rete mirabile

noun1

1. •
   A complex of blood vessels found in some vertebrates that preserves a gradient of a certain solute or particle, originally specifically the network of arterioles at the base of the brain in some ungulates and other mammals.

   • His description of the rete mirabile, the network of arteries at the base of the brain, shows he dissected animals as well as human corpses, since it does not exist in humans. — 1997