1. Immune System
BIG IDEA: Your body uses fluid, organs, cells and molecules to defend you against disease.

2. 1. How is the flow of lymph through the body different from the flow of blood?

3. Lymph is carried with blood to the tissues
Lymph enters lymphatic capillaries which are different from blood capillaries.
These lymph capillaries move lymph to successively larger vessels called lymphatic venules
It is carried to lymph nodes
Which empty into lymphatic veins
Which empty into one of two terminal vessels
Right lymphtic duct
Thoracic duct
Which then empties into the heart
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5. What happens in the lymph nodes?
Lymph nodes filter out ‘bad’ stuff
Lymph nodes have phagocytic cells that destroy bacteria or abnormal cells
Lymph enters a node and is ‘percolated’ through the sinus area
Lymph enters through the afferent vessel
Lymph exits the node through the efferent vessel
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6. Lymph Nodes
Lymph Node magnified
Lymph Nodes of the Body
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7. Lymph Node Structure
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8. Understanding Define lymph
How is a lymph capillary different/same from a blood capillary?
What are the names of the 2 large ducts that all lymph empties into?
What prevents lymph from flowing backwards?
What is the primary function of lymph?
What happens in a lymph node?
Where are lymph nodes located?
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9. What other organs are part of the immune system?
Thymus
Spleen
Tonsils
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10. How does the body defend against infection?
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12. If individual A and B had been exposed to a disease in their youth (which means they came down with the symptoms and survived), what type of immunity do they have as adults? A B E F C D G
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13. Would they pass that immunity to their children?B E F C D G
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14. If individual F had a measles vaccination, what type of immunity does she have now?B E F C D G
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15. If baby G is still nursing from his mother, would he have an immunity to measles? If so, what type? If not, can anything be done? A B E F C D G
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16. The cells and molecules of the immune system
Lymphocytes
T cells
B cells --- antibodies
Complement proteins
Phagocytes
Macrophages
Neutrophiles
Natural Killer Cells
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17. Oversimplified: How do these cells work together to provide immunity against disease?
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18. Vocabulary Cytokines—molecules that signal immune cells to respond
Class II MHC molecules (major histocompatibility complex)—make us unique “self”
Antigen—foreign material
Phagocytosis—engulfing
Antigen processing—breaking the antigen into fragments
IgM receptors—specific protein involved in making antibodies
Memory cells—B cells that “remember” this specific antigen
Plasma cells—B cells that create antibodies
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19. So how do these cells provide immunity from diseases?
Humoral immune response
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20. Understanding Foreign invader Macrophage “bumps” into it
Macrophage alerts T helper cells
T helper cells alert B cells
B cells
Manufacture antibodies
“Remember” this invader in case it invades again
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21. Does the immune system ever “get it wrong”?
YES!!
Allergies—inappropriate response to harmless environmental antigens
Autoimmunity—inappropriate and excessive response to ‘self’ antigens
Isoimmunity—excessive reaction to antigens from a different individual of the same species
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