Lymphatic vessels drain interstitial fluid (lymph) from lymphatic spaces, joining eventually to the thoracic ducts and right lymphatic duct which both drain into the venous system.

• Lymph is moved through the vessels primarily by the movement of surrounding organs and tissues.

Examine large and small lymphatic vessels.

• Note the appearance of lymph in the lumens, compared to that of blood in vessels. This is a distinctive, identifying feature of lymphatic vessels.

What is the most important part of the microvasculature? State some of its functions.

What are the 3 general kinds of capillaries and how do their functions differ?

What is the best method to tell a lymphatic vessel from a small vein?

Now for the immune (lymphatic) system.