Muscles Of The Superficial Back And Shoulder Flashcards
Trapezius origin and insertion
O: external occipital protuberance, superior nuchal line, ligamentum nuchae (fascia surrounding spinal column), spinous process of C7 to T12
I: acromion process, spine of the scapula, lateral aspect of the clavicle
Trapezius innervation and action
Innervation: spinal accessory nerve (cranial nerve IX)
Action: upward scapular rotation, ipsilateral side bending, contralateral rotation of the neck
Upper fibers- elevate the scapula
Lower fibers- depress the scapula
Middle fibers- retract the scapula
Latissimus dorsi origin and insertion
O: iliac crest, lower three or four ribs, thoracolumbar fascia, lumbar and sacral vertebrae, inferior angle of the scapula
I: intertubercular groove of the humerus
Latissimus dorsi innervation and action
Innervation: thoracodorsal nerve (C5-C7)
Action: shoulder extension, internal rotation, and adduction
Rhomboids origin and insertion
O: spinous processes of C7 to T5
I: medial border of the scapula
Rhomboids innervation and action
Innervation: dorsal scapular nerve (C5)
Action: scapular retraction and downward rotation
Levator scapulae origin and insertion
O: posterior tubercles of the transverse processes of C1 to C4 vertebrae
I: superior angle of the scapula
Levator scapulae innervation and action
Innervation: dorsal scapular nerve (C5)
Action: elevates scapulae, downward scapular rotation. Also ipsilateral side bending, and rotation of the neck
Deltoid origin and insertion
O: acromion process, spine of the scapula, lateral aspect of the clavicle
I: deltoid tuberosity of the humerus
Deltoid innervation and action
Innervation: axillary nerve (C5-C6)
Action: anterior fibers- flex and internally rotate the shoulder
posterior fibers- extend and externally rotate the shoulder
middle fibers- abduct the shoulder
Posterior deltoid - major horizontal abduction
Supraspinatus origin and insertion
O: supraspinous fossa of the scapula
I: greater tubercle of the humerus
Supraspinatus innervation and action
Innervation: suprascapular nerve (C5-C6)
Action: shoulder abduction
Infraspinatus origin and insertion
O: infraspinous fossa of the scapula
I: greater tubercle of the humerus
Infraspinatus innervation and action
Innervation: suprascapular nerve (C5-C6)
Action: shoulder external rotation
Teres minor origin and insertion
O: lateral border of the scapula
I: greater tubercle of the humerus
Teres minor innervation and action
Innervation: axillary nerve (C5-C6)
Action: shoulder external rotation
Subscapularis origin and insertion
O: subscapular fossa
I: lesser tubercle of the humerus
Subscapularis innervation and action
Innervation: upper and lower subscapular nerve (C6-C8)
Action: shoulder internal rotation
Teres major origin and insertion
O: inferior angle of the scapula
I: intertubercular groove of the humerus
Teres major innervation and action
Innervation: lower subscapular nerve (C6-C8)
Action: shoulder internal rotation, adduction
Rotator cuff
Supraspinatus Infraspinatus Teres minor Subscapularis Function: to increase dynamic stability of the glenohumeral joint
Quadrangular space
Superior border: subscapularis (ant) and the teres minor (post)
Inferior border: teres major
Medial border: long head of the triceps
Lateral border: surgical neck of humerus
Axillary nerve and posterior circumflex humeral artery runs through this space
3 branches of the aortic arch
Right brachiocephalic artery
Left subclavian artery
Left common carotid artery
Right brachiocephalic division
Right subclavian artery
Right common carotid artery
3 parts of the subclavian artery
Part 1 goes from the brachiocephalic artery to the anterior scalene
Part 2 goes behind anterior scalene
Part 3 goes from the anterior scalene to the lateral aspect of the first rib where the vessel changes names and becomes the axillary artery
3 parts of the axillary artery
Part 1 goes from the lateral aspect of the first rib to the pectoralis minor
Part 2 goes behind the pectoralis minor
Part 3 goes from the pectoralis minor to the inferior border of the teres major where it changes names again and becomes the brachial artery
The brachial artery will run down into the cubital fossa
Axilla borders
Anterior wall: pectoralis major and minor
Posterior wall: subscapularis, latissimus dorsi, and teres major
Medial wall: serratus anterior
Lateral wall: intertubercular groove of he humerus
Axilla contents
Axillary artery
Cords of the brachial plexus
SH/LH biceps and coracobrachialis
Long thoracic nerve
