Photograph by Rich Reid. Tundras are among Earth's coldest, harshest biomes. Tundra ecosystems are treeless regions found in the Arctic and on the tops of mountains, where the climate is cold and windy and rainfall is scant. Tundra lands are snow-covered for much of the year, until summer brings a burst of wildflowers.
Muscle is a soft tissue found in most animals. Muscle cells contain protein filaments of actin and myosin that slide past one another, producing a contraction that changes both the length and the shape of the cell. The statement that the tongue is the strongest muscle in the body appears frequently in lists of surprising facts, but it is difficult to find any definition of strength that would make this statement true. 2  Note that the tongue consists of eight muscles, not one.
There are more than 639 skeletal muscles in your body. Some sources will say 640 muscles in the human body. On average, your body weight is 40% muscle. Out of the 639/640 muscles, 30 of them are facial muscles, which help you create all those different faces of happiness, surprise, joy, sorrow, sadness, fright, etc. The muscles surrounding your eye are the busiest muscles in your body. Research indicates that you probably blink them more than 100,000 times a day.