Age of oceanic crust: youngest (red) is along spreading centres. Seafloor spreading happens at the bottom of an ocean as tectonic plates move apart. The seafloor moves and carries continents with it. At ridges in the middle of oceans, new oceanic crust is created. At the Mid-Atlantic Ridge (and other places), material from the upper mantle rises through the faults between oceanic plates. It forms new crust as the plates move away from each other. The new crust then slowly moves away from the ridge. Seafloor spreading helps explain continental drift in plate tectonics. Earlier theories (e.g. by Alfred Wegener) of continental drift were that continents 'plowed' through the ocean.
The nervous system. Sweating is regulated by the sympathetic division of the autonomic nervous system, over which we have little control. Its major role is to prevent overheating of the body. The nervous system. <br /><br /><br /> Sweating is regulated by the sympathetic division of the autonomic nervous system, over which we have little control.
Most of our sweat is released by the eccrine sweat glands, which are stimulated when the body is hot. When stimulated, these glands release a watery substance onto the skin. When this moisture evaporates, the body cools down.