The Lymphatic System
,The Lymphatic System
Overview
The lymphatic system is a system of specialized
vessels and organs whose main function is to return
the lymph from the tissues back into the
bloodstream (specifically the venous system).
It is considered as a part of both the immune
system and circulatory systems.
Functions
• Immunity against foreign pathogens
• Fluid balance: removes excess fluids
• Helps the intestine absorb fats
,The Lymphatic System
Key facts about the lymphatic system
Definition The lymphatic system is a network of vessels and
organs that regulates the amount of fluid in the
human body and defends it against infections.
Structure Lymphatic capillaries; lymphatic vessels, ducts and
tracts; primary and secondary lymphoid organs,
Function Fluid regulation; immune surveillance; transport of
large molecules
Clinical Cancer spreading
relations
, Lymphocytes
• A lymphocyte is a type of white blood cell that is
part of the immune system.
• Lymphocytes make up roughly 20-40 % of the
total number of white blood cells.
• Found in the circulation
• Concentrated in central lymphoid organs and
tissues, such as the spleen, tonsils, and lymph
nodes, where the initial immune response is likely
to occur.
• 3 types: T cells, B cells and Natural Killer Cells.
, Lymphocytes
2 main types:
• T Cells (thymus cells)
• B cells (bone cells)
B cells:
• Originate in the bone marrow
• Produce antibBodies
• Attack invading bacteria, viruses, and toxins.
T cells:
• Originate in bone marrow
• Migrate and mature in the thymus
• T cells destroy the body's own cells (cytotoxic) that
have been taken over by viruses or become cancerous.