Muscles are made up of tough elastic tissues. These are attached to the bones by a tough band of tissues called tendons. The muscles tighten and relax themselves to produce movement. There are about 640 muscles in your body.
Muscles can only pull the bones. They cannot push them.So, to move the bones, at least two muscles are required. For example, when you bend your arm,one muscles, i.e. biceps contracts and gets shortens,that is the muscles on top become stiff. while the lower muscles, the triceps, stretch. when you stretch back your arm, the upper muscles stretch and the lower muscles contract.
There are three kind of muscles
The muscles which we can control are called voluntary muscles. We can bend or stretch our arms, kick a football with our leg or write with our hands whenever we want. Voluntary muscles control these movement which are further controlled by us.But there are certain muscles we cannot control. Such muscles are called involuntary muscles. Foodie,stomach, intestines and blood vessels are some organs which have involuntary muscles. These muscles are called smooth muscles.
Our heart is made up of a special kind of muscles called cardiac muscles. They are involuntary muscles which work throughout our without getting tired.
