1. LYMPHATIC SYSTEM
STRUCTURE

2. LYMPH Straw-colored, similar to plasma
Diffuses from the capillaries into the tissue spaces
Interstitial fluid (tissue fluid)– in spaces b/t cells
Composed of water, lymphocytes, oxygen, digested nutrients, hormones, salts, carbon dioxide, and urea
No red cells or proteins (too large to diffuse)

3. LYMPH VESSELS Closely parallel veins
Form an extensive and branchlike system throughout the body
Located in almost all tissues and organs that have blood vessels
Not in cuticles, nails, hair, cartilage, CNS, red marrow, epidermis, eyeballs, inner ear, or spleen
Thoracic duct – largest lymph vessel
Responsible for spreading cancer cells
SEE FIGURE 15-1 pg 311 and FIGURE 15-2 pg 312

4. LYMPH NODES Tiny, oval shaped, size of pinhead to size of almond
Each covered by a capsule of fibrous connective tissue that extends into the node
Located alone or grouped in various places along the lymph vessels
Consists of different kinds of lymphocytes
Lymph sinuses (spaces b/t lymph tissue) contain macrophages
Microorganisms or foreign substances stimulate the production of lymphocytes (immune response)

5. TONSILS
Masses of lymphatic tissue which are capable of producing lymphocytes and filtering bacteria
Play an important role in the line of defense against infection
Get smaller as person gets older
Located in throat
Adenoids – tonsils on upper part of throat
Tonsillitis
Inflamed, infected tonsils

6. SPLEEN Sac-like mass of lymphatic tissue
Located near upper left abdominal cavity, just below diaphragm
Forms lymphocytes and monocytes
Filters blood and stores large amounts of RBCs
Destroys and removes old or fragile RBCs

7. THYMUS GLAND
Located in the upper anterior part of the chest, above the heart
Consists largely of lymphatic tissue
Produces lymphocytes (T-lymphocytes)