Nerves of the Upper Limb Flashcards
Describe the structure of the brachial plexus
It follows a pattern of :
Roots, Trunks, Divisions, Cords, Branches
What is the brachial plexus ?
The entirety of the motor and sensory nerve supply to the upper limb.
Sensory and motor derive from the ventral rami of C5-T1
Plexus
An intricate network or arrangement
Dermatome
An areas of skin innervated by a spinal segment
Variation and overlap
C6
Thumb
C7
Middle finger
C8
Little finger
T10
Belly button
T4
Nipples
Myotome
A group of muscles innervated by a single spinal segment
Where is the brachial plexus located ?
In the root of the neck.
Extending from the ventral rami of C5-T1
State the roots of the brachial plexus
Anterior Rami
C5
C6
C7
C8
T1
State the trunks of the brachial plexus
C5+6 - Superior Trunk
C7- Middle Trunk
C8+T1 - Inferior Trunk
These are found before the clavicle (usually)
State the divisions of the brachial plexus
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
State the cords of the brachial plexus
Anterior division : Lateral cord
Posterior division : Posterior cord
Anterior division Medial cord
State the branches of the brachial plexus
Branches are called “Terminal Nerves”
Musculocutaneous Nerve
(Radial nerve)
Median Nerve
(Axillary nerve)
Ulnar Nerve
Function of the Musculocutaneous nerve
Supplies :
Arm, anterior compartment muscles
Lateral cutaneous nerve of the forearm
Function of the Median nerve
Supplies :
Forearm, Anterior compartment muscles
Hand, thenar muscles
1/2 skin of palm
Function of the Ulnar nerve
Supplies :
Forearm, 1 1/2 muscles
Hand, small muscles
1/2 skin of hand
Function of the Radial nerve
Supplies :
Arm, Posterior compartment muscles
Forearm, posterolateral skin
Hand, dorsal skin
Function of the axillary nerve
Supplies :
Deltoid and Teres Minor muscles
Skin of supra-lateral arm
Musculocutaneous nerve
C5-7
Axillary nerve
C5,6
Median nerve
C6-T1
Radial nerve
C5-T1
Ulnar nerve
C(7), 8, T1
Phrenic nerve
Nor part of the brachial plexus
Supplies the diaphragm
C3,4,5
1st intercostal nerve
T1
Long thoracic nerve
C5,6,7
Supplies serratus anterior
Clinical relevance of long thoracic nerve
When doing chest drains you may damage the long thoracic nerve in the chest wall
Dorsal scapular nerve
Supplies the rhomboids (sometimes levator scapulae)
Suprascapular nerve
Goes to the suprascapular notch
Suprascapular foramen
Artery above, nerve below
Subclavius nerve
Small nerve that anchors and stabilises clavicle
Lateral pectoral nerve
Supplies pectoralis major
Lower subscapular
Thoracodorsal
Upper subscapular
Supplies :
subscapularis
Teres major
Latissimus dorsi
Medial ante brachial cutaneous
Medial brachial cutaneous
Medial pectoral
Cutaneous - medial forearm
pectoral - pectorals major and minor
Intercostal brachial nerve
T2
Cutaneous in axilla
Upper Brachial plexus injury
Erb’s palsy
- Affects Roots C5,6
- (waiters tip sign)
Lower Brachial plexus injury
Klumpkey’s palsy
- Affects Roots C8, T1
- (claw hand - intrinsic hand muscles)
