1. LYMPHATIC SYSTEM
FUNCTION

2. LYMPH Fluid that goes between capillary blood and tissues
Carries digested food, O2, and hormones to cells
Carries wastes back to capillaries for excretion
Since lymphatic system has no pump, skeletal muscle action squeezes lymph along
Lymph in tissues is interstitial fluid

3. LYMPH VESSELS
Transport excess tissue fluid back into circulatory system
Valves prevent backward flow
Lymph flows in only one direction – from body organs to heart
Closely parallel veins
Tissue lymph enter small lymph vessels which drain into larger lymph vessels (lymphatics) into two main lymphatics – the thoracic duct and right lymphatic duct

4. LYMPH NODES Produce lymphocytes Filter out harmful bacteria
If substance can’t be destroyed, node becomes inflamed

5. TONSILS Lymph tissue that produces lymphocytes
They get smaller as a person gets older

6. SPLEEN Produce lymphocytes and monocytes Filter blood
Blood reservoir – stores large amounts of RBCs, contracts during vigorous exercise or loss of blood to release RBCs
Recycles old red cells – destroys and removes old or fragile RBCs

7. THYMUS GLAND
Produces lymphocytes
Also considered an endocrine gland

8. IMMUNITY Body’s ability to resist disease
Natural immunity – at birth, inherited and permanent
Acquired immunity – body’s reaction to invaders
Passive acquired immunity – from injecting antibodies, only lasts a few weeks
Active acquired immunity – lasts longer
Immunization – antigen injected into a person to stimulate production of antibodies
See tables on pages

9. NATURAL IMMUNITY Unbroken skin Mucus and tears Blood phagocytes
Local inflammation

10. ACQUIRED IMMUNITY Active acquired
Natural acquired immunity – result of recovering from disease, body manufactures own antibodies and person doesn’t get the disease again
For example measles
Artificial acquired immunity – from being vaccinated
For example measles: child is given a very mild form allowing the child’s body to be stimulated to make its own antibodies