Most axons of vertebrates are enclosed in a myelin sheath, which increases the speed of impulse transmission; some large axons may transmit impulses at speeds up to 90 metres (300 feet) per second.
Lynda Carter Wonder Woman's STILL SUPER HOT. 61-year-old Lynda Carter -- famous for playing Wonder Woman on the '70s show -- must really have super powers ... because she's still scorchin' hot.
How are there even people out there like this?! Michelle Carter, an 18-year-old from Massachusetts, is facing involuntary manslaughter charges after she allegedly encouraged her online boyfriend to commit suicide via text message. [ Related: WDBJ Anchors Deliver A Touching Tribute To Co-Workers ]