Anatomy - Shoulder and Posterior Scapula

What are the divisions of the upper extremity?

Shoulder, arm(brachium), forearm(antebrachium), hand

What is the region of transition between the shoulder and the arm?

Axilla (armpit)

What is the region of the transition between the brachium and the antebrachium?

Cubital fossa

What is the region of transition between the antebrachium and the hand?

Carpal tunnel

Where does the brachial plexus pass relative to the clavicle to enter the axilla?

Deep to the clavicle (axillary inlet)

What is the only bone attachment of the upper limb to the trunk?

Clavicle

What three rotator cuff muscles insert on the greater tubercle of the humerus?

• supraspinatus (superior facet)

• Infraspinatus (middle facet)

• Teres minor (inferior facet)

What rotator cuff muscle inserts on the lesser tubercle of the humerus?

Subscapularis

What type of joint is the sternoclavicular joint?

Synovial saddle joint with articular disc

What are the ligaments of the sternoclavicular joint?

• Anterior sternoclavicular ligament

• Posterior sternoclavicular ligament

• Interclavicular ligament

• Costoclavicular ligament

Compare the sternoclavicular joint and the acromioclavicular joint on stability and movement.

Less movement is available at the acromioclavicular joint b/c it is more for stability

What are the ligaments of the acromioclavicular joint?

• acromioclavicular ligament

• Coracoclavicular ligament

What are the parts of the coracoclavicular ligament?

• Trapezoid ligament (attaches at trapezoid tubercle)

• Conoid ligament (attaches at conoid tubercle)

What ligament provides most of the weight-bearing responsibility for the upper limb?

Coracoclavicular ligament

What makes up the glenoid cavity?

Glenoid labrum + fossa

What structure passes through the articular cavity of the glenohumeral joint and is continuous with the glenoid labrum?

Long head tendon of biceps brachii

What is a bursae made of?

Synovial membrane that pierces the joint capsule

What is unique about the synovial membrane of the glenohumeral joint?

It sags inferiorly to form a capsular redundancy to accommodate abduction of the humerus

What are the ligaments associated with the glenohumeral joint?

• Superior/Middle/Inferior glenohumeral ligaments

• Coracohumeral ligament

• Transverse humeral ligament

What ligamentous feature creates capsular weakness in the glenohumeral joint capsule?

Gap between middle and inferior glenohumeral ligaments

What structures provide stability for the glenohumeral joint?

• Coraco-acromial ligament

• Rotator cuff muscles

• Long head of biceps brachii

What thoracic nerve contributes to the brachial plexus?

Intercostobrachial nerve (T2 anterior rami)

What arterial structure branches from the aorta and quickly branches into the R subclavian artery and R common carotid artery?

Brachiocephalic trunk

What venous structures combine to become the superior vena cava?

R and L brachiocephalic trunks (made of R/L subclavian vein and internal jugular vein)

What structure creates the suprascapular foramen from the suprascapular notch?

Coraco-acromial ligament

What neurovasculature move through the suprascapular foramen?

• Suprascapular artery passes over the suprascapular foramen

• Suprascapular nerve passes through the suprascapular foramen

What are the spaces of the shoulder?

• Quadrangular space

• Triangular space

• Triangular interval

What are the borders of the shoulder spaces?

• Quadrangular space - teres minor, long head of tricep brachii, humerus

• Triangular space - teres minor, teres major, long head of tricep brachii

• Triangular interval - long head of triceps brachii, teres major, humerus

What structures pass through each space of the shoulder?

• Quadrangular space - posterior circumflex humeral artery and axillary artery

• Triangular space - circumflex scapular artery

• Triangular interval - profunda brachii artery and radial nerve