(Completed) Upper Limb: Nerve Supply

based on 2027 Trans

The dermatome maps we use today are based on which developmental aspect of the limbs?

a) The medial rotation of the upper limbs during development.

b) The lateral protrusion of the trunk with the first digit directed superiorly.

c) The development of the axial skeleton.

d) The formation of the neural tube.

B. The lateral protrusion of the trunk with the first digit directed superiorly.

Name the two primary plexuses that contribute to the dermatome maps.

Brachial Plexus

Cervical Plexus

Determine the Cutaneous innervation of the Hand. (Options: Ulnar Nerve, Median Nerve & Radial Nerve)

Anterior Surface

Pink and ½ of Ring finger - Ulnar

Rest of fingers - Median

Small portion of base of thumb - radial

Posterior Surface

Pink and ½ of Ring finger - Ulnar

distal phalanges of thumb, index, middle and ½ ring - Median

remaining space on the posterior - Radial

The brachial plexus is formed by the union of the Anterior rami of 4 cervical and 1 thoracic (C5,6,7,8 & T1). It is composed of Roots, Trunks, Divisions, Cords and Terminal Branches. Give the 5 Roots of the Brachial Plexus.

4 cervical and 1 thoracic (C5,6,7,8 & T1)

True or False. All posterior divisions will join to become the posterior cord.

True.

True or False. All anterior divisions will join to become the anterior cord.

False! All anterior divisions will join and form the Lateral cord.

Cords are based on its location in relation to the ____ artery.

Axillary

The Lateral cord will give rise to which nerve?

Musculocutaneous n.

The Posterior cord will give rise to the which nerves?

Axillary & Radial n.

The Medial cord will give rise to which nerves?

ulnar & medial n.

What union forms the inferior trunk of brachial plexus?

C8 and T1

What union forms the superior trunk?

C 5 and 6

The Posterior cord is formed by ______ divisions of trunks. (Anterior or posterior)

Posterior

The lateral and Medial cord are formed by ___ divisions. (Anterior or posterior)

Anterior

What is the reference structure for the Spinal cords?

Axillary ARTERY

The posterior cord gives off which 2 nerves?

Axillary nerve and Radial nerve

The Lateral cord will branch into which nerve, as well as join the ____ cord.

Musculocutaneous nerve and join Medial Cord

The medial cord will form which 2 nerves?

Ulnar nerve and Medial cutaneous

What is the Nerve roots of the Axillary Nerve

C5 and 6

What 2 muscles does the Axillary nerve innervate?

Deltoid ms. & Teres minor ms.

Which nerve provides sensory innervation to the skin over the shoulder?

Axillary nerve

Which 2 Nerves receives from all 5 nerve roots?

All of the nerves coming from the Posterior cord. Axillary and Radial nerve

Which nerve passes POSTERIOR to the MEDIAL EPICONDYLE of the humerus.

Ulnar nerve

True or false. The Ulnar nerve passes anterior to the medial epicondyle of the humerus.

FALSE! Ulnar nerve? Posterior!

Damage to ____ nerve may result in Claw Hand Deformity.

ULNAR

Which nerve innervates the palmar aspect of the pointer finger

Median

Loss of flexion of the Proximal and distal interphalangeal joints or “Benediction Injury” is often due to ___ nerve injury?

Median Nerve

Which cord does the musculocutaneous nerve originate from?

Lateral cord

The musculocutanous nerve innervates which 3 muscles of the anterior arm?

Biceps brachii

Coracobrachialis

Brachialis

The musculocutaneous nerve pieces WHICH MUSCLE?

Coracobrachialis ms.

The anterior Compartment of ARM is innervated by which nerve?

The posterior Compartment of ARM is innervated by which nerve?

Anterior compartment - Musculocutaneous Nerve

Posterior Compartment - Radial Nerve

The anterior Compartment of FOREARM is innervated by which nerve?

The posterior Compartment of FOREARM is innervated by which nerve?

Anterior of Forearm = Median nerve

Posterior Forearm = Radial nerve

What nerve innervates the Flexor carpi ulnaris & Ulnar half of Flexor digitorum profundus?

Ulnar nerve

Injury to which nerve causes WINGING OF SCAPULA? (*slam table like philip)

Long Thoracic Nerve!

What is the affected muscle when there is Winging of scapula?

Serratus Anterior (Boxer’s Muscle")

Erb’s Palsy or Erb’s Duchenne Palsy or “Waiter’s tip” position is due to Injury of which Trunk of the brachial plexus?

Superior Trunk. → Median, Musculocutanous, Axillary and Suprascapular Nerves

Weakening of forearm and hand muscles (e.g. claw hand) is due to damage to which trunk of the brachial plexus?

Inferior Trunk

Injury to the radial nerve is due to injury of which Cord?

Posterior cord

Deltoid atrophy or instability of muscles around the Scapula may be due to what nerve injury?

Axillary Nerve

Thenar Atrophy may signify what nerve injury?

Median nerve

Carpal Tunnel syndrome can be caused by prolonged compression of which nerve?

Median Nerve

The Hypothenar compartment is supplied by which nerve?

Ulnar

Wrist drop is often due to injury of which nerve?

Radial nerve

Cannot do “OK” sign is due to which nerve injury?

A. Radial

B. Anterior Interosseous Nerve injury

C. Median nerve

B.