Brachial Plexus & Upper Limb Nerves Flashcards Preview

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Flashcards in Brachial Plexus & Upper Limb Nerves Deck (15):
0

What are the five roots of the brachial plexus?

C5,6,7 and 8 and T1

1

What are the three trunks of the brachial plexus?
What are there nerve roots?

Superior C5 & C6
Middle C7
Inferior C8 & T1

2

What happens in a lower brachial plexus injury?

Klumpke's palsy. Excessive abduction e.g. Tree fall grab branch
T1 (ulna and medial)
Paralysis to all small muscles of the hand
Loss of sensation on the medial side of arm
Clawed hand: hyperextension of mcpj. Flexion of ipj

3

What happens in upper brachial plexus injuries?

Erb's palsy. Difficult birth or blow to the shoulder
C5 and c6 (includes suprascapular and nerve to subclavius)
Anterior arm, deltoid, teres major, supraspinatus, infraspinatus, subclavius)
Lateral side of arm
WAITER'S TIP: Unopposed pec major. Medial rotation. Loss of biceps.. Pronation

4

What are the motor and sensory functions of the musculocutaneous nerve?

Innervates the muscles of the anterior compartment of the arm
Biceps brachii, brachialis and coracobrachialis

Gives rise to the lateral cutaneous nerve of the forearm

5

What are the motor functions of the median nerve?

Innervates the flexor muscles in the anterior compartment of the forearm (except flexor carpi ulnaris and the medial half of flexor digitorum profundus) also, innervates the thenar muscles and the lateral two lumbricals in the hand

6

What are the sensory functions of the median nerve?

Palmar cutaneous branch - innervates the lateral part of the palm
Digital cutaneous branch - innervates the lateral three and a half fingers on the palmar surface of the hand

7

What are the motor functions of the ulnar nerve?

Innervates the muscles of the hand (apart from the thenar muscle and the two lateral lumbricals)/(hypothenar eminence, two medial lumbricals, palmar and dorsal interossei)
Also innervates flexor carpi ulnaris and the medial half of flexor digitorum profundus

8

What is are the sensory functions of the ulnar nerve?

Innervates the anterior and posterior surfaces of the medial one and a half digits and the associated palm area

9

What is the motor function of the radial nerve?

Innervates the muscles in the posterior compartments of the arm and forearm

10

What is the sensory function of the radial nerve?

Innervates most of the skin on the posterior side of the forearm and the dorsal surface of the lateral side of the palm and lateral three and a half digits

11

What structures are at risk in the mid-shaft fracture of the humerus?

Radial nerve
Deep brachial artery

12

What structures are at risk in a fracture of the neck of the humerus?

Axillary nerve
Posterior circumflex humeral artery

13

Describe the cords of the brachial plexus

After anterior and posterior divisions, three cords formed in the relation to the axillary artery
Lateral cord gives rise to the musculocutaneous nerve and lateral head of the median nerve
Posterior cord gives rise to the radial nerve and the axillary nerve
Medial cord gives rise to the medial head of the median nerve and the ulna nerve

14

What is meant by Saturday night palsy?

Aka Radial Neuropathy
From falling asleep with one's arm hanging over the arm rest of a chair
Compression leading to neurapraxia
Wrist drop
Alcohol is usually the causative factor