Muscles form the flesh of the body. They give shape (curves) to the body and most importantly, perform the function of movement. Muscles make up approximately fifty percent of our body weight.
There are two main types of muscles:
Voluntary muscles
These muscles are controlled by the central nervous system and are under the control of the will. An example of these muscles would be those that are used in walking.
Involuntary muscles
These muscles are controlled by the autonomic nervous system and are not under the control of the will. An example of these would be those involved with movements of the respiration and digestion systems.
Cardiac muscles
These muscles are only found in the heart. These show a combination of voluntary and involuntary muscles.
