Assertion: vein | /r/CapableOf | squeeze venous blood
Facets:
value: toward the heart
type: TRANSITIVE-OBJECT
value: toward the presence of valves
type: TRANSITIVE-OBJECT
Source sentences:
text: b. Blood pressure is maintained in veins by contractions of the smooth muscle in the walls of the veins that squeeze venous blood toward the heart and the presence of valves which prevent backflow of the blood.