Nerves of the Upper Limb

Question 1

Describe the structure of the brachial plexus

Answer 1

It follows a pattern of :

Roots, Trunks, Divisions, Cords, Branches

Question 2

What is the brachial plexus ?

Answer 2

The entirety of the motor and sensory nerve supply to the upper limb.

Sensory and motor derive from the ventral rami of C5-T1

Question 3

Plexus

Answer 3

An intricate network or arrangement

Question 4

Dermatome

Answer 4

An areas of skin innervated by a spinal segment
Variation and overlap

Question 5

C6

Answer 5

Thumb

Question 6

C7

Answer 6

Middle finger

Question 7

C8

Answer 7

Little finger

Question 8

T10

Answer 8

Belly button

Question 9

T4

Answer 9

Nipples

Question 10

Myotome

Answer 10

A group of muscles innervated by a single spinal segment

Question 11

Where is the brachial plexus located ?

Answer 11

In the root of the neck.
Extending from the ventral rami of C5-T1

Question 12

State the roots of the brachial plexus

Answer 12

Anterior Rami
C5
C6
C7
C8
T1

Question 13

State the trunks of the brachial plexus

Answer 13

C5+6 - Superior Trunk
C7- Middle Trunk
C8+T1 - Inferior Trunk

These are found before the clavicle (usually)

Question 14

State the divisions of the brachial plexus

Answer 14

Superior Trunk : Anterior division + Anterior division to join middle posterior

Middle Trunk : Posterior division + Posterior division to join superior anterior + Posterior division to join inferior anterior

Inferior Trunk : Anterior Division

Question 15

State the cords of the brachial plexus

Answer 15

Anterior division : Lateral cord
Posterior division : Posterior cord
Anterior division Medial cord

Question 16

State the branches of the brachial plexus

Answer 16

Branches are called “Terminal Nerves”

Musculocutaneous Nerve
(Radial nerve)
Median Nerve
(Axillary nerve)
Ulnar Nerve

Question 17

Function of the Musculocutaneous nerve

Answer 17

Supplies :

Arm, anterior compartment muscles

Lateral cutaneous nerve of the forearm

Question 18

Function of the Median nerve

Answer 18

Supplies :

Forearm, Anterior compartment muscles
Hand, thenar muscles

1/2 skin of palm

Question 19

Function of the Ulnar nerve

Answer 19

Supplies :

Forearm, 1 1/2 muscles
Hand, small muscles

1/2 skin of hand

Question 20

Function of the Radial nerve

Answer 20

Supplies :

Arm, Posterior compartment muscles

Forearm, posterolateral skin
Hand, dorsal skin

Question 21

Function of the axillary nerve

Answer 21

Supplies :

Deltoid and Teres Minor muscles

Skin of supra-lateral arm

Question 22

Musculocutaneous nerve

Answer 22

C5-7

Question 23

Axillary nerve

Answer 23

C5,6

Question 24

Median nerve

Answer 24

C6-T1

Question 25

Radial nerve

Answer 25

C5-T1

Question 26

Ulnar nerve

Answer 26

C(7), 8, T1

Question 27

Phrenic nerve

Answer 27

Nor part of the brachial plexus Supplies the diaphragm C3,4,5

Question 28

1st intercostal nerve

Answer 28

T1

Question 29

Long thoracic nerve

Answer 29

C5,6,7 Supplies serratus anterior

Question 30

Clinical relevance of long thoracic nerve

Answer 30

When doing chest drains you may damage the long thoracic nerve in the chest wall

Question 31

Dorsal scapular nerve

Answer 31

Supplies the rhomboids (sometimes levator scapulae)

Question 32

Suprascapular nerve

Answer 32

Goes to the suprascapular notch Suprascapular foramen Artery above, nerve below

Question 33

Subclavius nerve

Answer 33

Small nerve that anchors and stabilises clavicle

Question 34

Lateral pectoral nerve

Answer 34

Supplies pectoralis major

Question 35

Lower subscapular Thoracodorsal Upper subscapular

Answer 35

Supplies : subscapularis Teres major Latissimus dorsi

Question 36

Medial ante brachial cutaneous Medial brachial cutaneous Medial pectoral

Answer 36

Cutaneous - medial forearm pectoral - pectorals major and minor

Question 37

Intercostal brachial nerve

Answer 37

T2 Cutaneous in axilla

Question 38

Upper Brachial plexus injury

Answer 38

Erb's palsy - Affects Roots C5,6 - (waiters tip sign)

Question 39

Lower Brachial plexus injury

Answer 39

Klumpkey's palsy - Affects Roots C8, T1 - (claw hand - intrinsic hand muscles)