1. Naming Skeletal Muscles
Claudio Hernandez
P.3

2. Overview
Like bones, muscles come in many shapes and sizes to suit their particular tasks in the body. Muscles are distinguished by their characteristics of their functions and structure.

3. Functions of Skeletal Muscles
Skeletal muscle moves the skeleton and is responsible for all our voluntary movements, as well as for the automatic movements required.
For example, to stand, to hold up our head, and to breathe.
(Other involuntary functions involve smooth muscle and cardiac muscle.)

4. Direction of the muscle fibers
 Some muscles are named in reference to some imaginary line, usually the midline of the body or the long axis of a limb bone. When a muscle’s name includes the term rectus (straight), its fibers run parallel to that imaginary line.
For example, the rectus femoris is the straight muscle of the thigh, or femur.
Similarly, the term oblique as part of a muscle’s name tells you that the muscle fibers run obliquely (at a slant) to the imaginary line.

5. Relative size of the muscle
Such terms as maximus (largest), minimus (smallest), and longus (long) are often used in the names of muscles.
For example, the gluteus maximus is the largest muscle of the gluteus muscle group.

6. Number of origins
When the term biceps, triceps, or quadriceps form s part of a muscle name, one can assume that the muscle has two, three, or four origins, respectively.
For example, the biceps muscle of the arm has two heads, or origins, and the triceps muscle has three.

7. Location of the muscle’s origin and insertion
Occasionally, muscles are named for their attachment sites.
For example, the sternocleidomastoid muscle has its origin on the sternum (sterno) and clavicle (cleido) and inserts on the mastoid process of the temporal bone.

8. Shape of the muscle
Some muscles have a distinctive shape that helps to identify them. For example, the deltoid muscle is roughly triangular (deltoid means “triangular”).
Action of the muscle

9. Action of the muscle
When muscles are named for their actions, names like flexor, extensor, and adductor appear in their names.
For example, the adductor muscles of the thigh all bring about its adduction, and the extensor muscles of the wrist all extend the wrist.

10. Major Skeletal Muscles (1)
Head and Neck
Frontalis
Orbicularis oris
Orbicularis oculi
Occipitofrontalis
Zygomaticus major
Masseter
Sternocleidomastoid
Trapezius
Buccinator
Muscles of the Trunk
External Intercostals
Internal Intercostals
Transverse abdominis
Infraspinatus
Rectus abdominis
Serratus anterior
Diaphragm

11. Major Skeletal Muscles (2)
Move Upper Extremities
Pectoralis major
Latissimus dorsi
Deltoid
Teres major
Biceps brachii
Triceps brachii
Brachialis
Brachioradialis
Palmaris longus
Flexor carpi radialis.
Flexor digitorum superficialis
Extensor carpi radialis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris
Move the Lower Extremities
Iliopsoas
Sartorius
Gluteus maximus
Gluteus medius
Tensor fasciae latae
Adductor longus
Gracilis
Semimembranosus
Semitendinosus
Biceps femoris
Rectus femoris
Vastus lateralis
Vastus intermedium
Vastus medialis
Tibialis anterior
Gastrocnemius
Soleus
Peroneus longus
Peroneus brevis

12. Questions Are Skeletal muscles voluntary or involuntary? Why?
What causes the striations of a skeletal muscle cell?
What’s your favorite muscle? Why?

13. Bibliography
Kopach, Jennifer Major Skeletal Muscle List (n.d.): n. pag. List of 50 Major Skeletal Muscles for Jennifer Kopach, 1 Jan Web. 14 Dec
University, Oxford. "Skeletal Muscle." The Oxford Companion to the Body. Encyclopedia.com, 1 Jan Web. 14 Dec
Marieb, Elaine N. "Essentials of Human Anatomy & Physiology, 9th Edition." Essentials of Human Anatomy & Physiology, 9th Edition. Elaine N Marieb, 24 Aug Web. 14 Dec