Collagen hereditary link. Collagen is one of the long, fibrous structural proteins whose functions are quite different from those of globular proteins, such as enzymes. Tough bundles of collagen called "collagen fibers" are a major component of the extracellular matrix that supports most tissues and gives cells structure from the outside, but collagen is also found inside certain cells. Collagen has great tensile strength, and is the main component of fascia, cartilage, ligaments, tendons, bone and skin. Along with elastin and soft keratin, it is responsible for skin strength and elasticity, and its degradation leads to wrinkles that accompany aging. It
Muscle from the Latin "musculus" meaning "little mouse" perhaps because of the shape of certain muscles or because contracting muscles look like mice moving under the skin. The anatomy of muscles includes gross anatomy, which comprises all the muscles of an organism, and microanatomy, which comprises the structures of a single muscle. Muscle tissue is a soft tissue, and is one of the four fundamental types of tissue present in animals. There are three types of muscle tissue recognized in vertebrates: Cardiac and skeletal muscles are "striated" in that they contain sarcomeres that are packed into highly regular arrangements of bundles;