beneath the skin there is a layer composed of connective tissue. In some places this laver binds the skin directly to the bones and in others it separates the skin from the muscles. One can see the subcutaneous fat in this layer which is called fascia.
The skin and this fascia form a protective covering for the muscles, bones and internal organs. The muscles are formed by the mass of muscle cells. The muscles are held together by the connective tissue. There are the blood vessels and the nerves in our body. They supply the muscles.
The covering of the bone is composed of a fibrous connective tissue. It is called the periosteum. To this the muscles are attached, directly or indirectly, by means of a tough band called tendon.
Whenever a muscle contracts the points of attachment are brought closer together.