Lymphatic system

What is the function of the lymphatic system?

• Acts as a secondary circulatory system → transports and filters interstitial fluid (lymph)

• Lymph removes large proteins, particles, and fluid outside cells that are not removed by capillaries

• Responsible for returning tissue fluid to blood

• Also monitors the body for pathogens

What is the central lymphoid organ? What are the two organs?

• site of lymphocyte production and development

• Thymus → site of T cell mutation ( w/o it = lack of functional T-cells)

• Bone Marrow → Produces and replenishes lymphocytes

What are the five peripheral lymphoid tissues?

1. Lymph nodes: Contain leukocytes that filter lymph and can initiate an immune response

2. Spleen: Filters blood → recognises and removes old or damaged RBC

3. Adenoids: Mass of lymphatic tissue → inspect incoming food and air for pathogens

4. Appendix: Contains lymphoid tissue → Can aid in destroying bacteria before they breach the intestinal wall during absorption

5. Peyer’s patches: Large aggregates of lymphoid tissue in the small intestine → Lacteals

Lymphs do not drain into?

• bones

• bone marrow

• teeth

• CNS

The right lymphatic duct drains lymph where? and empties?

• Drains all lymph from the upper right area

• Empties into the jugular vein

The thoracic duct drains lymph where? and empties?

• Drains lymph from the rest of the body

• Empties into the subclavian vein

What are lacteals?

• Lymphatic capillaries in the digestive system

• Located in the villi of the small intestine

• Absorbs fats after they have been emulsified and broken down by digestive enzymes

• Fats can then be brought into circulation