High pressure in the lymphatic vessels, contraction of the tunica media, and elastic recoil of connective tissues in the vessel walls push lymph through the vessels. valves in the lymphatic vessels push lymph toward the heart. gravity keeps lymph flowing toward the heart contraction of surrounding muscles and pulsing of adjacent arteries move lymph through lymphatic vessels toward the heart.

The blue particles in this image are able to cross the cell membrane through simple diffusion. how will they be transported? outside the cell inside the cell o a. the substances will move directly across the membrane from outside the cell to inside the cell. b. the substances will move through channels in the membrane proteins from outside the cell to inside the cell. o c. the substances will move through channels in the membrane proteins from inside the cell to outside the cell. o d. the substances will move directly across the membrane from inside the cell to outside the cell.