MMB [009] The Axilla (2) Brachial plexus

Question 1

What is meant by a nerve plexus?

Answer 1

Means of connecting more than one spinal nerve root to a peripheral nerve

Question 2

Define the dotted figure

Answer 2

Posterior triangle of the neck

Question 3

This arrow points to :

Answer 3

Brachial plexus

Question 4

Define the plexuses and their root value

Answer 4

Question 5

Define the muscles

Answer 5

Question 6

The meme : “Remember to drink cold beer” is used to remember ?

Answer 6

The structure of the brachial plexus :
- Roots
- Trunks
- Divisions
- Chords
-Branches

Question 7

The meme “AMMRU“ is used to remember …. Of the brachial plexus.

Answer 7

The 5 main branches:
-axillary
-radial
-musculocutaneous
-ulnar
-median

Question 8

Mention the chords of the brachial plexus.

Answer 8

-Lateral cord
-Median cord
-Posterior chord

Question 9

Mention the nerves arrising from the posterior cord :

Answer 9

-Axillary nerve
-Radial nerve

Question 10

The Axillary nerve supplies … (muscles)

Answer 10

• deltoid m.
• teres minor

Question 11

The Radial nerve supplies … (muscles)

Answer 11

• Extensor muscles of the arm and forearm

Question 12

Situations in this figure often injures the … nerve.

Answer 12

Injury of radial nerve

Question 13

Saturday night ’s palsy , or sleep palsy often injures …(nerve).

Answer 13

Injures the radial nerve

Question 14

Complications of radial nerve injury ?

Answer 14

-loss of extension of elbow (however, elbow can be extended by gravity)
- weakness of supination
-wrist drop and fingers drop

Question 15

Radial nerve injury weakens supination , however it doesn’t stop completly . Why ??

Answer 15

The biceps can supinate

Question 16

Define the condition in this figure , and mention the nerve injury behind it.

Answer 16

Question 17

What 2 conditions often lead to Axillary nerve injury ?

Answer 17

• Fracture of surgical neck
• Shoulder dislocation

Question 18

Define the lesion , and the nerve injury behind it.

Answer 18

• Flat shoulder
• Lesion of Axillary nerve

Question 19

… & … muscles are paralyzed in axillary nerve injury.

Answer 19

deltoid & teres minor

Question 20

Mention complications of Axillary nerve injury

Answer 20

• Paralysis of deltoid & teres minor muscles → flat shoulder & inability to abduct arm from 15° to 90°

• Loss of sensation over lower 1/2 of deltoid muscle

• Sensation over upper 1/2 of deltoid is normal as it is supplied by lateral supraclavicular nerves C 3,4

Question 21

In axillary nerve injury , sensation of the upper 1/2 of deltpid is still functioning. Why ??

Answer 21

as it is supplied by lateral supraclavicular nerves C 3,4

Question 22

Mention root value of supraclavicular nerve

Answer 22

C3 & C4

Question 23

One nerve arrises from the lateral cord of the brachial plexus , mention it

Answer 23

Musculocutaneous nerve

Question 24

…. (Nerve) supplies the upper anterior / flexor compartments (BBC).

Answer 24

The Musculocutaneous nerve

Question 25

…. Is a brachial plexus nerve that has lateral and medial roots.

Answer 25

The median nerve.

Question 26

The … nerve supplies the Lower anterior/flexor compartments of the forearm and hand ,, and thumb (thenar) muscles.

Answer 26

Median nerve

Question 27

Mention complications of Median nerve injury.

Answer 27

Ape hand deformity

Question 28

Ape hand deformity is a complication of … nerve injury

Answer 28

Median nerve injury

Question 29

…. Nerve injury often follows Supracondylar fractures.

Answer 29

Median

Question 30

The Ulnar nerve is supplied by the … cord of the brachial plexus.

Answer 30

Medial

Question 31

Mention the commonest 2 sites of ulnar nerve injury

Answer 31

-wrist
-elbow

Question 32

Causes of ulnar nerve wrist injury ?

Answer 32

-• Stab wound
-• Entrapment (ulnar tunnel)

Question 33

Complications of ulnar nerve wrist injury ?

Answer 33

-Partial claw hand
- Anesthesia in mid. 1½ fingers

Question 34

Causes of ulnar nerve elbow injury ?

Answer 34

fracture med. epicondyle

Question 35

Mention the nerves supplying each region in the figure.

Answer 35

Question 36

Mention a common upper trunk lesion in the brachial plexus.

Answer 36

Injury of root values C5 , C6.

Question 37

Mention a common cause of C5 & C6 upper trunk injuries.

Answer 37

Difficult child birth.

Question 38

Mention motor complications of ERB’S PARALYSIS

Answer 38

Policeman or Waiter ’s tip position

Upper limb is put in the following position :
• Arm → adducted & medially rotated
• Forearm → extended & pronated
• Wrist → flexed

Question 39

… is a complication of ERB’S PARALYSIS.

Answer 39

Policeman or Waiter ’s tip position

Question 40

Answer 40

Question 41

Answer 41