There are three different types of muscles in the human body: smooth muscles, cardiac muscles, and skeletal muscles. Of these, we can only voluntarily control the skeletal muscles. We do not have control over smooth muscles and cardiac muscles and they work without our conscious effort.
Smooth muscles usually occur in sheets or layers, one on top of the other. Some examples of smooth muscles are the ones in our digestive system, that relax and tighten to control the movement of food through our body. Another example is the muscles in our bladder that (when relaxed) allow storage of urine and (when contracted) push the urine out of our body.
Cardiac muscles form our heart and work without conscious effort from the body. These muscles allow the entry of blood into heart (when relaxed) and pump it out (when contracted).
The human body is composed of three types of muscles: skeletal, smooth, and cardiac.
-Skeletal muscle is the only muscle type under conscious control (voluntary muscles) controlled through the somatic nervous system; they are connected to bones and provide the mechanical force needed to move.
-Smooth muscle are not under our control (involuntary muscles, they are controlled by what is called the autonomic nervous system). Smooth muscles can be found in the digestive system, mediating the movement of food or can be found surrounding blood vessels mediating blood pressure.
-Cardiac muscles are not under our control (involuntary muscles, they are controlled by what is called the autonomic nervous system). Cardiac muscles are found in the heart, the organ that is responsible for pumping blood though our circulatory system.
We have three types of muscles in our bodies -- cardiac, smooth, and skeletal. Most of our muscles work without us even thinking about them. Even while you're sleeping your heart is pumping blood, your respiratory muscles are helping you breathe, and food is being moved through your digestive system. These and other automated processes in our bodies are helped along or controlled by what are called involuntary muscles. That means they do their job whether you think about them or not. All of the cardiac and smooth muscles in your body are involuntary. The other muscles, the skeletal ones, are the only ones you have direct control over. As such, skeletal muscles are often referred as to as voluntary muscles.