Assertion: giraffe's head | /r/HasProperty | raised
Facets:
Source sentences:
text: A giraffe’s height requires a specialized, large heart to pump blood to the brain as well as unusually elastic blood vessels with a series of valves that help offset the sudden build up of blood when the head is raised, lowered or swung quickly.
text: The neck vessels are equipped with numerous one-way valves that prevent blood from back flowing to the brain when the head is lowered, and muscle fibers surrounding the veins slow the flow of blood when the head is raised again.