Muscles of the Shoulder Girdle and Arm Flashcards
What muscles make up the rotator cuff?
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
What is the origin of the Supraspinatus?
Supraspinous Fossa
Where is the Supraspinatus located?
above the spine of the scapula
What is the insertion of the Supraspinatus?
Greater Tubercle (Sup. Facet)
What is the innervation of the supraspinatus?
Suprascapular nerve (C5, C6)
What is the action of the Supraspinatus?
Shoulder ABduction
Where is the infraspinatus located?
Below the spine of scap
What is the origin of the infraspinatus?
Infraspinatus Fossa
What is the insertion of the infraspinatus?
Greater Tubercle (Mid. Facet)
What is the innervation of the infraspinatus?
Suprascapular Nerve (C5, C6)
What is the action of the infraspinatus?
Shoulder Lateral Rotation
Where is the teres minor located?
Humeral head to lateral border of scap
What is the origin of the teres minor?
Sup. part of lat. border of scapula
What is the insertion of the teres minor?
Greater Tubercle (Inf. Facet)
What is the innervation of the teres minor?
Axillary Nerve (C5, C6)
What is the action of the teres minor?
Shoulder Lateral Rotation
Where is the subscapularis?
On the underside of the scapula
What is the origin of the subscapularis?
subscapular fossa
What is the insertion of the subscapularis?
Lesser Tubercle of humerus
What is the innervation of the subscapularis?
Upper and lower subscapular nerves (C5, C6, C7)
What is the action of the subscapularis?
Shoulder medial rotation, ADduction
What muscles stabilise the scapula and clavicle?
Trapezius
Levator Scapula
Rhomboids Major and Minor
Serratus Anterior
Pectoralis Major
Pectoralis Minor
Subclavius
What is the origin of the serratus anterior?
External surfaces of lateral parts of 1st to 8th ribs
What is the insertion of the serratus anterior?
Anterior surface of medial border of scapula
What is the innervation of serratus anterior?
Long thoracic nerve (C5, C6, C7)
What is the action of the serratus anterior?
Protracts scapula and holds it against the thoracic wall
What is the origin of the trapezius?
Medial third of superior nuchal line, external occipital protuberance, nuchal ligament, and spinous processes of C7-T12 vertebrae
What is the insertion of the trapezius?
Lateral third of clavicle, acromion, and spine of scapula
What is the innervation of the trapezius?
Spinal roots of Accessory nerve (CN XI), motor; cervical nerves (C2,C3, C4), (pain and proprioception
What is the action of the trapezius?
Elevation of clavicle, Elevation and lateral rotation of Scapula, Adduction, lateral rotation, retraction
What is the origin of the pectoralis major?
Clavicular head: Anterior surface of medial half of clavicle
Sternocostal head: Anterior surface of sternum, superior 6 costal cartilages, aponeurosis of external oblique muscle
What is the insertion of pectoralis major?
Lateral lip of intertubercular groove of humerus
What is the innervation of pectoralis major?
Lateral and medial pectoral nerves
Clavicular head (C5, C6), Sternocostal head (C7, C8, T1)
What is the action of pectoralis major?
Shoulder adduction (horizontal), Flexion, medial rotation, draws scapula anteriorly & inferiorly
What is the origin of Levator Scapulae?
Posterior tubercles of transverse processes C1-C4 vertebrae
What is the insertion of Levator Scapulae?
Superior part of medial border of scapula
What is the innervation of Levator Scapulae?
Dorsal scapular (C5) and cervical (C3, C4) nerves
What is the action of Levator Scapulae?
Elevates scapula & tilts its glenoid cavity inferiorly by rotating the scapula
What is the origin of the Rhomboid Minor and Major Muscles?
Minor: Spinous processes C7-T1
Major: Spinous processes T2-T5
What is the insertion of Rhomboid Minor and Major Muscles?
Medial border of scapula from level of spine to inferior angle
What is the innervation of Rhomboid Minor and Major Muscles?
Dorsal scapular nerve (C4, C5)
What is the action of Rhomboid Minor and Major Muscles?
Scapula retraction, fix scapula to thoracic wall
What is the origin of Pectoralis Minor?
3rd-5th ribs near costal cartilages
What is the insertion of Pectoralis Minor?
Coracoid process of scapula
What is the innervation of Pectoralis Minor?
Medial pectoral nerve (C8, T1)
What is the action of Pectoralis Minor?
Stabilises scapula by drawing it inferiorly and anteriorly against the thoracic wall
What is the origin of the subclavius?
Junction of first rib and its costal cartilage
What is the insertion of the subclavius?
Inferior surface of middle third of clavicle
What is the innervation of the subclavius?
Nerve to subclavius C5,6
What is the action of the subclavius?
Anchors and depresses the Clavicle
What is the origin of the Latissimus Dorsi?
Spinous processes of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribs
What is the insertion of the Latissimus Dorsi?
Floor of intertubercular groove of humerus
What is the innervation of the Latissimus Dorsi?
Thoracodorsal nerve (C6, C7, C8)
What is the action of the Latissimus Dorsi?
Shoulder extension, adduction, medial rotation, raises body towards arms during climbing
What is the origin of the deltoid?
Lat third of clavicle, acromion, spine of scapula
What is the insertion of the deltoid?
Deltoid tuberosity of humerus
What is the innervation of the deltoid?
Axillary nerve (C5, C6)
What is the action of the deltoid?
Anterior Part: Shoulder Flexion, Medial Rotation
Middle Part: Shoulder Abduction
Posterior Part: Shoulder Extension, Lateral Rotation
What are the muscles that move the arm?
Deltoid
Teres Major
Coracobrachiallis
Latissimus dorsi
What is the origin of the Biceps Brachii?
Short Head: Tip of coracoid process of scapula
Long Head: Supraglenoid tubercle of scapula
What is the insertion of the Biceps Brachii?
Tuberosity of radius, fascia of forearm via bicipital aponeurosis
What is the innervation of the Biceps Brachii?
Musculocutaneous Nerve (C5, C6)
What is the action of the Biceps Brachii?
Elbow flexion and supination, Flexes shoulder joint
What is the origin of the Brachialis?
Distal half of anterior surface of humerus
What is the insertion of the Brachialis?
Coronoid process and ulnar tuberosity
What is the innervation of the Brachialis?
Musculocutaneous nerve (C5, C6)
What is the action of the Brachialis?
Elbow flexion
What is the origin of the Coracobrachialis?
Tip of coracoid process of scapula
What is the insertion of the Coracobrachialis?
Middle third of medial surface of humerus
What is the innervation of the Coracobrachialis?
Musculocutaneous nerve (C5, C6)
What is the action of the Coracobrachialis?
Shoulder flexion, adduction
What is the origin of the Triceps Brachii?
Long Head: Infraglenoid tubercle of scapula
Lateral Head: Posterior surface of humerus, superior to radial groove
Medial Head: Posterior to humerus, inferior to radial groove
What is the insertion of the Triceps Brachii?
Olecranon of ulna
What is the innervation of the Triceps Brachii?
Radial nerve (C6, C7, C8)
What is the action of the Triceps Brachii?
Elbow extension