Entry of lymph into the lymphatic capillaries is promoted by which of the following?
a. One-way minivalves formed by overlapping endothelial cells
b. The respiratory pump
c. The skeletal muscle pump
d. Greater fluid pressure in the interstitial space

Lymphatic capillaries are tiny, blind-ended vessels with overlapping endothelial cells that form one-way minivalves. These minivalves open when interstitial fluid pressure is high, allowing fluid to enter but preventing backflow, thus promoting lymph entry into the lymphatic system.

Fluid movement into lymphatic capillaries depends on pressure differences between the interstitial space and the lymphatic lumen. Higher pressure in the interstitial fluid pushes fluid into the capillaries, aided by the minivalves, facilitating lymph formation.

The respiratory pump and skeletal muscle pump help propel lymph through larger lymphatic vessels by creating pressure changes during breathing and muscle contractions. However, they do not directly promote fluid entry into lymphatic capillaries.