List of Muscles and Function - San Diego Miramar College

1 List of Muscles and Function Region View Muscle Function Facial Anterior/Oblique Occipitofrontalis front belly Raises eyebrows Orbicularis oculi Closes eye Orbicularis oris Purses lips Zygomaticus minor/major Elevates & retracts lip and mouth Buccinator Compresses cheeks Depressor anguli oris Depress corner of mouth Facial Lateral Masseter Elevate mandible/close jaw Principle masticator Temporalis Elevates jaw, masticator Neck Anterior Platysma Depress mandible, tense neck Sternocleidomastoid Flex neck together Rotate head to opposite side alone Anterior Omohyoid Depress hyoid & larynx deep section Sternohyoid Depress hyoid & larynx Abdomen Anterior Rectus abdominis Vertebral flexion /compression External oblique Vertebral flexion /rotation/comp deep section Internal oblique Vertebral flexion /rotation/comp deep section Transversus abdominis Compress abdomen deep section Diaphragm Quiet respiration Shoulder Posterior Trapezius Elev/depress/ Girdle Serratus anterior Abduction, upward rotation Rhomboid major/minor Adduction.

2 Downward rotation Anterior deep section Pectoralis minor Abduction, downward rotation Shoulder Posterior Latissimus dorsi Adduct, inward rotation, extension Joint Teres major Adduct, inward rotation, extension *Supraspinatus Abduction and stabilization *Infraspinatus Adduction, outward rotation *Teres minor Adduction, outward rotation Anterior ribs removed *Subscapularis Adduction, inward rotation *Above four comprise the Rotator Cuff Anterior Pectoralis major flexion , inward rotation, Coracobrachialis Adduction, flexion Biceps brachii flexion Triceps brachii long head Extension Post/Lat/Ant Deltoid all fibers Abduct, ant.

3 Fibers post. fibers outrot/flex Elbow Joint Anterior Biceps brachii flexion , supination of hand Brachialis flexion Brachioradialis flexion . Pro/supination to midpos. Posterior Triceps brachii Extension 58. Region View Muscle Function Wrist & Hand Anterior Long Flexors Flexor carpi radialis flexion of wrist and hand Palmaris longus flexion of wrist and hand Flexor carpi ulnaris flexion of wrist and hand Posterior Long Extensors Extensor carpi radialis long. Extension of wrist and hand Extensor digitorum Extension of wrist and hand Extensor carpi ulnaris Extension of wrist and hand Hip Joint Anterior Iliopsoas deep section Iliacus flexion , outward rotation Psoas major flexion , outward rotation Quadriceps femoris Rectus femoris only flexion Sartorius flexion , outward rotation Medial Gracilis Adduction Pectineus flexion , adduction Adductor longus Adduction, flexion Posterior Gluteus maximus Extension, lateral rotation Hamstrings Semitendinosus Extension Semimembranosus Extension Biceps femoris long head Extension Lateral Tensor fasciae latae Iliotibial tract flexion .

4 Stabilizes knee Gluteus medius Abduction Knee Joint Anterior Quadriceps femoris Rectus femoris Extension Vastus lateralis Extension Vastus medialis Extension deep section Vastus intermedius Extension Posterior Hamstrings Semitendinosus flexion Semimembranosus flexion Biceps femoris both heads flexion Sartorius flexion Gracilis flexion Gastrocmenius flexion Ankle Joint Anterior Tibialis anterior Dorsiflexion Lateral Fibularis longus Eversion Posterior Gastrocnemius Plantarflexion Soleus Plantarflexion Be able to identify all of the above Muscles on charts and models 59. Be able to identify actions for all of the above Muscles Be able to also list the attachments (origin and insertion) for Bolded Muscles Attachments are listed below Principle Skeletal Muscles Thoracic Muscles Rectus Abdominus Origin: Pubis & Symphysis Pubis Insertion: Ribs & Sternum Action: Compresses abdomen, flexes vertebral column External Obliques Origin: Lateral Ribs Insertion: Ilium & linea alba Action: Compress abdomen, rotates & laterally flexes vertebral column Internal Obliques Origin: Ilium & inguinal ligament Insertion: Lower ribs Action.

5 Compresses abdomen, rotates & laterally flexes vertebral column Transverse Abdominus Origin: Ilium & lower ribs Insertion: Sternum, Linea alba, pubis Action: Compresses Abdomen for: forced experation, micturition, defecation, emesis, & parturition Diaphragm Origin: Dome shaped sheet, vertebrae, ribs & sternum Insertion: Central tendon Action: Floor of thoracic cavity Resperation: contracts & flattens=inspiration Relaxes & rises=exhalation Shoulder Girdle Muscles Trapezius Flat sheet of muscle on upper back. Four Muscles Origin: Occipital bone, ligamentum nuchae, C7-T12 spinous processes Insertion: Outer clavicle, spine & acromion of scapula Action: Elevation, Depression, Adduction & Up.

6 Rot. of Scap. Pectoralis Minor Small anterior, upper chest deep to pec major Origin: Ribs 3-5 near costal cartilage Insertion: Coracoid process of scapula Action: Depression, Abduction & Downward Rotation Serratus Anterior Sawtoothed insertion Origin: Lateral ribs 1-8/9. Insertion: Entire anterior, medial border of scapula Action: Abduct & upward rotation of scapula 60. Shoulder Joint Muscles Deltoid Origin: Acromion & spine of scapula, clavicle Insertion: Detloid tuberosity of humerus Action: Abducts, flexes, extends (horiz.) rotates (in. & out.). Supraspinatus Origin: Supraspinous fossa of scapula Insertion: Top of greater tubercle of humerus Action: Abduction of shoulder joint <90 , prevents dislocation Infraspinatus Origin: Infraspinus fossa of scapula Insertion: Greater tubercle of humerus Action: Outward rotation, extension (horiz), adduction Teres Minor Origin: Inferior lateral border of scapula Insertion: Greater tubercle of humerus (w/ infraspinatus).

7 Action: Outward rotation, extension (horiz), adduction Subscapularis Origin: Subscapular fossa of scapula Insertion: Lesser tubercle of humerus Action : Inward rotation ** Above four Muscles Rotator Cuff **. Latissimus Dorsi Origin: T7-L5 spinous processes, Post. iliac crest & sacrum, Insertion: Medial border of intertubercular groove of humerus Action: Adduction, extension, inward rotation Pectoralis Major Origin: Clavicle, Sternum, Costal cartilages of ribs 2 - 6. Insertion: Lateral border of intertubercular groove of humerus Action: Adduction, Extension Horizontal flexion Teres Major Origin: Lateral border to inferior angle of scapula Insertion: Medial border of intertubercular groove of humerus Action: Adduction, Inward rotation, Extension Elbow Joint Muscles Biceps Brachii Actions at 3 joints Origin: Long Head: Supraglenoid tubercle of scapula Short Head: Coracoid process of scapula Insertion: Radial tuberosity ** Display changes in length**.

8 Action: Flexes elbow, supinates hand, Flexes shoulder joint (Long Head). 61. Brachialis "Upper Arm Muscle". Origin: Inferior, anterior humerus Insertion: Below coronoid process on the tuberosity of ulna Action: flexion of elbow (workhorse of flexors). Brachioradialis Origin: Lateral inferior humerus Inserton: Styloid process of radius Action: Elbow flexion (strongest at midposition). Pronation & Supination to midposition Triceps Brachii Origin: Long Head: Infraglenoid tubercle of humerus Lateral & Medial Head: Post humerus Insertion: Olecranon of unla Action: Elbow extension Extension of shoulder joint (long head). Muscles of Forearm of Wrist Long Flexors Origin: Anterior medial epicondyle of humerus Inserion: Palmar surface of wrist & hand Action: flexion of wrist & fingers Long Extensors Origin: Posterior, lateral epicondyle of humerus Insertion: Dorsal surface of wrist & hand Action: Extension of wrist & fingers Hip Joint Muscles Iliopsoas Origin: Iliac fossa, sides of bodies T12-L5 vertebrae Insertion: Lesser trochanter of femur Action: flexion & outward rotation of hip joint Extension of lumbar vertebrae Gluteus Maximus Origin: Posterior ilum, sacrum & cocyx Insertion: Lateral femur Action.

9 flexion & outward rotation of hip joint Adductors Origin: Pubis Insertion: Medial & posterior femur Action: Adduction & outward rotation Hamstrings - Biceps Femoris, Semimembranosus &Semitendinosus Origin: Ischial tuberosity Insertion: Biceps Femoris: Head of fibula & lateral tibia Semimembranosus &Semitendinosus: Medial tibia Action: Extension of hip & flexion of knee 62. Sartorius (Longest) Tailor's Origin: ASIS. Insertion: Medial tibial tuberosity Action: Flexes hip & knee Gracilis Origin: Symphysis pubis & pubis Inserton: Medial tibia Action: Adduction of hip Knee Joint Muscles Quadriceps Origin: Rectus Femoris: AIIS.

10 Vastus Lateralis, Vastus Medialis, Vastus Intermedius: Femur Insertion: Tibial tuberosity via patellar ligament Action: Extension of knee (RF Hip Flex.). Hamstrings Action: flexion of knee Ankle Joint Muscles Gastrocnemius Origin: Posterior femoral epicondyles Inserton: Calcaneus via Achille's Tendon Action: Plantarflexion, knee flexion Soleus Origin: Posterior tibia & fibula Insertion; Calcaneus via Achille's Tendon Action: Plantarflexion 63.