Assertion: giraffe | /r/HasAspect | valve
Facets:
value: within their circulatory system
type: LOCATION
Source sentences:
text: To compensate for the sudden increase in blood pressure when the head is lowered, the giraffe has very elastic blood vessels and valves in the venous system of the neck.
text: They also have valves within their circulatory system to dilate and constrict as necessary.