Assertion: porcupine's body | /r/Causes | warm arterial blood
Facets:
value: to exchange heat
type: PURPOSE
Source sentences:
text: In the CCHE mechanism, in cold weather, blood vessels are closely knotted and intertwined with arteries to the skin and appendages that carry warm blood with veins returning to the body that carry cold blood causing the warm arterial blood to exchange heat with the cold venous blood.