1. The Lymphatic System & Immunity

2. Functions:
Lymph – Fluid that goes between capillary blood and tissues.
Lymph Vessels – transport excess tissue fluid back into circulatory system.
Lymph Nodes – Produce lymphocytes, filter out harmful bacteria
Spleen – produces lymphocytes and monocytes, blood reservoir, recycles old red blood cells.
Thymus Gland – produces T-Lymphocytes

3. Lymph – straw colored fluid similar to plasma
Composed of:
Water
Lymphocytes
Some granulocytes
Oxygen
Digested nutrients
Hormones
Salts
Carbon Dioxide
Urea
NO red blood cells or protein molecules

4. Functions of Lymph
Carries digested food, Oxygen and hormones to cells.
Carries waste back to capillaries for excretion.
Propelled via skeletal muscle action (contraction & relaxation) one way, unlike blood, which is pumped via the heart

5. Lymph Vessels Pathway:
Lymph from the left side of chest, the head and neck, abdominal area and lower limbs flow into the THORACIC DUCT.
Thoracic Duct to the left subclavian vein
Left subclavian vein to the superior vena cava
Superior Vena Cava to the heart

6. Enlarged cervical lymph node
Lymph Nodes
Tiny, oval shaped structures the size of a pinhead to the size of an almond
Located alone or grouped
Site for lymph production
Filter for screening out harmful substances
If substance cannot be destroyed, the node becomes inflamed!
Enlarged cervical lymph node

7. Tonsils and Adenoids
Masses of lymphatic tissue that produce lymphocytes.
Filter bacteria
Get smaller with age
Adenoids
Tonsils

8. Spleen Sac-like mass of lymphatic tissue
Located in upper left abdominal cavity, immediately inferior to the diaphragm
Functions:
Forms lymphocytes and monocytes
Filters blood
Stores large amounts of RBCs
Destroys or removes old or fragile RBCs

9. Thymus Gland Located in the upper, anterior thorax, above the heart
Also considered an endocrine gland
Shrinks as you get older