Soft tissue Soft tissue In anatomy, soft tissue includes the tissues that connect, support, or surround other structures and organs of the body, not being hard tissue such as bone. Soft tissue includes tendons, ligaments, fascia, skin, fibrous tissues, fat, and synovial membranes (which are connective tissue), and muscles, nerves and blood vessels (which are not connective tissue). It is sometimes defined by what it is not. Soft tissue has been defined as "nonepithelial, extraskeletal mesenchyme exclusive of the reticuloendothelial system and glia". The characteristic substances inside the extracellular matrix of this kind of tissue are the collagen, elastin and ground substance.
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;