Final answer:
Skeletal muscles, categorized mainly into axial and appendicular muscles, are essential for movement and are named based on physical and functional characteristics. Muscles of facial expression move the skin to create expressions, and skeletal muscles function in pairs with their fascicle arrangement affecting their range of motion.
Step-by-step explanation:
Skeletal muscles are an integral component of the human body, with over 600 different muscles that can be categorized into two main groups: axial and appendicular muscles. The axial muscles consist of those in the trunk and head, while the appendicular muscles include those in the arms and legs. Muscles serve various functions and are named according to a variety of criteria such as shape, size, location, number of origins, and action. An example is the tibialis anterior, which is named for its location and association with the anterior tibia bone.
Muscles of facial expression originate on the skull's surface, and their contraction moves the skin to create expressions. Skeletal muscles are made up of muscle fibers that are cylindrical and can be large, such as those in the upper leg. These muscle fibers contain multiple nuclei, which is beneficial for muscle function.
In terms of movement, skeletal muscles work in pairs, commonly referred to as prime movers and antagonists based on their functions. Their connection to the bones and the arrangement of their fascicles, like parallel, circular, and convergent, determine the force, speed, and range of their movement, and ultimately, their interaction with the skeletal system.