Muscles of the Upper Limb Flashcards
What is the origin of the pectoralis major?
Medial half of clavicle and anterior surface of sternum, first seven costal cartilages, aponeurosis of external oblique
What is the insertion of the pectoralis major?
Lateral lip of intertubercular sulcus of humerus
What is the action of the pectoralis major?
Adduction, medial rotation and flexion of the humerus at the shoulder joint
What is the innervation of the pectoralis major?
Medial and lateral pectoral nerves
What is the origin of the pectoralis minor?
Anterior surfaces of the third, fourth and fifth ribs, and deep fascia overlying the related intercostal spaces
What is the insertion of the pectoralis minor?
Coracoid process of scapula
What is the action of the pectoralis minor?
Depresses tip of shoulder, protracts scapula
What is the innervation of the pectoralis minor?
Medial pectoral nerves
What is the origin of the subclavius?
Rib I at junction between rib and costal cartilage
What is the insertion of the subclavius?
Groove on inferior surface of middle third clavicle
What is the action of the subclavius?
Pulls clavicle medially to stabilise sternoclavicular joint; depresses tip of shoulder
What is the innervation of the subclavius?
Nerve to subclavius
What is the origin of the serratus anterior?
Anterior portions of first 8 ribs
What is the insertion of the serratus anterior?
Internal surface of medial border of scapula
What is the action of the serratus anterior?
Holds scapula against ribcage to prevent ‘winging’ of the inferior angle of the scapula
What is the innervation of the serratus anterior?
Long thoracic nerve
What is the origin of the trapezius muscle?
Skull, ligamentum nuchae and the spinous processes of C7-T12
What is the insertion of the trapezius muscle?
Clavicle, acromion and the spine of the scapula
What is the action of the trapezius muscle?
Elevation, rotation, retraction and depression of the scapula
What is the innervation of the trapezius muscle?
Accessory nerve
What is the origin of the latissimus dorsi?
Spinous processes of T6-T12, thoracolumbar fascia, iliac crest, and the inferior three ribs
What is the insertion of the latissimus dorsi?
Intertubercular sulcus of the humerus
What is the action of the latissimus dorsi?
Extension, adduction and medial rotation of the upper limb
What is the innervation of the latissimus dorsi?
Thoracodorsal nerve
What is the origin of the levator scapulae?
Transverse processes of the C1-C4 vertebrae
What is the insertion of the levator scapulae?
Medial border of the scapula
What is the action of the levator scapulae?
Elevation of the scapula
What is the innervation of the levator scapulae?
Dorsal scapular nerve
What is the origin of the rhomboid major?
Spinous processes of T2-T5 vertebrae
What is the insertion of the rhomboid major?
Medial border of the scapula, between the scapula spine and inferior angle
What is the action of the rhomboid major?
Retracts and rotates the scapula
What is the innervation of the rhomboid major?
Dorsal scapular nerve
What is the origin of the rhomboid minor?
Spinous processes of C7-T1 vertebrae
What is the insertion of the rhomboid minor?
Medial border of the scapula, at the level of the spine of scapula
What is the action of the rhomboid minor?
Retracts and rotates the scapula
What is the innervation of the rhomboid minor?
Dorsal scapular nerve
What is the origin of deltoid?
Lateral third of clavicle, acromion and spine of scapula
What is the insertion of deltoid?
Deltoid tuberosity of humerus
What is the action of deltoid?
- clavicular (anterior) part: flexes and medially rotates arm
- acromial (middle) part: abducts arm
- spinal (posterior) part: extends and laterally rotates arm
What is the innervation of deltoid?
Axillary nerve (C5, C6)
What is the origin of supraspinatus?
Supraspinous fossa of scapula
What is the insertion of supraspinatus?
(Superior facet of) greater tubercle of humerus
What is the action of supraspinatus?
Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles
What is the innervation of supraspinatus?
Suprascapular nerve (C4, C5, C6)
What is the origin of infraspinatus?
Infraspinous fossa of scapula
What is the insertion of infraspinatus?
(Middle facet of) greater tubercle of humerus
What is the action of infraspinatus?
Laterally rotates arm, and acts with rotator cuff muscles
What is the innervation of infraspinatus?
Suprascapular nerve (C5, C6)
What is the origin of teres minor?
Middle part of lateral border of scapula
What is the insertion of teres minor?
Inferior facet of greater tubercle of humerus
What is the action of teres minor?
Laterally rotates arm, and acts with rotator cuff muscles
What is the innervation of teres minor?
Axillary nerve (C5, C6)
What is the origin of teres major?
Posterior surface of inferior angle of scapula
What is the insertion of teres major?
Medial lip of intertubercular sulcus of humerus
What is the action of teres major?
Adducts and medially rotates arm
What is the innervation of teres major?
Lower subscapular nerve (C5, C6)
What is the origin of subscapularis?
Subscapular fossa (most of the anterior space of scapula)
What is the insertion of subscapularis?
Lesser tubercle of humerus
What is the action of subscapularis?
Medially rotates arm, as part of rotator cuff - helps hold head of humerus in glenoid cavity
What is the innervation of subscapularis?
Upper and lower subscapular nerves (C5, C6, C7)
What is the origin of biceps brachii?
- Short head: tip of coracoid process of scapula
- Long head: supraglenoid tubercle of scapula
What is the insertion of biceps brachii?
Tuberosity of radius and fascia of forearm via bicipital aponeurosis
What is the action of biceps brachii?
- Supinates forearm and, when supine, flexes forearm
- Short head resists dislocation of shoulder