The role of the muscles in performing the movement
The muscular system
The muscular system is the engine that moves our body , where the muscles generate the mechanical energy and the movement to the body due to the ability of the muscular cells to contract and relax .
The muscles are fixed to the bones by the long strips called the tendons , So , when the muscles contract and relax , they move the bones .
The muscular system is responsible for the movement of the human body , It attached to the bones of the skeletal system which are about 650 named muscles that make up roughly half of a person’s body weight .
The human body contains 650 muscles , The biggest muscle in size is at the bottom of the body while the smallest muscle is in the ear , The human use 200 muscles during the walking .
The types of the muscles
There are two types of the muscles which are the voluntary muscles and the involuntary muscles , The voluntary muscles are the muscles that can move willingly , and you can control its movement , The voluntary muscles as the limbs muscles , the trunk muscles , the face muscles and the abdominal wall muscles .
The involuntary muscles are the muscles that can move automatically and you can not control or even aware of their movement , The involuntary muscles as the gastrointestinal tract , the blood vessels , and the bladder muscles .
The role of the muscles in the movement of the fore arms
The front muscle contracts and the back muscle relaxes , this causes the bending ( moving up ) of the arm by the help of the elbow joint .
The front muscle relaxes and the back muscle contracts , this causes extending ( move down ) of the arm by the help of the elbow joint .
The effect of the contraction or the relaxation of the muscles is transferred to the elbow joint bones by the tendons that links between the muscles and the bones .