“Abby and Brittany Hensel’s anatomy is a remarkable blend of shared and individual organs and tissues,” explained a video created by molecular biologist Hashem Al-Ghaili and shared to their Tiktok in December. “The twins each have their own distinct upper body systems. Abby and Brittany have two heads, two brains, two spinal cords and two hearts, which are part of a shared circulatory system.”
And while Abby, who is on the right side, and Brittany, on the left, share certain systems, including their blood circulation, the 35-year-old sisters’ brains and spinal cords “function independently.”
“Despite this division, their movements are highly coordinated,” the video’s narrator continued. “For activities requiring both arms, such as holding objects, typing on a keyboard or steering a car, they rely on constant cooperation and communication.”
Read on to learn more about Abby and Brittany’s lives.