Answer:
small heart-like pumps
Step-by-step explanation:
There is no straight forward pumping activity or opertion in the lymphatic system (it is a group of tissues and organs that aid the elimination of toxins, waste and other unwanted molecules from the body. It helps to move lymph,all through the body). Movement of fluid is reliant on certain basic determinants, for example, gravity and body movement.
The flow of breathing and pressure varies in the thorax and can help with the flow of fluid in the lymphatic vessels.
Therefore,
gravity✔
small heart-like pumps❌
the milking action of muscles✔
pulmonary motion✔
The small heart-like pumps
mechanisms is NOT used to propel lymph through lymphatic vessels