General discussion of muscles, nerves, tendons and ligaments

Voluntary movements are carried out by organs only thanks to the force flowing to them from the brain through the nerves. Nerves cannot connect well with bones, which, in essence, are, according to the original plan, the basis for moving organs during movement, for the bones are hard and the nerves are thin. And here is the creator, great is he! - grew from bones something similar to nerves and called “veins” or “ligaments”, connected them with nerves and wove them into something single. But a body composed of nerves and ligaments is, in any case, thin, for the nerves, connecting with other organs, do not allow such an increase in volume compared to the volume and thickness at the place of their origin, which should be taken into account. And the volume of nerves at their origin corresponds to what the substance of the brain and spinal cord allows, as well as the volume of the head and the width of the exit points of the nerves. If the nerves were entrusted with moving the organs of the body, maintaining their possible volume, especially when the nerves diverge, divide and branch, so that the share of the nerve per organ would be much less than its root, when the nerve moves away from its origin and the place of exit, then obvious harm would result from this.

And here is the creator, great is he! - determined, in his wisdom, to give thickness to the nerves by dividing the body formed from the nerves and from the ligaments into threads, filling the gaps with meat, enveloping the nerves in a sheath and placing in the middle a support like an axis made of the same substance as the substance of the nerves. The totality of all this forms an organ consisting of nerves, tendons and their fibers, as well as meat, which serves as a filling, and an enveloping membrane. This organ is a separate muscle. When it contracts, it pulls on the tendon, which consists of a ligament and nerves that are directed towards the given member, and the tendon contracts and pulls on that member of the body. And when the muscle is stretched, the tendon weakens and this member of the body moves away.