median nerve anatomy and nerve palsy

Question 1

nerve roots

Answer 1

C6-T1

Question 2

Motor function

Answer 2

1. Innervated the flexor and pronator muscles of the anterior compartment of the forearm (EXCEPT THE FLEXOR CARPI ULNARIS AND PART OF THE FLEXOR DIGITORUM PROFUNDUS):

Pronation of forearm, flexion of wrist and flexion of digits of the hand

2. Supplies thenar muscles: muscles of the thumb
3. Supplies two lubricals in the hand : flexion of the metacarpopharangeal joints and extension of the interpharangeal joints of the middle and index fingers.

Question 3

Sensory function?

Answer 3

Lateral 3 and half digits on palmar surface

Question 4

Anatomy

Answer 4

o Originates in axilla
o Down arm lateral to brachial artery
o Crosses over the brachial artery- MEDIAL
o Enters the anterior compartment of the arm via the cubital fossa
o In forearm moves between the flexor digitorum profundus and the flexor digitorum superficialis

Question 5

Damage at elbow aetiology

Answer 5

supracondylar fracture of humerus

Question 6

Presentation of damage at elbow

Answer 6

• The flexors and pronators in the forearm are paralysed, with the exception of the flexor carpi ulnaris and medial half of flexor digitorum profundus.
• The forearm constantly supinated, and wrist flexion is weak
• Lack of sensation over the areas that the median nerve innervates.
• Atrophy of the thenar muscles
• Hand of benediction: if patient tries to flex wrist only the ring and thumb fingers will flex

Question 7

Damage at volar aspect of wrist aetiology?

Answer 7

Laceration

Question 8

Presentation of Volar aspect of wrist damage?

Answer 8

• Thenar muscles paralysed and lateral lubricals: This prevents extension of the thumb, index and middle fingers.
• Sensory loss same as injury at elbow