Pectoral Region and Upper Limb

Deltoid

Proximal Attachment: Clavicle, acromion, spine of the scapula

Distal Attachment: Deltoid tuberosity of the humerus

Innervation: Axillary nerve (C5,6)

Actions: Clavicular - flexion and medial rotation; Acromial - Abduction; Spinal - extension and lateral rotation

Pectoralis Major

Proximal Attachment: Medial clavicle, sternocostal (anterior sternum, superior costal cartilages, external oblique muscle, aponeurosis)

Distal Attachment: Lateral crest of intertubercular groove

Innervation: Lateral (C5-C7) and medial (C8-T1) pectoral nerve

Actions: Adduction and medial rotation of humerus, stabilize the scapula, clavicular - flexion, sternocostal - extension from flexed position

Pectoralis Minor

Proximal Attachment: Superior ribs

Distal Attachment: Coracoid process of scapula

Innervation: Medial pectoral nerve (C8-T1)

Action: Stabilize scapula

Subclavius

Proximal Attachment: 1st rib

Distal Attachment: Inferior surface of clavicle

Innervation: Nerve to subclavius (C5, C6)

Action: Anchor and depress clavicle

Serratus anterior

Proximal Attachment: Superior and middle ribs

Distal Attachment: Anterior surface of medial scapular border

Innervation: Long thoracic nerve (C5-C7)

Action: Protract and superiorly rotate scapula

What muscles control the abduction of the shoulder?

0-15 degrees - supraspinatus

15-90 degrees - deltoid

>90 degrees - trapezius and serratus anterior

What muscles are in the rotator cuff?

Supraspinatus
Infraspinatus

Teres minor

Subscapularis

“Sub in, SIT out”

Supraspinatus

Proximal Attachment: Supraspinous fossa of scapula

Distal Attachment: Greater tubercle of humerus

Innervation: Suprascapular nerve (C5,6)

Action: Initiates abduction of arm and lateral rotation of arm (weak)

Infraspinatus

Proximal Attachment: Infraspinous fossa of scapula

Distal Attachment: Greater tubercle of humerus

Innervation: Suprascapular nerve (C5,6)

Action: Lateral rotation of arm

Teres Minor

Proximal Attachment: Middle of lateral scapular border

Distal Attachment: Greater tubercle of humerus

Innervation: Axillary nerve (C5,6)

Action: Lateral rotation of arm

Teres Major

Proximal Attachment: Inferior scapular border

Distal Attachment: Medial lip of intertubercular sulcus of humerus

Innervation: Lower subscapular nerve (C6)

Action: Adduction and medial rotation of arm

Subscapularis

Proximal Attachment: Subscapular fossa (anterior scapula)

Distal Attachment: Lesser tubercle of humerus

Innervation: Upper (C5) and lower (C6) subscapular nerves

Action: Medial rotation of arm

What muscles are part of the anterior compartment of the arm?

Biceps brachii, coracobrachialis, and brachialis

Biceps brachii

Proximal Attachment:

Short head - coracoid process of scapula

Long head - supraglenoid tubercle

Distal Attachment: Proximal radius and fascia (bicipital aponeurosis)

Innervation: Musculocutaneous nerve (C5-C7)

Action: Supination of the forearm and flexion of the arm when supinated

Coracobrachialis

Proximal Attachment: Coracoid process of scapula

Distal Attachment: Mid-shaft of humerus

Innervation: Musculocutaneous nerve (C5-C7) - pierced by

Action: Flexion and adduction of arm

Brachialis

Proximal Attachment: Distal half of humerus

Distal Attachment: Coronoid process and tuberosity of ulna

Innervation: Musculocutaneous nerve (C5-C7)

Action: Flexion of forearm

Triceps brachii

Proximal Attachment:

Long head: infraglenoid tubercle of scapula

Lateral head: Posterior humerus, superior to radial groove

Short/Medial head: Posterior humerus, inferior to radial groove

Distal Attachment: Proximal olecranon of ulna

Innervation: Radial nerve (C5-C8, T1)

Action: Extension of forearm

Where does the cephalic vein run in the pectoral region?

Through the deltopectoral groove

What artery is this?

Subclavian artery

What artery is this?

Internal thoracic artery

What artery is this?

Perforating branches

What artery is this?

Lateral thoracic artery

What artery is this?

Pectoral branch of the thoracoacromial trunk

What artery is this?

Thoracoacromial trunk

What artery is this?

Axillary artery