<n>Tree #10</n> (2006) by South Korean artist <n>Myoung Ho Lee</n>.

A <n>human heart</n> with its blood vessels made visible by plastic injection. Photo by <n>Susumu Nishinaga</n>.

From the photo series <n>Dyal Thak</n> by photographer <n>Kin Coedel</n>.

A polar bear and its reflection, photographed by <n>Paul Nicklen</n> in Hudson Strait, Canada.

<n>Tree, Line</n> by artist <n>Zander Olsen</n>.

A <n>Cerebral angiography</n> showing the <n>Vertebral artery</n> and <n>Basilar artery</n>. Photo by <n>Lucien Monfils</n>.