1 Hydrogen is the most abundant element in the universe. 2  Hydrogen isn't common in a pure form on Earth, but is mostly found as part of water. 3  Hydrogen is the main fuel of stars and the only fuel for red dwarfs. 4  The whole universe is thought to have been formed by a Hydrogen nucleus.
Noun. 1. hindlimb-a posterior appendage such as a leg or the homologous structure in other animals. hind limb. hind leg-the back limb of a quadruped. limb-one of the jointed appendages of an animal used for locomotion or grasping: arm; leg; wing; flipper. 1  Facebook.
The term hindbrain refers to the oldest (evolutionarily speaking) portion of our brain, which is composed of the brainstem (made up of the pons and the medulla oblongata) and the cerebellum. Each of these structures plays a major role in coordinating and controlling the vital automated systems of our body.cientists refer to this 'reptilian' portion as the hindbrain; in other words, the rear portion of the brain. The hindbrain is the region of the brain formed by the pons, medulla oblongata (also known as just the medulla), and the cerebellum.