where is MALT found?
Respiratory tract, genitourinary organs, and digestive tract (anywhere your body is exposed to outside pathogens)
Is MALT lymphoid tissue found in mucous membranes?
Yes
What three areas is MALT found?
Tonsils, Peyer’s patches, and the appendix
Adenoids are another name for which type of tonsil?
Pharyngeal
Which tonsils are infected the most often?
Palatine (strep throat)
Clusters of lymphoid follicles in the wall of the distal portion of the small intestine are called ______ _____ and generate “memory” lymphocytes
Peyer’s patches
Like peyer’s patches, the ______ also generates “memory” lymphocytes
Appendix
Which organ is bilobed and partially overlies heart?
Thymus
Which organ stops growing during adolescence and then gradually atrophies?
Thymus
How is the stroma different in the thymus?
It is made up of epithelial cells, not reticular fibers
The thymus has no follicles because it lacks this lymphocyte.
B cells
What does the blood thymus barrier prevent?
It prevents immature T cells from seeing any antigens and activating prematurely
Where to T cells become immunocompetent?
Thymus
