Download Our Body`s Defense

The Lymphatic System
• Helps fight infection
• Plays an important role in the body’s
immunity to disease
• Supports the cardiovascular system
What does it do?
• Maintains the body’s fluid balance
– Carries excess fluid away from body tissues
– Assists the body in its defense against pathogens
Structure of
• Lymph
• Lymphocytes
Our Body’s Defense
The Lymphatic System
Lymph
• Clear yellow fluid that fills the areas around
the body cells
Lymphocytes
• Specialized white blood cells that provide the
body with immunity and protects the body
against pathogens
– B-Cells
– T-Cells
B-Cells
• Lymphocytes that are stimulated to multiply
when they come in contact with a pathogen
• Produce antibodies that attack the pathogen
• Produce memory cells that create immunity
T-Cells
• Lymphocytes that are stimulated to enlarge and
multiply when they encounter a pathogen
• Killer cells-stop the spread of disease
• Helper cells-aide in the activation of B-cells and Killer
T-cells and control the body’s immune system
Other important terms:
• Pathogen
– An organism that causes disease
• Lymphatic Vessels
– Carry lymph to lymph ducts in the neck and chest
Terms:
• Lymph Nodes
– Masses of tissue which serve to filter lymph
before it returns to the blood
• Spleen
– Organ that keeps the body free of foreign
substances and stores B-Cells
Terms
• Tonsils
– Mass of lymphatic tissue that filters out pathogens
that enter the mouth and nose
• Thymus Gland
– Produces lymphocytes in infants and children