It may seem like a jumble of meaningless Latin at first, but muscle names follow a strict convention that names them according to one or more of the following:
Function: These muscle names usually have a verb root and end in a suffix (–or or –eus), followed by the name of the affected structure. Example: levator scapulae (elevates the scapulae).
Compounding points of attachment: These muscle names blend the origin and insertion attachment with an adjective suffix (–eus or –is). Examples: sternocleidomastoideus (sternum, clavicle, and mastoid process) and sternohyoideus (sternum and hyoid).
Shape or position: These muscle names usually have descriptive adjectives that may be followed by the names of the locations of the muscles. Examples: rectus (straight) femoris, rectus abdominis, and serratus (sawtooth) anterior.
Figurative resemblance: These muscle names are based on the muscles’ resemblance to some objects. Examples: gastrocnemius (resembles the stomach) and trapezius (resembles a trapezoid or kite shape).
Check out the figure and the following table for a rundown of prominent muscles in the body and key points to remember about each one.
![[Credit: Illustration by Kathryn Born, MA]](https://cdn.prod.website-files.com/6634a8f8dd9b2a63c9e6be83/6698d462be50268194d6a3ad_462744.image0.jpeg)
Credit: Illustration by Kathryn Born, MA
| Muscle | Origin | Insertion | Action |
|---|---|---|---|
| Head | |||
| Frontalis | Galea aponeurotica | Eyebrow | Expression |
| Occipitalis | Occipital bone | Galea aponeurotica | Moves scalp forward and backward |
| Buccinator | Alveolar processes of mandible and maxillary bone | Orbicularis oris and skin at angle of mouth | Mastication |
| Orbicularis oculi | Encircles eye | Encircles orbit and extends within eyelid | Closes eye |
| Orbicularis oris | Encircles mouth | Skin surrounding mouth and at angle of mouth | Closes mouth |
| Masseter | Zygomatic arch | Mandible | Mastication |
| Temporalis | Temporal fossa | Coronoid process and ramus of mandible | Mastication |
| Zygomaticus | Zygomatic bone | Corner of mouth | Smiling |
| Neck | |||
| Sternocleidomastoid | Manubrium of sternum and median portion of clavicle | Mastoid process of temporal bone | Rotation and flexion of neck vertebrae |
| Back | |||
| Latissimus dorsi | Vertebral column | Humerus | Extends at shoulder joint |
| Trapezius | Occipital bone and vertebral column (7 cervical vertebrae and all thoracic vertebrae) | Clavicle and scapula | Rotates, elevates, depresses, adducts, and stabilizes scapula |
| Pectoral girdle | |||
| Pectoralis major | Sternum, clavicle, upper 6 ribs, and aponeurosis of external oblique muscle | Medial margin of tertubercular groove of humerus | Flexion, rotation, and adduction of shoulder joint |
| Shoulder | |||
| Deltoid | Lateral third of clavicle, acromion process, and spine of scapula | Deltoid tuberosity of humerus | Abduction, flexion, rotation, and extension of arm, using coordinated fibers: entire muscle (abduction); interior fibers (flexion); medial fibers (rotation); posterior fibers (extension); and lateral fibers (rotation) of arm |
| Abdominal wall | |||
| External abdominal oblique | External surface of lower 8 ribs | Aponeurosis to linea alba and anterior half of iliac crest | Stabilizes, protects, and supports internal viscera, compresses abdominal cavity, assists in flexing and rotating vertebral column |
| Internal abdominal oblique | Inguinal ligament, iliac crest, and lumbodorsal fasciae | Linea alba, pubic crest, and last 3 ribs | Stabilizes, protects, and supports internal viscera, compresses abdominal cavity, assists in flexing and rotating vertebral column |
| Transversus abdominis | Inguinal ligament, iliac crest, lumbodorsal fasciae, and costal cartilage of last 6 ribs | Linea alba and pubic crest | Stabilizes, protects, and supports internal viscera, compresses abdominal cavity, assists in flexing and rotating vertebral column |
| Rectus abdominis | Pubic crest and symphysis pubis | Xiphoid process of sternum and costal cartilage of ribs 5–7 | Stabilizes, protects, and supports internal viscera |
| Thorax | |||
| Diaphragm | Xiphoid process of sternum, inner surface of lower 6 ribs, and lumbar vertebrae | Central tendon of diaphragm | Pulls central tendon downward, increasing size of thoracic cavity and causing inspiration; separates thoracic and abdominal cavities |
| External intercostals | Inferior border of rib above and costal cartilage | Superior border of rib below rib of origin | Elevates ribs, aiding inspiration |
| Internal intercostals | Superior border of rib below and costal cartilage | Inferior border of rib above rib of origin | Depresses ribs, aiding inspiration |
| Arm | |||
| Biceps brachii | Long head: Tubercle above glenoid fossaShort head: Coracoid process of scapula | Tuberosity of radius | Flexion at elbow joint |
| Triceps brachii | Long head: Infraglenoid tubercle of scapulaLateral head: Posterior surface of humerus above radial grooveMedial head: Posterior surface of humerus above radial groove | Olecranon process of ulna | Extension of elbow joint |
| Flexor carpi radialis | Medial epicondyle of humerus | 2nd to 3rd metacarpals | Flexor of wrist, abducts hand |
| Flexor carpi ulnaris | Medial epicondyle of humerus and olecranon process | Pisiform bone and base of 5th metacarpal | Flexor of wrist, adducts hand |
| Supinator | Lateral epicondyle of humerus and proximal end of ulna | Proximal end of radius | Supinates forearm |
| Extensor carpi ulnaris | Lateral epicondyle of humerus | Base of 5th metacarpal | Extends and adducts wrist |
| Extensor carpi radialis longus | Lateral supracondylar ridge of humerus | Base of 2nd metacarpal | Extends and abducts wrist |
| Extensor carpi radialis brevis | Lateral epicondyle of humerus | Dorsal surface of 3rd metacarpal | Extends and abducts wrist, steadies wrist during finger flexion |
| Thigh, Anterior (Front) | |||
| Rectus femoris (part of quadriceps) | Acetabulum of coxal bone | Tibial tuberosity via patella | Extends knee and flexes thigh at hip |
| Vastus lateralis (part of quadriceps), vastus medialis, vastus intermedialis (part of quadriceps) | Femur | Tibia | Extends knee |
| Sartorius | Anterior superior iliac spine | Proximal medial surface of tibia | Flexes at knee and laterally rotates thigh |
| Adductors | Pubis | Femur | Adduction and flexion at hip joint and lateral rotation of thigh |
| Gracilis | Pubis, symphysis pubis, and pubic arch | Medial surface of tibia | Adduction of thigh and rotation of leg |
| Thigh, Posterior (Back) | |||
| Biceps femoris (part of hamstrings) | Long head: Ischial tuberosityShort head: Linea aspera | Fibula and lateral condyle of tibia | Flexion at knee, extension of thigh |
| Semimembranosus (part of hamstrings) | Ischial tuberosity | Medial condyle of tibia | Flexion at knee, extension of thigh |
| Semitendinosus (part of hamstrings) | Ischial tuberosity | Proximal end of tibia | Flexion at knee, extension of thigh |
| Leg, Posterior | |||
| Gastrocnemius | Medial and lateral condyles of femur | Calcaneus by Achilles (calcaneal) tendon | Flexion at knee and plantar flexion |
| Soleus | Posterior third of fibula and middle third of tibia | Calcaneus by Achilles tendon | Plantar flexion |
| Hip | |||
| Gluteus maximus | Dorsal ilium, sacrum, and coccyx | Glutual tuberosity of femur | Extends thigh and laterally rotates thigh |
