muscles.txt

  1. Trapezius
    O - Superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of CVII to TXII

    I - Lateral one-third of clavicle, acromion, spine of scapula

    In - Motor-accessory nerve [XI]; proprioception-C3 and C4

    F - Assists in rotating the scapula during abduction of humerus above horizontal; upper fibers elevate, middle fibers adduct, and lower fibers depress scapula
  2. Levator Scapulae
    O - Transverse processes of CI to CIV

    I - Upper portion medial border of scapula

    In - C3 to C4 and dorsal scapular nerve (C4, C5)

    F - Elevates scapula
  3. Latissimus Dorsi
    O - Spinous processes of TVII to LV and sacrum, iliac crest, ribs X to XII

    I - Floor of intertubercular sulcus of humerus

    In - Thoracodorsal nerve (C6 to C8)

    F - Extends, adducts, and medially rotates humerus
  4. Rhomboid Major
    O - Spinous processes of TII to TV

    I - Medial border of scapula between spine and inferior angle

    In - Dorsal scapular nerve (C4, C5)

    F - Retracts (adducts) and elevates scapula
  5. Rhomnoid Minor
    O - Lower portion of ligamentum nuchae, spinous processes of CVII and TI

    I - Medial border of scapula at the spine of scapula

    In - Dorsal scapular nerve (C4, C5)

    F - Retracts (adducts) and elevates scapula
  6. Serratus Posterior Inferior
    O - Spinous processes of TXI to LIII and supraspinous ligaments

    I - Lower border of ribs IX to XII just lateral to their angles

    In - Anterior rami of lower thoracic nerves (T9 to T12)

    F - Depresses ribs IX to XII and may prevent lower ribs from being elevated when the diaphragm contracts
  7. Serratus Posterior Superior
    O - Lower portion of ligamentum nuchae, spinous processes of CVII to TIII and supraspinous ligaments

    I - Upper border of ribs II to V just lateral to their angles

    In - Anterior rami of upper thoracic nerves (T2 to T5)

    F - Elevates ribs II to V
  8. External Intercostal
    O - Inferior margin of rib above

    I - Superior margin of rib below

    In - Intercostal nerves; T1-T11

    F - Most active during inspiration; supports intercostal space; moves ribs superiorly
  9. Pectoralis Major
    O -Clavicular head-anterior surface of medial half of clavicle; sternocostal head-anterior surface of sternum; first seven costal cartilages; sternal end of sixth rib; aponeurosis of external oblique

    I -Lateral lip of intertubercular sulcus of humerus

    In -Medial and lateral pectoral nerves; clavicular head [C5, C6]; sternocostal head [C6, C7, C8, T1]

    F -Flexion, adduction, and medial rotation of arm at glenohumeral joint; clavicular head-flexion of extended arm; sternocostal head-extension of flexed arm
  10. Internal Intercostal
    O -Lateral edge of costal groove of rib above

    I -Superior margin of rib below deep to the attachment of the related external intercostal

    In -Intercostal nerves; T1-T11

    F -Most active during expiration; supports intercostal space; moves ribs inferiorly
  11. Subclavius
    O - First rib at junction between rib and costal cartilage

    I -- Groove on inferior surface of middle one-third of clavicle

    In -Nerve to subclavius [C5, C6]

    F -Pulls tip of shoulder down; pulls clavicle medially to stabilize sternoclavicular joint
  12. Innermost Intercostal
    O -Medial edge of costal groove of rib above

    I -Internal aspect of superior margin of rib below

    In -Intercostal nerves; T1-T11

    F -Acts with internal intercostal muscles
  13. Pectoralis Minor
    O - Anterior surfaces and superior borders of ribs III to V; and from deep fascia overlying the related intercostal spaces

    I -Coracoid process of scapula (medial border and upper surface)

    In - Medial pectoral nerve [C5, C6, C7, C8, T1]

    F -Pulls tip of shoulder down; protracts scapula
  14. Stylohyoid
    O -Base of styloid process

    I -Lateral area of body of hyoid bone

    In -Facial nerve [VII]

    F -Pulls hyoid bone upward in a posterosuperior direction
  15. Serratus Anterior
    O -Lateral surfaces of upper 8-9 ribs and deep fascia overlying the related intercostal spaces

    I -Costal surface of medial border of scapula

    In -Long thoracic nerve [C5, C6, C7]

    F -Protraction and rotation of the scapula; keeps medial border and inferior angle of scapula opposed to thoracic wall
  16. Digastric-Anterior belly
    O -Digastric fossa on lower inside of mandible

    I - Attachment of tendon between two bellies to body of hyoid bone

    In - Mylohyoid nerve from inferior alveolar branch of mandibular nerve [V3]

    F -Opens mouth by lowering mandible; raises hyoid bone
  17. Digastric-Posterior belly
    O -Mastoid notch on medial side of mastoid process of temporal bone

    I -Attachment of tendon between two bellies to body of hyoid bone

    In -Facial nerve [VII]

    F -Pulls hyoid bone upward and back
  18. Geniohyoid
    O -Inferior mental spine on inner surface of mandible

    I -Anterior surface of body of hyoid bone

    In -Branch from anterior ramus of C1 (carried along the hypoglossal nerve [XII])

    F -Fixed mandible elevates and pulls hyoid bone forward; fixed hyoid bone pulls mandible downward and inward
  19. Mylohyoid
    O -Mylohyoid line on mandible

    I -Body of hyoid bone and fibers from muscle on opposite side

    In -Mylohyoid nerve from inferior alveolar branch of mandibular nerve [V3]

    F - Support and elevation of floor of mouth; elevation of hyoid
  20. Sternohyoid
    O - Posterior aspect of sternoclavicular joint and adjacent manubrium of sternum

    I -Body of hyoid bone medial to attachment of omohyoid muscle

    In -Anterior rami of C1 to C3 through the ansa cervicalis

    F -Depresses hyoid bone after swallowing
  21. Omohyoid
    O -Superior border of scapula medial to suprascapular notch

    I -Lower border of body of hyoid bone just lateral to attachment of sternohyoid

    In -Anterior rami of C1 to C3 through the ansa cervicalis

    F - Depresses and fixes hyoid bone
  22. Sternothyroid
    O - Posterior surface of manubrium of sternum

    I -Oblique line on lamina of thyroid cartilage

    In -Anterior rami of C1 to C3 through the ansa cervicalis

    F -Draws larynx (thyroid cartilage) downward
  23. Thyrohyoid
    O -Oblique line on lamina of thyroid cartilage

    I -Greater horn and adjacent aspect of body of hyoid bone

    In -Fibers from anterior ramus of C1 carried along hypoglossal nerve [XII]

    F -Depresses hyoid bone, but when hyoid bone is fixed raises larynx
  24. Deltoid
    O -Inferior angle of the crest of the spine of the scapula, lateral margin of acromion, anterior border of lateral one-third of clavicle

    I -Deltoid tuberosity of humerus

    In -Axillary nerve [C5,C6]

    F -Major abductor of arm (abducts arm beyond initial 15* done by supraspinatus); clavicular fibers assist in flexing the arm; posterior fibers assist in extending the arm
  25. Teres Major
    O -Elongate oval area on the posterior surface of the inferior angle of the scapula

    I -Medial lip of the intertubercular sulcus on the anterior surface of the humerus

    In -Lower (inferior) subscapular nerve [C5,C6.C7]

    F -Medial rotation, adduction, and extension of the arm at the glenohumeral joint
  26. Supraspinatus
    O -Supraspinatus Fossa

    I -Most superior facet on the greater tubercle of the humerus

    In -Suprascapular nerve [C5,C6]

    F -Rotator cuff muscle; initiation of abduction of arm to 15* at glenohumeral joint
  27. Infraspinatus
    O -Infraspinatus Fossa

    I -Middle facet on posterior surface of the greater tubercle of the humerus

    In -Suprascapular nerve [C5,C6]

    F -Rotator cuff muscle; lateral rotation of arm at the glenohumeral joint
  28. Teres Minor
    O -Middle part of lateral border of scapula

    I -Inferior facet on the posterior surface of the greater tubercle of the humerus

    In -Axillary nerve [C5,C6]

    F -Rotator cuff muscle; lateral rotation of arm at the glenohumeral joint
  29. Subscapularis
    O -Subscapular fossa

    I -Lesser tubercle of humerus

    In -Upper & lower subscapular nerves [C5,C6,C7]

    F -Rotator cuff muscle; medial rotation of the arm at glenohumeral joint
  30. Biceps brachii
    O -Long head-supraglenoid tubercle of scapula; short head-apex of coracoid process

    I -Radial tuberosity

    In -Musculocutaneous nerve [C5,C6]

    F -Powerful flexor of the forearm at the elbow joint and supinator of the forearm; accessory flexor of the arm at glenohumeral joint
  31. Triceps brachii
    O -Long head-infraglenoid tubercle of scapula; medial & lateral heads-posterior surface of humerus

    I -Olecranon

    In -Radial nerve [C6,C7,C8]

    F -Extension of the forearm at elbow joint. Long head can also extend & adduct the arm at glenohumeral joint
  32. Coracobrachialis
    O -Apex of coracoid process

    I -Linear roughening on midshaft of humerus on medial side

    In - Musculocutaneous nerve [C5,C6,C7]

    F -Flexor of the arm at glenohumeral joint
  33. Brachialis
    O -Anterior aspect of humerus (medial & lateral surfaces) & adjacent intermuscular septae

    I -Tuberosity of ulna

    In - Musculocutaneous nerve [C5,C6]; (small contribution by radial nerve [C7] to lateral part of muscle)

    F -Powerful flexor of the forearm at elbow joint
  34. Brachioradialis
    O -Proximal part of lateral supraepicondylar ridge of humerus & adjacent intermuscular septum

    I -Lateral surface of distal end of radius

    In -Radial nerve [C5,C6] before division into superficial & deep branches

    F -Accessory flexor of elbow joint when forearm is midpronated
  35. Supinator
    O -Superficial part-lateral epicondyle of humerus, radial collateral & anular ligaments; deep part-supinator crest of ulna

    I -Lateral surface of radius superior to the anterior oblique line

    In -Posterior interosseous nerve [C6,C7]

    F -Supination
  36. Anconeus
    O -Lateral epicondyle of humerus

    I -Olecranon & proximal posterior surface of ulna

    In -Radial nerve [C6,C7,C8] (via branch to medial head of triceps brachii)

    F -Abduction of the ulna in pronation; accessory extensor of elbow joint
  37. Extensor carpi ulnaris
    O -Lateral epicondyle of humerus & posterior border of ulna

    I -Tubercle on base of the medial side of metacarpal V

    In -Posterior interosseous nerve [C7,C8]

    F -Extends & adducts the wrist
  38. Extensor carpi radialis longus
    O -Distal part of lateral supraepicondylar ridge of humerus & adjacent intermuscular septum

    I -Dorsal surface of base of metacarpal II

    In -Radial nerve [C6,C7] before division into superficial & deep branches

    F -Extends and abducts the wrist
  39. Extensor carpi radialis brevis
    O -Lateral epincondyle of humerus & adjacent intermuscular septum

    I -Dorsal surface of base of metacarpals II & III

    In -Deep branch of radial nerve [C7,C8] before penetrating supinator muscle

    F -Extends & abducts the wrist
  40. Extensor digitorum
    O -Lateral epicondyle of humerus & adjacent intermuscular septum & deep fascia

    I -Four tendons, which insert via extensor hoods into the dorsal aspects of the bases of the middle & distal phalanges of the index, middle, ring, & little fingers

    In -Posterior interosseous nerve [C7,C8]

    F -Extends the index, middle, ring, & little fingers; can also extend the wrist
  41. Extensor indicis
    O -Posterior surface of ulna (distal to extensor pollicis longus) & adjacent interosseous membrane

    I -Extensor hood of index finger

    In -Posterior interosseus nerve [C7,C8]

    F -Extends index finger
  42. Extensor digiti minimi
    O -Lateral epicondyle of humerus & adjacent intermuscular septum together with extensor digitorum

    I -Extensor hood of the little finger

    In -Posterior interosseous nerve [C7,C8]

    F -Extends the little finger
  43. Abductor pollicis longus
    O -Posterior surface of ulna & radius (distal to the attachments of supinator & anconeus), & intervening interosseous membrane

    I -Lateral side of base of metacarpal I

    In -Posterior interosseous nerve [C7,C8]

    F -Abducts carpometacarpal joint of thumb; accessory extensor of the thumb
  44. Extensor pollicis longus
    O -Posterior surface of ulna (distal to the abductor pollicis longus) & adjacent interosseous membrane

    I -Dorsal surface of base of distal phalanx of thumb

    In -Posterior interosseous nerve [C7,C8]

    F -Extends interphalangeal joint of the thumb; can also extend carpometacarpal & metacarpophalangeal joints of the thumb
  45. Extensor pollicis brevis
    O -Posterior surface of radius (distal to the abductor pollicis longus) & adjacent interosseous membrane

    I -Dorsal surface of base of proximal phalanx of thumb

    In -Posterior interosseous nerve [C7,C8]

    F -Extends interphalangeal joint of the thumb; can also extend carpometacarpal joint of the thumb
Author
j-sizz
ID
499
Card Set
muscles.txt
Description
origin, insertion,innervation, function
Updated