ANATOMY-UPPER EXTREMITY

What are the primary functions of the upper extremity?

To position the hand for interaction with the environment

What forms the pectoral (shoulder) girdle?

Clavicle (SC joint) and scapula (AC joint)

Which joint connects the upper extremity to the axial skeleton?

Sternoclavicular (SC) joint

What type of articulation exists between the scapula and thoracic wall?

Scapulothoracic articulation (muscular)

What bone connects the upper limb to the trunk?

Clavicle

What are the functions of the clavicle?

Protects neurovascular structures, transmits force, stabilizes scapula

What injury is common with a lateral impact to the shoulder?

Clavicle fracture

Between which ribs does the scapula lie?

Ribs 2 to 7

What are the posterior surface features of the scapula?

Supraspinous fossa, spine, and infraspinous fossa

What are the anterior surface features of the scapula?

Subscapular fossa and coracoid process

What is the glenoid cavity?

Articulating surface for the head of the humerus

What structure deepens the glenoid cavity?

labrum

What bones articulate to form the acromioclavicular (AC) joint?

Acromion of scapula and lateral clavicle

What is the difference between the anatomic and surgical neck of the humerus?

Anatomic neck is near the head; surgical neck is a common fracture site and more distal

What structures attach to the greater and lesser tubercles of the humerus?

Rotator cuff muscle tendons

What is located in the intertubercular (bicipital) groove?

bicipital groove for long head of the biceps tendon

What nerve and artery run in the radial groove?

Radial nerve and profunda brachii artery

What nerve is at risk with a midshaft humeral fracture?

Radial nerve

Which nerves pass anterior to the elbow joint?

Radial and median nerves

Which nerve passes posterior to the elbow joint?

Ulnar nerve

At what site is the ulnar nerve commonly injured?

Posterior to the medial epicondyle (funny bone)

What bone is lateral in the forearm?

Radius

What bone is medial in the forearm?

Ulna

What bones articulate at the elbow joint?

Humerus, radius, and ulna

where does the proximal radial head articulate?

capitulum of humerus (flex/extend elbow) and medially with the ulna (pronation/supination)

where does the distal head of the radius articulate?

head of ulna, scaphoid, and lunate carpals

What motion occurs between the radius and ulna?

Pronation and supination

Which carpal bone is most commonly fractured?

Scaphoid (falling on an outstretched hand)

Why are proximal scaphoid fractures problematic?

Poor blood supply may lead to avascular necrosis (gets retrograde blood supply)

How many bones make up the hand?

27 bones, 5 metacarpus, 14 phalanges (don't need to know wrist but there is 8)

What does the antebrachial fascia distally form at the wrist?

Extensor and flexor retinacula

What forms the roof of the carpal tunnel?

Flexor retinaculum

What passes through the carpal tunnel?

Flexor tendons and the median nerve

what is the primary source of the vascular supply to the UE?

axillary artery

where does the brachial artery end ?

the antecubital fossa

What arteries supply the upper extremity in order?

Subclavian → Axillary → Brachial → Radial and Ulnar arteries

What are the terminal branches of the brachial artery?

Radial and ulnar arteries

which artery descends medial through the anterior compartment of the antebrachium (arm)?

ulnar artery

which artery descends lateral through anterior compartment of the antebrachium (arm)?

radial artery

Where can the axillary artery pulse be palpated?

In the axilla or inferior to the pectoralis minor

What is the purpose of the Allen's test?

To assess collateral blood flow through radial and ulnar arteries

what are the 3 superficial veins of UE?

cephalic, basilic, and antebrachial

What are the MAIN superficial veins of the upper extremity?

Cephalic (lateral aspect) and basilic veins (medial aspect)

What is the median cubital vein used for?

Venipuncture

Where do deep veins of the upper limb run?

Alongside arteries, as paired venae comitantes

Where are cubital lymph nodes located?

Medial epicondyle of humerus

What are the terminal branches of the brachial plexus?

Musculocutaneous, Axillary, Radial, Median, and Ulnar nerves

what nerve is the motor to the anterior compartment of arm (flexors of the shoulder and arm)?

musculocutaneous nerves (C5-7)

which nerve is the motor to most forearm anterior compartment (flexors and thenar muscles of the hand)?

median nerve (C5-8, T1)

what nerve is the motor for the medial forearm anterior compartment (flexors and most of the intrinsic muscles of the hand)?

ulnar nerve (C7-8, T1)

what nerve is the motor to the posterior compartment (extensors of the arm and forearm)?

radial nerve (C5-8, T1)

what does the pectoral group do?

moves the pectoral girdle

What nerve innervates the pectoralis major?

Medial and lateral pectoral nerves

what does the pectoralis major do?

ADDucts and medially rotates shoulder

what does the pectoralis minor do?

stabilizes the scapula

What nerve innervates the pectoralis minor?

pectoral nerve

what does the subclavius do?

provides some protection to underlying structures in event of clavicle fracture. (stabilizes clavicle)

what is the subclavius innervated by?

subclavian nerve

What nerve innervates the serratus anterior?

Long thoracic nerve

what does the serratus anterior do?

anchors the scapula to the posterior thorax, provides fixed point for movement of arm

What clinical finding occurs with long thoracic nerve injury?

Winging of the scapula

What nerve innervates the trapezius?

Spinal accessory nerve (CN XI)

what are the three actions of the trapezius?

elevates scapula, retracts scapula, and depresses scapula (lowers shoulders)

What nerve innervates the latissimus dorsi?

Thoracodorsal nerve

What nerve innervates the levator scapulae and rhomboids?

Dorsal scapular nerve

what does the latissimus dorsi do?

ADDucts humerus from over head position, acts directly on the glenohumeral joint

What innervates the levator scapulae?

dorsal scapular nerve

what does the levator scapulae do?

bilaterally extends neck and unilaterally side flexion of neck

what innervates the rhomboids?

dorsal scapular nerve

what do the rhomboids do?

retract and rotate scapula

What nerve innervates the deltoid?

Axillary nerve

What is the primary action of the deltoid?

Abduction of the shoulder (after the first 15 degrees)

What nerve innervates the teres major?

Lower subscapular nerve

What does the teres major do?

ADDucts and internally rotates the arm

What muscles make up the rotator cuff?

Supraspinatus, Infraspinatus, Teres minor, Subscapularis (SITS MUSCLES)

What are the actions of the rotator cuff muscles collectively?

Stabilize the glenohumeral joint

What nerve innervates the supraspinatus and infraspinatus?

Suprascapular nerve

What nerve innervates the teres minor?

Axillary nerve

What nerve roots form the axillary nerve?

C5-C6

What nerve roots form the musculocutaneous nerve?

C5-C7

What muscles are innervated by the musculocutaneous nerve?

Coracobrachialis, biceps brachii, and brachialis

What nerve provides sensation to the lateral forearm?

Lateral cutaneous nerve of the forearm (from musculocutaneous)

What nerve roots form the radial nerve?

C5-8, T1

What muscles are innervated by the radial nerve?

Extensors of the arm and forearm

What nerve roots form the median nerve?

C5-T1

What muscles are innervated by the median nerve?

Most forearm flexors except flexor carpi ulnaris and thenar muscles

What nerve is compressed in carpal tunnel syndrome?

Median nerve

C5-T1 roots form 3 trunks, what are they?

C5-6 form superior trunk, C7 middle trunk, C8-T1 inferior trunk

What nerve roots form the ulnar nerve?

C7-8, T1

What muscles are innervated by the ulnar nerve?

Flexor carpi ulnaris, medial half of flexor digitorum profundus, and most intrinsic hand muscles

What is the axilla?

A pyramidal passageway for neurovascular structures between neck and arm

What forms the anterior wall of the axilla?

Pectoralis major and minor

What forms the posterior wall of the axilla?

Latissimus dorsi and teres major

What forms the medial wall of the axilla?

Thoracic wall and serratus anterior

What forms the lateral wall of the axilla?

Humerus

Why are the axillary lymph nodes clinically significant?

They are common sites of metastasis from breast cancer