LYMPHATIC Flashcards
What 5 things encompass the lymphatic system and explain each of them
FLUID - Lymph - protein rich
VESSELS - Lymphatics run close the A&Vs run superficial to deep
CELLS - 1) Lymphocytes (B, T and NK cells) 2) Supporting cells (Follicular dendritic cells, macrophages)
TISSUES - 1) Diffuse lymphatic tissue in mucosal, gut and bronchial areas 2) Lymphatic Nodules: Tonsils (x3), Peyers patches (intestine), Vermiform appendix
ORGANS - Lymph nodes, thymus, spleen
How much lymph is drained per day?
3L
What is the lymphatic system?
A network of vessels that carry lymph drained from tissue - role in immunity
What basic roles do B and T cells have, what kind of cell are they?
Both lymphocytes - type of leukocyte (WBC)
B cells - produce antibodies, seek out antigens
T cells - Different types but ‘destroy’ antigens.
What is innate vs adaptive immunity? What two kinds of adaptive immunity are there? Which cells initiate all of these?
Innate: (initial response to antigen): Inflammation response = Macrophages and neutrophils, and also NK cells.
Adaptive:
1) Humoral (e.g. Blood) - Antibody production mediated by B cells that transform into plasma cells and work ‘outside of cell’
2) Cell mediated - cytotoxic T tell mediated
Which two major cells initiate the immune response vs the two that initiate the inflammation response?
IMMUNE: T cells and macrophages initiate as B cells need to be activated
INFLAMMATION: Macrophages and neutrophils
How is lymph made?
Lymph is a protein rich fluid that leaves capillaries - to interstitium and into lymphatics before venules
Are B and T cells present in both blood and lymph?
Yes - until activated then do their job
How do lymph nodes work?
Filters, traps antigen, processes antigen, presents it to T cells/NK cells for destruction.
Lymphatic system carries the white blood cells and antigens to lymph nodes where they are processed
What are the roles of the spleen (3)? Explain them.
Like lymph nodes filter lymph, it filters blood. It also filters old/faulty erythrocytes and platelets. Thirdly is rescues iron from Hb.
Immune response: 1) Antigen presentation by APCs 2) Activation and prolif of B and T cells - production of antibodies 3) Removal of macromolecular substance from blood - macrophages.
What’s the role of the thymus? Why would you do a thymectomy?
Thymus is responsible for maturing T cells that have come from bone marrow. Once puberty hits the thymus involutes and turns mostly to fat. You may do a thymectomy in someone with myasthenia gravis as up to 20% of these pts can get Thymomas (cancer).
What three organs are involved in the lymphatic system?
Lymph nodes
Spleen
Thymus
What are Peyers Patches? What are their function?
Lymphoid tissue in gut, immune response in GI with incoming pathogens via food.
Is there any lymph tissue in CNS?
No
How does lymph flow through lymph node?
Afferent to Efferent through medulla
Name 3 professional antigen presenting cells that will present an antigen to a T cell
Macrophages
B cells
Dendritic cells
What are three roles of B cells
Seek antigens
Make antibodies
Present antigens to T cells to destroy
Where are follicular dendritic cells located? What are two roles?
In germinal centres of lymph nodes
1) Hold antigen/antibody complexes for months
2) Cause prolif of B cells espesh memory B cells
What is the immune role of the spleen? Which 3 cell types mediate this?
Immune role of spleen is it contains APCs that can remove pathogens from blood. Using normal immune response - B cells T cells macrophages.
What is the haemopoietic function of the spleen (2)?
1) Removal of old/damage/abnormal RBCs
2) Retrieval of iron from Hb
What is lymphatic tissue split into and where can it be found? Think diffuse vs nodules (3 of each)
Diffuse: MALT GALT BALT
Mucosal, gut, bronchial
Nodules: Tonsils, Peyers Patches, appendix
Do lymphocytes (B/T cells) enter lymph nodes via lymph or blood mostly? Do they leave via lymph or veins?
Normally through feeding artery (a few in lymph). Mostly leave via lymph vessel.
What lymphadenopathy? What causes it?
Enlarged lymph nodes due to infection. Increased numbers of lymphocytes causes the swelling.
How do cancers metastasise to lymph nodes?
Via afferent lymphatics
Can the body function if spleen is surgically removed? How? How does this increase risk of DVT?
Yes liver and bone marrow take over role of spleen. However increased number of platelets increases the risk of DVT as increases the risk of thrombus forming. Spleen normally breaks up platelets.
Are NK cells involved in both innate and adaptive immunity?
Yes
Which type of collagen is found in lymphatic tissue?
III
Which 3 things aid flow of lymph round lymph vessels back to venous system?
-ve Pressure in thorax
Arteries nearby
Skeletal muscle contraction
