2. Nerve and blood supply to the upper limb

Question 1

Which artery supplies the upper limb?

Answer 1

Subclavian artery supplies the upper limb

Question 2

Where does subclavian artery pass through?

Answer 2

Passes through scalene triangle

Over first rib

Question 3

What does the subclavian artery divide into?

Answer 3

Divided into 3 parts by scalenus anterior:
1st Medial to muscle
2nd Behind muscle
3rd Lateral to muscle

Question 4

Thryocervical trunk

Answer 4

Thyrocervical trunk (to thyroid, cervical, scapular)
Contributes to scapular anastomosis

Question 5

Dorsal scapular artery

Answer 5

Dorsal scapular artery (from 2nd or 3rd part)

Contributes to scapular anastomosis

Question 6

Where does the subclavian artery end?

Answer 6

Ends at it crosses outer border of first rib

Becomes axillary artery

Question 7

What divides the axillary artery?

Answer 7

Divided into three parts by pectoralis minor:
1st Medial to muscle
2nd Behind muscle
3rd Lateral to muscle

Question 8

What is the axillary artery closely associated with?

Answer 8

First and second parts closely

associated with the brachial plexus

Question 9

Where does the axillary artery end and what does it become?

Answer 9

Ends at lower border of teres major

Becomes brachial artery

Question 10

What are some branches of the axillary artery?

Answer 10

Subscapular to scapular anastomosis

Ant/posterior circumflex humeral to neck/shaft of humerus

Question 11

What is significant about the surgical neck of the humerus

Answer 11

Risk of fracture, leading to trauma to the anterior/posterior circumflex humerus

Question 12

Brachial artery

Answer 12

Superficial throughout arm

Supplies flexors

Large branch - Profunda brachii artery

Contributes to anastomosis around elbow

Question 13

Profunda brachi artery

Answer 13

Large branch of brachial artery

Accompanies radial nerve in spiral groove

Question 14

Effect of fracture to humerus

Answer 14

trauma to profunda brachii artery

Question 15

Radial artery

Answer 15

Lateral side of forearm

Smaller of the two terminal branches

Covered by brachioradialis muscle

Forms deep palmer arch

Question 16

Radial artery in the hand

Answer 16

at wrist winds around to dorsum
through anatomical snuffbox
pierces first dorsal interosseous muscle

Question 17

Ulnar artery

Answer 17

Medial side of forearm

Covered by flexor carpi ulnaris muscle

Deep branch
- Common interosseous artery (which heads to interosseous membrane)

Forms superficial palmar arch

Question 18

What artery forms the deep palmer arch?

Answer 18

the radial artery

Question 19

What artery forms the superficial palmer arch?

Answer 19

ulnar artery

Question 20

Venous return

Answer 20

Considerably variable
Drains into axillary vein into subclavian vein
Deep and superficial veins

Question 21

Deep veins

Answer 21

Paired veins

Venae comitantes

Question 22

Superficial veins

Answer 22

Cephalic in lateral forearm
Basilic in medial forearm
From dorsal venous arch

Question 23

Lymphatic drainage

Answer 23

Relatively few lymph nodes in upper limb

Lymph drains to axillary nodes

Question 24

brachial plexus

Answer 24

Nerve supply to the upper limb

Carries motor, sensory and sympathetic axons

Produces mixed nerves
(i.e. contains axons from multiple spinal nerves)

- Important to supply large muscle groups

Question 25

Brachial plexus overview

Answer 25

divided into roots, trunks, division and cords

Question 26

Brachial plexus roots

Answer 26

Roots are ventral primary rami of C5 – T1

Dorsal scapular nerve (to the rhomboids and levator scapulae)
Long thoracic nerve (to serratus anterior)

Question 27

Motor innervation

Answer 27

Motor axons within each root innervate a different functional group of muscles (myotomes)

C5 Shoulder abduction and adduction

C6/C7 Elbow flexion and extension

C7/C8 Wrist flexion and extension

C8/T1 Movement of the digits

Question 28

Brachial plexus trunks

Answer 28

Roots form trunks

Trunks pass through scalene triangle

Question 29

Divisions of brachial trunks

Answer 29

Each trunk divides into anterior and posterior divisions

• Anterior: Axons to flexor compartments
  [Forms lateral and medial cords]
• Posterior: Axons to extensor compartments
  [Forms posterior cord]

Question 30

Cords of brachial plexus

Answer 30

Under pectoralis minor

Cords named in relation to axillary artery

Question 31

Lateral cords of brachial plexus

Answer 31

Terminates as:
Musculocutaneous nerve
Lateral part of median nerve

Question 32

What cords form the median nerve?

Answer 32

Lateral and medial cords

Question 33

Medial cord

Answer 33

Terminates as:
Medial part of median nerve
Ulnar nerve

Question 34

What cords form the median nerve?

Answer 34

Lateral and medial cords

Question 35

Medial nerve

Answer 35

Motor – Anterior forearm and lateral hand

Sensory – Lateral palm hand, d1,2, 3 + half d4

Question 36

Ulnar nerve

Answer 36

Motor – Medial side anterior forearm and hand

Sensory – Medial hand + half d4 + d5

Question 37

Posterior cord

Answer 37

Terminates as:
Radial nerve
Axillary nerve

Question 38

Radial nerve

Answer 38

Motor – posterior arm and posterior forearm

Sensory – posterior arm and posterior forearm + lateral dorsum hand

Question 39

Axillary nerve

Answer 39

Motor – deltoid and teres minor

Sensory – badge area of arm

Question 40

Terminal branches of brachial plexus

Answer 40

musculocuteaneous nerve
axillary nerve
median nerve
radial nerve
ulnar nerve

Question 41

Upper limb dermatomes

Answer 41

An individual area of skin innervated by a single spinal nerve”

Established during development

Lots of overlap/variation

Clinical: Altered sensation in the region of a dermatome indicates damage to specific spinal nerve of spinal cord segment (i.e. proximal nerve injury)

Question 42

Cutaneous innervation by terminal branches

Answer 42

Map looks different to dermatome map
Terminal branches contain axons from multiple spinal nerve

Clinical: Altered sensation in one of the areas indicates damage to a more distal nerve segment (i.e. distal nerve injury)

Question 43

What forms the scalene triangle?

Answer 43

1st rib, scalenus medius, scalenus anterior

Question 44

Branches of subclavian artery

Answer 44

Vertebral artery (1st part)
Thyrocervical trunk (to thyroid, cervical, scapular)
Dorsal scapular artery (from 2nd or 3rd parts)

Question 45

What does the brachial artery divide into and where?

Answer 45

Divides in cubital fossa into radial artery and ulnar artery