Skeletal muscles are named based on several criteria each of which focuses on particular structural or functional characteristics of a muscle.
Location of the muscle
Some muscles are given names that indicate the bone or body region that they lie close to or are attached to. For example, the temporalis muscle overlies the temporal bone and the intercostal muscles run between the ribs/intercostal area.
Shape of the muscle
Since muscles sometimes have distinct shapes this factor is normally used for naming of muscles. For example, the deltoid muscle group is roughly triangular or deltoid shape. Another example is the trapezius muscle, which forms a trapezoid.
Size of the muscle
The size of the muscle is sometimes used in the naming of the muscle for example minimus, Maximus, longus, and brevis are terms used in the names of many muscles. Minimus meaning small, Maximus being large, brevis meaning short and longus meaning long.
Direction of muscle fibers
Some muscles are named based on the alignment or direction of the muscle fibers. For example some muscles have the word rectus in the name and rectus refers to straight, other muscles have transverse or oblique in the name and that means that they run in an angle.
Number of origins of muscle
Some muscles are named for the amount of origins that they attach to for example. Biceps, triceps or quadriceps in the case of biceps its means two, triceps refers to three and quadricep to four origins.
Location of the muscles origins and/or insertion
Some muscles are named based on their origin and insertion for example sternocleidomastoid is named because the muscle of the neck attaches to the sternum and the clavicle and it inserts to the mastoid process of the temporal bone.
