The skeleton could not move our bodily features without the help of the muscles attached to the skeleton. Bones are required for movement but they are unable to move on their own. They must be moved by the alternate contraction and relaxation of the skeletal muscles. Many bones have ridges and protuberances which provide an area for muscle attachment. Muscles make up nearly half of the mass of a human and are the dominant tissue of the musculoskeletal system, the cardiovascular system, and the walls of all the hollow organs of the body.
Skeletal muscles act on the bones that serve as a system of levers. The limbs bend at their joints, so they can move by the action of the skeletal muscles. The joints allow movement between bones and these movements are directly related to the type of joint and range of motion. In terms of positioning, the joint can only make one movement, like your arms can only move up and down and can only move slightly side to side.
For every muscle or group of muscles that brings about movement of a certain part of the body, there is another muscle or group of muscles which bring about an opposite movement. These are called antagonistic muscles. These muscles make the smooth co-ordination of movement possible. As one muscle contracts, the other will create an opposite movement which will cause the muscle to relax.
When a muscle is stimulated it contracts and becomes shorter and thicker which will then move the bone to which it is attached. When it is relaxed, the muscle becomes longer and thinner. Muscles can only do work by pulling as they contract. A muscle is unable to do work by pushing as it elongates.
Skeletal muscles act on the bones that serve as a system of levers. The limbs bend at their joints, so they can move by the action of the skeletal muscles. The joints allow movement between bones and these movements are directly related to the type of joint and range of motion. In terms of positioning, the joint can only make one movement, like your arms can only move up and down and can only move slightly side to side.
For every muscle or group of muscles that brings about movement of a certain part of the body, there is another muscle or group of muscles which bring about an opposite movement. These are called antagonistic muscles. These muscles make the smooth co-ordination of movement possible. As one muscle contracts, the other will create an opposite movement which will cause the muscle to relax.
When a muscle is stimulated it contracts and becomes shorter and thicker which will then move the bone to which it is attached. When it is relaxed, the muscle becomes longer and thinner. Muscles can only do work by pulling as they contract. A muscle is unable to do work by pushing as it elongates.
