Upper Limb: Brachial Plexus

Question 1

Which ventral rami unite to form the “typical” branches?

Answer 1

C5-T1

Question 2

Which ventral rami unite to form the inferior trunk of the brachial plexus?

A. C5-C6
B. C6-C7
C. C8-T1

Answer 2

C

Question 3

True or False: All the trunks of the brachial plexus will give rise to anterior and posterior divisions.

Answer 3

True

Question 4

Which divisions unite to form the lateral cord of the brachial plexus?

A. Posterior divisions of the superior and inferior trunks
B. Anterior divisions of the superior and middle trunks
C. Anterior divisions of the middle and inferior trunks
D. Posterior divisions of the middle and inferior trunks

Answer 4

B

Question 5

Which of the following nerves is considered a supraclavicular branch of the brachial plexus? Select all that apply.

Dorsal scapular nevre
Radial nerve
Suprascapular nerve
Long thoracic nerve
Musculocutaneous nerve
Axillary nerve

Answer 5

Dorsal scapular nerve
Suprascapular nerve
Long thoracic nerve

Question 6

Which of the following nerves are considered terminal branches of the brachial plexus? Select all that apply.

Lateral pectoral nerve
Upper subscapular nerve
Axillary nerve
Musculocutaneous nerve
Median nerve
Medial brachial cutaneous nerve

Answer 6

Axillary nerve
Musculocutaneous nerve
Median nerve

Question 7

Which of the following spaces is considered a space of the thoracic outlet? Select all that apply.

Quadrangular space
Scalene triangle
Triangular space
Costoclavicular space
Subpectoral space

Answer 7

Scalene triangle
Costoclavicular space
Subpectoral space

Question 8

Which structures form the scalene triangle?

Answer 8

Anterior scalene, middle scalene, 1st rib

Question 9

The __________ branches of the brachial plexus arise from the cords and supply muscles of the arm, forearm, and hand region.

Answer 9

Infraclavicular

Question 10

The __________ branches of the brachial plexus arise from ventral rami of spinal nerves C5 through T1 and the superior trunk, and supply several muscles of the shoulder region.

Answer 10

Supraclavicular

Question 11

What does prefixed brachial plexus mean?

Answer 11

Large contribution from C4, less or no contribution from T1

Question 12

What does post-fixed brachial plexus mean?

Answer 12

Large contribution from T2, less or no contribution from C5

Question 13

What two supraclavicular branches arise from the roots of spinal nerves?

Answer 13

Dorsal scapular nerve (C5)
Long thoracic nerve (C5, C6, C7)

Question 14

What are the three trunks of the brachial plexus?

Answer 14

Superior, middle, inferior

Question 15

What rami form each trunk of the brachial plexus?

Answer 15

Superior: C5, C6
Middle: C7
Inferior: C8, T1

Question 16

What two supraclavicular branches arise from the superior trunk? What spinal nerves do they both originate from?

Answer 16

Suprascapular nerve
Nerve to subclavius
Both arise from C5, C6

Question 17

What divions form the cords of the brachial plexus?

Answer 17

Lateral cord: Anterior divisions of superior and middle trunks
Medial cord: Anterior division of inferior trunk
Posterior cord: Posterior divisions of superior, middle, and inferior trunks

Question 18

Where are the cords of the brachial plexus in relation to the axillary artery?

Answer 18

They are NAMED according to their directional relation!

Lateral cord is lateral
Medial cord is medial
Posterior cord is posterior

Question 19

What three nerves arise from the posterior cord? What two terminal branches?

Answer 19

Upper subscapular nerve
Lower subscapular nerve
Thoracodorsal nerve

Terminal branches: axillary nerve, radial nerve

Question 20

What nerve arises from the lateral cord? What two terminal branches?

Answer 20

Lateral pectoral nerve

Terminal branches: Musculocutaneous, contribution to median nerve

Question 21

If the posterior cord supplies muscles of the posterior compartment and posterior aspects of the upper limb, which cord supplies the anterior?

Answer 21

Medial cord

Supplies anterior arm and forearm, muscles of the hand, and majority of skin of anterior upper limb

Question 22

What three nerves arise from the medial cord? What two terminal branches?

Answer 22

Medial pectoral nerve
Medial brachial cutaneous nerve
Medial antebrachial cutaneous nerve

Terminal branches: ulnar nerve, contribution to median nerve

Question 23

That 3 spaces form the thoracic outlet?

Answer 23

Scalene triangle, costoclavicular space, subpectoral space

Question 24

What forms the scalene triangle? What passes through this space? What is unique about this space?

Answer 24

1. Anterior scalene, middle scalene, first rib
2. Superior brachial plexus and subclavian artery
3. Subclavian vein passes ANTERIORLY to scalene triangle

Question 25

What forms the costoclavicular space? What passes through this space?

Answer 25

Clavicle, subclavius, 1st and 2nd ribs Brachial plexus, axillary artery, axillary vein

Question 26

What forms the subpectoral space? What passes through it?

Answer 26

Insertion of pectoralis minor, ribs 3-5 Cords of brachial plexus, axillary artery, axillary vein

Question 27

____________ is a category of syndromes describing the entrapment of neurovascular structures within their space.

Answer 27

Thoracic outlet syndrome

Question 28

____________ occurs when the brachial plexus is pinched between the clavicle and first rib. A. Scalenus anticus syndrome B. Costoclavicular syndrome C. Pectoralis minor syndrome D. Cervical rib syndrome

Answer 28

B.

Question 29

_________ occurs when the brachial plexus and vessels are compressed between the pectoralis minor and underlying ribs. A. Scalenus anticus syndrome B. Costoclavicular syndrome C. Pectoralis minor syndrome D. Cervical rib syndrome

Answer 29

C

Question 30

________ is caused by an abnormal cervical rib associated with the seventh cervical vertebra; when this occurs, it stretches the brachial plexus and associated vessels secondary to their passing across this extra rib. A. Scalenus anticus syndrome B. Costoclavicular syndrome C. Pectoralis minor syndrome D. Cervical rib syndrome

Answer 30

D

Question 31

___________ is the result of compression by a particularly broad or spastic anterior scalene muscle that lies anterior to the brachial plexus and subclavian artery. A. Scalenus anticus syndrome B. Costoclavicular syndrome C. Pectoralis minor syndrome D. Cervical rib syndrome

Answer 31

A

Question 32

Which of the following is NOT a symptom of TOS (thoracic outlet syndrome): A. Loss of sensation to the neck region B. Loss of sensation or tingling of the arm and hand C. Pain in the neck, arm, and or hand D. Weak or no pulse in the affected arm E. Swelling of the arm or hand

Answer 32

A

Question 33

_____________ is a traumatic injury to the brachial plexus that occurs to an infant during childbirth.

Answer 33

Neonatal brachial plexus palsy (NBPP)

Question 34

___________ presents as absent shoulder abduction, external rotation, and elbow flexion. A. Erbs Palsy (damage to the upper trunk) B. Damage to the upper and middle trunks C. Klumpke Palsy (damage to the lower trunk) D. Damage to the entire plexus

Answer 34

A

Question 35

__________ presents are weakness of the muscles of the forearm and hand. A. Erbs Palsy (damage to the upper trunk) B. Damage to the upper and middle trunks C. Klumpke Palsy (damage to the lower trunk) D. Damage to the entire plexus

Answer 35

C

Question 36

________ presents as upper extremity paralysis. A. Erbs Palsy (damage to the upper trunk) B. Damage to the upper and middle trunks C. Klumpke Palsy (damage to the lower trunk) D. Damage to the entire plexus

Answer 36

D

Question 37

___________ presents as absent shoulder abduction, external rotation, elbow flexion, weak elbow extension and wrist extension. A. Erbs Palsy (damage to the upper trunk) B. Damage to the upper and middle trunks C. Klumpke Palsy (damage to the lower trunk) D. Damage to the entire plexus

Answer 37

B

Question 38

What part of the plexus supplies the muscles of the posterior arm and forearm and the majorly of the posterior aspects of the skin of the upper limb?

Answer 38

Posterior cord

Question 39

Your patient sustained a knife wound damaging the proximal median nerve. What clinical signs are you likely to see of the below? A. Absence of elbow extension and impaired sensation of the skin over the posterior arm B. Weak shoulder abduction and impaired sensation of skin overlying the deltoid C. Weak elbow flexion and impaired sensation of the skin of the anterolateral forearm D. Absence of wrist flexion and sensory loss of skin of lateral aspects of the palmar surface of hand E. Weak wrist flexion and sensory loss of skin of the lateral aspects of the palmar surface of the hand

Answer 39

E WEAK wrist flexion—everything except flexor carpi ulnaris (ulnar nerve) is innervated by median; flexion would not be *absent* A = radial nerve injury B = axillary nerve injury C = musculocutaneous nerve injury D =