Sesh 4: Lymphatics, Immunity And Blood Flashcards
How much interstitial fluid does the lymphatic system collect per day?
3 L
What pressure does the lymphatic system operate under?
Low pressure.
What is the movement of lymph mainly due to?
Movement of skeletal muscle that the lymph flows deep to.
In larger lymphatics due to smooth muscle in walls of vessels.
Are there lymphatics in the CNS?
No
What are the 3 types of lymphatic nodules?
- Tonsils (pharnygeal, palatine and lingual)
- Peyer’s patches (duodenum)
- Vermiform appendix
What are the 4 broad locations of lymph nodes?
- Cervical
- Axillary
- Lumbar
- Inguinal
What is the direction of lymph flow in a lymph node?
Afferent vessel enters via convex surface to germinal centre to medulla to efferent vessel- out via hilum
What do follicular dendritic cells in the germinal centres of lymph nodes do?
Supporting cells.
Antigen-antibody complexes attach to their dendritic processes, causing proliferation of memory B cells.
What kind of reaction is the initial immune response to a foreign antigen, and what cells are involved?
Inflammatory.
Macrophages and neutrophils.
What cells produce antibodies?
Plasma cells (B cells that secrete specific antibodies).
What is lymphadenopathy?
Enlarged lymph nodes.
What is the largest lymphatic organ?
The spleen
What is the main general function of the spleen?
Filters blood.
Why is it very serious if the spleen ruptures?
It has a very rich blood supply, so could exsanguinate.
If the spleen in removed (splenectomy), which organs can take over the removal and destruction of ageing/abnormal red blood cells?
Liver and bone marrow.
What 3 things does splenectomy increase the risk of?
- Infection by encapsulated bacteria
- DVT
- Pulmonary embolism
What often happens to the thymus in myasthenia gravis?
Becomes enlarged or thymoma forms
What is the role of the thymus?
Maturation of bone-barrow derived stem cells into immunocompetent T cells= thymic cell education.
What are the 2 types of specific immune response?
- Humoral-pathogens outside cells
- Cell-mediated- pathogens inside cells
*both are integrated
What type of lymphocytes initiate both the humoral and cell-mediated immune response?
T helper cells
Phagocytosis is part of the __________ immune response.
Non-specific
What 3 types of cells are phagocytes?
- Macrophages
- Neutrophils
- Dendritic cells
What are the 2 pathways of complement cascade activation?
- Classical- C1 activated when binds antigen-antibody complex
- Alternative- C3b activated when reacts with antigens
What 3 things can complement lead to?
- Inflammation
- Opsonisation for phagocytosis
- Membrane attach complex- cell lysis
