Peripheral Mononeuropathy - The Brachial Plexus

Question 1

Parts of the Brachial Plexus (5).

Answer 1

RTDCB (Read That Damn Cadaver Book) :

1. R - Roots.
2. T - Trunks.
3. D - Divisions.
4. C - Cords.
5. B - Branches.

Question 2

Spinal Nerves and Brachial Plexus.

Answer 2

1. At each vertebral level, paired spinal nerves arise and leave the spinal cord via the intervertebral foramina.
2. Divides into anterior and posterior ramus.

Question 3

What are the Roots of the Brachial Plexus?

Answer 3

Anterior Rami of Spinal Nerves - C5, C6, C7, C8, T1.

Question 4

What do the Roots pass through?

Answer 4

Between anterior and medial Scalene muscles to enter the base of the neck.

Question 5

What are the Trunks of the Brachial Plexus?

Answer 5

1. Superior : C5, C6.
2. Middle - C7.
3. Inferior : C8, T1.

Question 6

What do the Trunks pass through?

Answer 6

Transverse laterally to cross the Posterior Triangle of the Neck.

Question 7

What are the Divisions of the Brachial Plexus?

Answer 7

Branches of each trunk - one branch moves anterior and one branch move posterior for each trunk.

Question 8

What do the Divisions pass through?

Answer 8

Pass into the axilla.

Question 9

What are the Cords of the Brachial Plexus? (3).

Answer 9

1. Lateral Cord - Anterior Superior and Anterior Middle Division.
2. Posterior Cord : All 3 Posterior Divisons.
3. Medial Cord : Anterior Inferior Divison.

Question 10

What are the Branches of the Brachial Plexus? (5)

Answer 10

1. Musculocutaneous Nerve.
2. Axillary Nerve.
3. Radial Nerve.
4. Median Nerve.
5. Ulnar Nerve.

Question 11

Roots of Musculocutaneous Nerve.

Answer 11

C5, C6, C7.

Question 12

Motor Functions of Musculocutaneous Nerve.

Answer 12

1. Biceps Brachii.
2. Brachialis.
3. Coracobrachialis.

Question 13

Sensory Functions of Musculocutaneous Nerve.

Answer 13

1. Lateral Half of Anterior Forearm.

2. Small Lateral Portion of Posterior Forearm.

Question 14

Roots of Axillary Nerve.

Answer 14

C5, C6.

Question 15

Motor Functions of Axillary Nerve.

Answer 15

1. Deltoid.

2. Teres Minor.

Question 16

Sensory Functions of Axillary Nerve.

Answer 16

Regimental Badge - Inferior Region of Deltoid.

Question 17

Injury to Axillary Nerve.

Answer 17

1. Fracture to Humeral Surgical Neck.
2. Shoulder Dislocation.
3. Iatrogenic - Shoulder Surgery.

Question 18

Roots of Median Nerve.

Answer 18

C6, C7, C8, T1.

Question 19

Motor Functions of Median Nerve.

Answer 19

1. Forearm Flexor Muscles.
2. Thenar Muscles.
3. 2 Lateral Lumbricals of Index and Middle Fingers.

Question 20

Sensory Functions of Median nerve.

Answer 20

1. Lateral Palm.

2. Lateral 3.5 Fingers on Palmar Hand.

Question 21

Roots of Radial Nerve.

Answer 21

C5, C6, C7, C8, T1.

Question 22

Motor Functions of Radial Nerve.

Answer 22

1. Triceps Brachii.

2. Posterior Forearm : Extensors of Hand and Wrist.

Question 23

Sensory Functions of Radial Nerve.

Answer 23

1. Posterior Arm.
2. Posterior Forearm.
3. Posterolateral Hand - Lateral 3.5 Fingers on Dorsal Hand.

Question 24

Roots of Ulnar Nerve.

Answer 24

C8, T1.

Question 25

Motor Functions of Ulnar Nerve.

Answer 25

1. All Muscles of Hand except Thenar and 2 Lateral Lumbricals.
2. Flexor Carpi Ulnaris.
3. Medial Half of Flexor Digitorum Profundus.

Question 26

Sensory Functions of Ulnar Nerve.

Answer 26

Anterior and Posterior Surface of Medial 1.5 Fingers.

Question 27

What is Erb’s Palsy?

Answer 27

Upper Brachial Plexus Injury (injury to upper roots : C5, C6) resulting from a stretching injury during a difficult vaginal delivery.

Question 28

Clinical Features of Erb’s Palsy.

Answer 28

1. Waiter’s Tip : Weakness in Pectoralis Major, Biceps Brachii, Wrist Flexors.

Question 29

What is Klumpke’s Palsy?

Answer 29

Lower Brachial Plexus Injury (injury to lower roots : C8, T1) also associated with difficult vaginal delivery.

Question 30

Clinical Features of Klumpke’s Injury.

Answer 30

Clawed Hand (Paralysis of Lumbricals).