1 Each muscle fibre ( muscle cell ) is covered by a plasma membrane sheath which is called the sarcolemma. 2  Tunnel-like extensions from the sarcolemma pass through the muscle fibre from one side of it to the other in transverse sections through the diameter of the fibre.keletal muscles consist of 100,000s of muscle cells (also known as muscle fibers) that perform the functions of the specific muscle of which they are a part.
Green vegetables are also a major source of iron and calciumfor any diet. Swiss chard and spinach are not considered good sources of calcium, due to their high content of oxalic acid. Green leafy vegetables are rich in beta-carotene, which can also be converted into vitamin A, and also improve immune function. Millions of children around the world have an increased risk of blindness, and other illnesses because of inadequate dietary vitamin A from green leafy vegetables.
Green leafy vegetables like spinach, Swiss chard, collard, turnip greens and kale are some of the best sources of vitamin E. 100 grams serving of spinach can help you meet 10% of the daily value of vitamin E. Swiss chard provides 16% and turnip greens provide 13% of the daily value.