Anatomy of the muscles of the forehead and eyeball

As for the forehead, it is moved by a thin, wide membranous muscle, which stretches under the skin and is closely adjacent to it, so that it is almost an integral part of the structure of the skin, and it is difficult to remove the skin from it. This muscle adjoins the movable part of the forehead without the mediation of a tendon, since the movable part of the forehead is a wide, light strip of skin, and it would not be good to move it with the help of a tendon. Due to the movement of this muscle, the eyebrows rise; relaxing it helps the eye close.

Anatomy of the muscles of the eyeball

There are six muscles that move the eyeball. Four of them are located on the four sides of the apple: above, below and at both corners of the eye. Each of these muscles moves the eyes in a different direction. Two more muscles are located somewhat askew; they move the apple in a circle. Behind the apple there is a muscle that supports the hollow nerve - we will talk about it later - so that the nerve fits more tightly to it and to what surrounds it. The nerve weighs down this muscle and prevents it from relaxing, which would lead to bulging eyes; therefore, this muscle holds the eye when looking closely. The sheaths of this muscle, which have the appearance of ligaments, are so branched that the nature of this muscle is in doubt. Some anatomists consider it to be one muscle, others - two muscles, and according to others - three muscles. But be that as it may, its extremity is one.