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.
The muscular system is responsible for the movement of the human body. Attached to the bones of the skeletal system are about 700 named muscles that make up roughly half of a personâs body weight.Each of these muscles is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves.Muscle tissue is also found inside of the heart, digestive organs, and blood vessels. In these organs, muscles serve to move substances throughout the body....he main function of the muscular system is movement. Muscles are the only tissue in the body that has the ability to contract and therefore move the other parts of the body. Related to the function of movement is the muscular systemâs second function: the maintenance of posture and body position.