The document provides an overview of the anatomy of the upper extremity. It describes the 32 bones that make up the skeleton of the upper limb, including the scapula and clavicle that form the pectoral girdle and the 30 bones that comprise the free part of the upper limb. It also details the major joints of the upper extremity, including the glenohumeral joint, elbow joint, and wrist joints. Additionally, it outlines the muscles of the upper limb, their origins, insertions, and innervation by the brachial plexus. The brachial plexus and its formation from spinal nerve roots C5-T1 is also summarized.

1. The Upper Extremity
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Dr. Emad Abu Alrub MD PhD
Dr. Emad Abu Alrub MD PhD
AAUP- Medicine

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4. Osteology/ Bones
Skeleton of the Upper Limb
• Each upper limb has 32 bones
• Two separate regions
1. The pectoral (shoulder) girdle (2 bones)
2. The free part (30 bones)
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6. Upper Limb
• The pectoral girdle consists of two
bones, the scapula posteriorly and
the clavicle anteriorly.
• The free part has 30 bones
 1 humerus (arm)
 1 ulna (forearm)
 1 radius (forearm)
 8 carpals (wrist)
 19 metacarpal and phalanges (hand)
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9. • Pectoral girdle
– Glenoid cavity
• Allows for mobility
– Attachments
• Upper extremity:
– Arm
• humerus
– Forearm
• Radius, ulna (interosseous membrane)
– Hand
• Carpals, metacarpals, phalanges
• Review bones and landmarks studied in lab!!!
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10. Joints of Upper Extremity
• Sternoclavicular
– Synovial-saddle
– Diarthrosis
• Acromioclavicular
– Synovial-plane
– Diarthrosis
• Glenohumeral joint
– Synovial-ball&socket
– Diarthrosis
– Many ligaments
– Muscle reinforcement
– Great Mobility
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11. Joints of the Upper
Extremity
• Elbow Joint
– Synovial – hinge
– Diarthrosis
• Articulations
– Humerus & Ulna
– Humerus & Radius
• Many Ligaments
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12. • Proximal Radioulnar joint
– Synovial - pivot
– Diarthrosis
• Distal Radioulnar joint
– Synovial – pivot
– Diarthrosis
• Allows pronation and
supination of forearm
Joints of the Upper Extremity
Interosseous
membrane
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13. Joints of the Upper Extremity
• Radiocarpal joint
– Synovial-condyloid
– Distal radius with proximal row of
carpals
• Intercarpal joints
– Synovial-plane
• Carpal-metacarpal (2-5)
– Synovial-plane
• Trapezium-metacarpal 1
– Synovial-saddle
• Metacarpal-phalangeal
– Synovial-condyloid
• Interphalangeal
– Synovial-hinge
• ALL DIARTHROSES
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Dinner fork deformity

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Humerus fractures

16. Review of Naming…..
• What do the following names
TELL you about the muscle?
– Naming
• Flexor carpi ulnaris
• Flexor digitorum superficialis
• Flexor pollicis longus
• Pronator quadratus
• Extensor carpi radialis brevis
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17. Scapula Muscles
• If the origin is on the
scapula – moves the arm
– Subscapularis
– Supraspinatus
– Infraspinatus
– Teres Minor
– Teres Major
– Latissimus Dorsi (partial
attachment) (inconstant)
– Coracobrachialis
Rotator
Cuff
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18. Scapula Muscles
• If the insertion is on the
scapula – moves the
scapula
– Rhomboids
– Trapezius
– Pectoralis Minor
– Serratus Ventralis
– Levator Scapulae
Use location of Insertion to
determine movement!!
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19. Innervation of Muscles Moving
Arm
Muscle Innervation
Subscapularis
Teres Major
Subscapular N.
Infraspinatus
Supraspinatus
Suprascapular N.
Teres Minor Axillary N.
Coracobrachialis Musculocutaneous N.
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20. Arm Muscles
• Arm Compartments
– Anterior Compartment
(3 muscles)
• Flexors of forearm and
arm
– Posterior Compartment
(1 muscle)
• Extensor of forearm and
arm
Remember: If you cross the shoulder, you
move the arm; if you cross the elbow, you
move the forearm
Extensor Flexors
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21. Arm Muscles
• Anterior compartment
– Brachialis
– Coracobrachialis
– Biceps brachii
• Long head
• Short head
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22. Arm Muscles
• Posterior compartment
– Triceps brachii
• Long head
• Medial head
• Lateral head
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23. Muscles of Arm
Muscle Origin Insertion Action Innerv
Anterior
Brachialis Ant shaft , distal humerus Coronoid process
/ulnar tuberosity
(ulna)
Flex
forearm
Musculo-
cutaneous
Biceps Brachii Long: supraglenoid
tubercle (scapula)
Short: coracoid proc
(scapula)
Radial Tuberosity
(radius)
Flex
forearm,
Supination
Musculo-
cutaneous
Coracobrachialis Coracoid proc (scapula) Medial surface
midshaft
(humerus)
Flex arm,
Adduct arm
Musculo-
cutaneous
Posterior
Triceps Brachii Long: Infraglenoid tubercle
(scapula)
Medial: Posterior Shaft
(middle humerus)
Lateral: Posterior Shaft
(proximal humerus)
Common tendon
to olecranon
(ulna)
Extend
forearm
Radial
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24. Forearm Muscles
• Cross elbow, wrist and finger
joints
• Movement of hand and fingers
• Proximally are fleshy
• Distally have long tendons
• Flexor and extensor retinacula
– “wristbands”
– Keep tendons from jumping
outwards when tensed
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25. Forearm Muscles
• Anterior compartment
– Superficial, Intermediate and Deep layers
– Flexors of hand and fingers
– Most flexors have common origin on
medial epicondyle
– Contains 2 pronator muscles
• Posterior compartment
– Superficial and Deep layers
– Extensors of hand and fingers
– Most extensors have common origin on
lateral epicondyle
– Contains a supinator muscle
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26. Anterior Compartment of Forearm
Muscles Nerves
– Superficial
• Flexor digitorum superficialis Median
• Flexor carpi radialis Median
• Pronator teres Median
• Palmaris longus Median
• Flexor carpi ulnaris Ulnar
– Deep
• Pronator quadratus Median
• Flexor pollicis longus Median
• Flexor digitorum profundus Ulnar (med 1/2)
Median (lat 1/2)
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27. Posterior Compartment of Forearm
Muscles Nerves
– Superficial
• Brachioradialis Radial
• Anconeus Radial
• Extensor carpi radialis longus & brevis Radial
• Extensor digitorum Radial
• Extensor carpi ulnaris Radial
• Extensor digiti minimi Radial
– Deep
• Supinator Radial
• Abductor pollicis longus Radial
• Extensor pollicis longus + brevis Radial
• Extensor indicus Radial
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28. Hand Bones
• Carpus (8)
– “True” wrist
– Distal to radius/ulna
• Metacarpus (5)
– Distal to carpus
• Phalanges (14)
– Distal to metacarpus
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29. Intrinsic Muscles of the Hand
Muscle Nerve
• Pinky = Hypothenar muscles
– All digiti minimi Ulnar
(Flexor, Abductor, Opponens)
• Thumb = Thenar muscles
– Abductor pollicis brevis Median
– Flexor pollicis brevis Median
– Opponens pollicis Median
– Adductor pollicis Ulnar
• Other Intrinsic Muscles
– Palmar + Dorsal Interossei Ulnar
– Lumbricals Median,
Ulnar
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30. Blood Supply - Arteries
• Subclavian (neck)
• Axillary (armpit)
– Subscapular
– Circumflex humeral arteries
• Brachial (arm)
– Deep brachial
• Radial (forearm)
• Ulnar (forearm)
– Common Interosseous
• Superficial & Deep Palmar
arches
– Digital
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31. Blood Supply - Veins
• Deep veins
– Deep palmar venous arches
– Radial - forearm
– Ulnar - forearm
– Brachial – arm/elbow
– Axillary – axilla
– Subclavian - neck
• Superficial Veins
– Digital
– Superficial palmar venous arches
– Median – forearm
– Median cubital – elbow
• Blood draws!!
– Cephalic – arm/forearm
– Basilic – arm/forearm
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33. Axilla
• Armpit!!
• Boundaries
– Ventral
• Pectoral muscles
– Dorsal
• Latissimus dorsi, teres major,
subscapularis
– Medial
• Serratus ventralis
– Lateral
• Intertubercular (Bicipital) groove of
humerus
• Contents
– axillary lymph nodes, axillary
vessels, brachial plexus
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34. Surface Anatomy of Arm
• Cephalic Vein
• Biceps brachii
• Triceps brachii
• Olecrenon Process
• Medial Epicondyle
• Lateral Epicondyle
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35. Surface Anatomy of Elbow
• Cubital Fossa
– Anterior surface elbow
– Contents
• Median Cubital Vein
• Brachial Artery
• Median Nerve
– Boundaries
• Medial= Pronator teres
• Lateral= Brachioradialis
• Superior= Line between epicondyles
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36. Surface Anatomy of Hand
• Carpal Tunnel
– Carpals concave anteriorly
– Carpal ligament covers it
– Contains: long tendons, Median
nerve
– Inflammation of tendons =
compression of Median nerve
• Anatomical Snuffbox
– Lateral = E.pollicis brevis
– Medial = E. pollicis longus
– Floor = scaphoid, styloid of radius
– Contains Radial Artery (pulse)
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37. Brachial Plexus
• Nerve plexus
• Lies partly in neck and partly in
axilla
• Gives rise to almost all nerves
that supply upper limb
• Formed by intermixing of ventral
rami of spinal nerves C5-C8 and T1
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38. Brachial Plexus
• Really Tired? Drink Coffee Buddy!
• R = RAMI (ventral) (5)
• T = TRUNKS (3)
• D = DIVISIONS (2)
• C = CORDS (3)
• B = BRANCHES (Many!!)
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39. Lateral Cord
• Musculocutaneous nerve
– Off lateral cord
– Course:
• Anterior arm
• Becomes cutaneous and gives skin sensation to lateral forearm
– Innervates:
• Corocobrachialis (motor)
• Biceps brachii (motor)
• Brachialis (motor)
• Skin distal to the elbow (sensory)
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40. Medial Cord
• Ulnar nerve
– Course:
• Comes off medial cord
• Descends along medial side of arm
• Passes posterior to medial epicondyle
• Follows the ulna
• Superficial to carpal tunnel into hand
• Branches to supply intrinsics and skin
– Innervates:
• Flexor carpi ulnaris (motor)
• Flexor digitorum profundus (motor)
• Most intrinsic hand muscles (motor)
• Dorsal branch supplies skin of medial 2/3 of hand (sensory)
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41. Both Medial and Lateral Cords
• Median nerve
– Course:
• Middle of brachial plexus (from lateral and medial cords)
• Does not branch in arm
• Distal to elbow provides many branches to most forearm flexors
• Passes through carpal tunnel to hand to lateral palmar intrinsics
– Innervates:
• Anterior forearm (motor)
– Most flexors, some intrinsics (thumb)
• 2/3 Lateral palm (sensory)
• Dorsum of fingers 2 and 3 (sensory)
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42. Posterior Cord
• Radial nerve
– Largest branch of brachial plexus
– Comes from posterior cord
– Course:
• Through arm
• Around humerus
• Around lateral epicondyle (then divides)
– Innervates:
• Posterior muscles of arm and forearm
– Triceps brachii, anconeus, brachioradialis
– Divides in forearm:
• Superficial
– Skin of arm and dorsolateral surface of hand
• Deep
– Supinator & Extensor muscles of forearm (eg ext. carpi radialis L + B)
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43. Posterior Cord (continued)
• Axillary nerve
– Branches off posterior cord
– Course:
• Runs posterior to humerus
• Runs with caudal humeral circumflex artery
– Innervates:
• Deltoid and teres minor (motor)
• Capsule of shoulder, skin of shoulder (sensory)
• Subscapular nerve
– Innervates:
• Subscapularis, Teres major
• Thoracodorsal nerve
– Course:
• Runs with thoracodorsal artery and vein
– Innervates:
• Latissimus dorsi
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44. Nerve Damage
• Ulnar nerve
– “Claw hand”
• Inability to extend fingers at
interphalangeal joints, results in permanent
flexion of hand = claw
• Median nerve
– “Ape hand”
• Inability to oppose thumb
• Radial nerve
– “Wrist drop”
– Inability to extend the hand, inability to fully
extend forearm
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46. Thank you!
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