The five kingdoms ( Monera ) > Muscles

Muscular System

A popular and traditional Halloween costume is that of a skeleton. Could a skeleton really walk by itself? What do you think? we learn that skeletons have the important job of providing our bodies with strength and form. The task of moving our bodies from one place to another belongs to another part of our bodies known as muscles. Without muscles we could not move.

Our bodies are made up of a variety of very large and very small muscles. From the powerful leg muscles that you use when you jump up and down to the tiny muscles that make your eyes blink, anytime you move, you are using muscles. In fact, as you read this article on our website you are using muscles to move your eyes back and forth. Scientists have estimated that about 40%, or almost half, of your body is muscle.

 

What Are These Things We Call Muscles

There are three different types of muscles within your body. Each muscle type is different because it has a different type of job to do. Each muscle type is specialized to perform the important tasks that keep you alive. These three muscle types are Skeletal Muscles, Smooth Muscles, and Cardiac Muscles.

Skeletal Muscles / Striated Muscles

Skeletal muscles are usually attached to bones. They are often called striated muscles because of their striated, or striped appearance. The cells of skeletal muscles can be very long, sometimes over 30 cm, and can contain many different nuclei. Your brain usually tells your skeletal muscles what to do. Skeletal muscles are manly used in movement, such as when you wiggle your toes, wave your hand, and smile.

Smooth Muscles Your body contains many muscles which are not under the control of your brain, but rather operate on their own without instructions. These muscles are called smooth muscles because they appear smoother than other muscles. Smooth muscles can be found throughout your body, including in your stomach, in your blood vessels, in your digestive system, and in your eyes. They are used to move food through your digestive system, regulate blood flow, and decrease the size of your pupils when there is too much light. Smooth muscle cells are smaller than skeletal muscle cells and only have one nuclei. Also, unlike skeletal muscle cells, smooth muscle cells don’t have striations, or stripes. Smooth muscle cells are connected directly to one another, allowing electrical pulses to pass through them.

Cardiac Muscles

Cardiac muscle is a special type of tissue that is only found within your heart. Did you know your heart is actually a very strong muscle? Like skeletal muscle cells, cardiac muscles cells are striated, or striped. Like smooth muscle cells, cardiac muscle cells are not under the control of your brain, but instead operate independently. Also like smooth muscle cells, the cells of your heart are connected directly to one another, allowing electrical pulses to flow through them.