Types of Muscle

Muscles can be categorized into three types based on structure and function. These categories are skeletal muscles, smooth or visceral muscles, and cardiac muscles. The structure and function of these muscle types are as follows.

Skeletal Muscles

Skeletal muscles are also known as striated or voluntary muscles. They form a significant part of the musculoskeletal system and are responsible for the locomotion and movement of body parts. These muscles are cylindrical and are characterized by the presence of multiple nuclei and striations. Striations are caused by a repeating unit in the muscle fiber called the sarcomere. Sarcomeres have alternating thick filaments of myosin that give a dark band (red) and a thin filament of actin that gives a light band (white). This alternating dark and light band gives rise to the striated appearance of skeletal muscles.

Skeletal muscles are attached to the bones by tendons. These muscles are under conscious control and are responsible for voluntary movements such as walking, running, and lifting. They are vital in providing structural support and maintaining posture. These muscles are also responsive to neural signals in response to external stimuli.

Also Read: Difference Between Ligaments and Tendons

Smooth Muscles

Smooth muscles are also called non-striated, visceral, or involuntary muscles. These muscles do not have any striations in their fibers and are spindle-shaped, with only one nucleus per myocyte. Smooth muscles are found in the walls of internal organs, such as the stomach, intestines, and blood vessels. Smooth muscles are involuntary and operate without conscious control. They perform tasks regulated only by internal nervous signaling and not external stimuli. They have essential roles in digestion, like swallowing, blood vessel constriction, and other internal organ movements.

Cardiac Muscles

Cardiac muscles are found only in the heart. They can be identified by the branched appearance of their fibers, striated and uninucleated fibers. These muscles are unique as they possess striations like skeletal muscles but work involuntarily like smooth muscles. They maintain the rhythmic pumping of blood throughout the circulatory system.

Also Read: Difference Between Cardiac Muscle And Skeletal Muscle

The muscular system is composed of muscle fibers that enable the body to move, maintain posture, and circulate blood. It consists of three different types of muscles: the skeletal muscles, cardiac muscles, and visceral muscles. The essential function of the muscular system is to support involuntary and voluntary movement and to maintain stability and posture in all living organisms. In this article, we will discuss the muscular system, its types, functions, and disorders that can affect its functioning.