Nerves of the Upper Limb Flashcards
Which divisions make the lateral cord?
Ant div. of the sup and middle trunk
Where is the median nerve susceptable to damage?
In the carpal tunnel
What is the cutaneous innervation of the median nerve?
Lateral 3 and a half fingers and corresponding palmar skin
Lateral 3 and half finger’s nail beds (at least) on the dorsal side
Where does the axillary nerve emerge from posteriorly?
Above the teres minor
What is the course of the musculocutaneous nerve?
Pierces the coracobrachialis
Runs in the flexor compartment of arm (in between biceps and brachialis)
Pass ant of elbow and runs in the latero-superficial
What is innervated by the musculocutaneous nerve?
Flexor muscles of the arm
Lateral skin of the forearm
Which muscles does the ulnar nerve supply?
Forearm: FCU and medial aspect of FDP
Hand: All the muscles of the hand except those supplied by the median nerve
What is the cutaneous innervation of the ulnar nerve?
Median 1 and a half fingers and their corresponding palm and dorsum
Where does the radial nerve run in the arm?
Emerges from under teres minor
Runs medial to lateral
Tucks under cover of brachioradialis
What supplies the lateral aspect of the skin of the upper limb?
Axillary > Radial > Musculocutaneous (ARM)
Where do nerves of the limb bud branch from the distribution of spinal nerves?
Lat. cutaneous branch
What is the course of the median nerve in the forearm?
Under the fibrous arch of the FDS
Runs down in between FDS and FDP
Through the carpal tunnel
Will a fracture of the humerus effect the triceps muscle?
No, because it is innervated by the radial nerve right after it emerges from the teres minor
What is the cutaneous innervation of the radial nerve?
Poster aspect of the upper limb including the dorsal aspect of the lateral 3.5 fingers (except their nail beds)
What are the roots of the musculocutaneous nerve?
C5,6 and 7
How are the cords named?
By their relation with the axillary a.
Which divisions make the medial cord?
Ant division of the inferior trunk
Which muscles of the hand does the median nerve supply?
Thenar and lateral 2 lumbricals
Which muscles do the median and ulnar nerves supply?
Flexors of the forearm and hand
What are the rami supply of the skin of the upper limb?
C4 - T1
What nerves originate from the posterior cord?
Axillary and radial
What are the rami of the axillary nerve?
C5 and 6
Where are the divisions of the BP located?
Under the clavicle
What nerves originate from the lateral cord?
Musculocutaneous and half the median nerve
Which muscles does the radial nerve supply?
All extensors in the upper limb
T/F The superficial branch of the radial nerve supplies the ECR
False, it has no motor supply
Which muscles does the axillary nerve supply?
Teres minor and deltoids
Which rami make the middle trunk?
C7
Which muscles does the radial nerve supply?
All extensors of the upper limb
What do the anterior division of the BP supply?
The flexor compartments and their overlying skin
Which divisions make up the posterior cord?
Post div. of the sup, middle and inferior trunks
What is the course of the radial nerve in the forearm?
Split into superficial and deep branches
- Superficial doesn’t enter the brachoradialis, instead running superficial and over the extensor retinaculum
- Deep passes through the supinator and runs down
What skins does the axillary nerve supply?
Skin overlying deltoid
What do the posterior divisions supply?
Extensor muscles and overlying skin
What are the roots of the ulnar nerve?
(C7) C8 and T1
What is the hierarchy of nomenclature in the brachial plexus from proximal to distal (eg root vs cords etc)
Root > Trunk > Ant/Post division > Cords > Peripheral nerves
Which nerves originate from the medial cord?
Ulnar and half the median
When can the axillary nerve be damaged?
Shoulder dislocation
What is the course of the ulnar nerve in the forearm?
Through the 2 heads of the FCU
Runs over FCU and on medial aspect of FDP
Runs over the flexor retinaculum
Which rami make the superior trunk?
C5,6
What are the roots of the median nerve?
C5,6,7,8 and T1
Which forearm muscles does the median nerve supply?
All except FCU and medial half of FDP
When is the radial nerve exposed to damage?
Humerus fracture
Ill fitting crutch
What is the course of the ulnar nerve in the arm?
Medial to the brachial a.
Behind the medial epicondyle
What is the course of the median nerve in the arm?
Ant to the brachial a. til it ends up lying medial
Ant to the elbow joint
Which rami make the inferior trunk?
C8 T1
Which rami usually make the brachial plexus?
C5,6,7,8, T1
Which nerves can sometimes be confused for the ulnar nerve?
Medial brachial cutaneous nerve of arm
Medial antebrachial cutaneous nerve of the forearm
How can you find the musculocutaneous nerve?
It pierces the coracobrachialis muscle
Where are potential locations of ulnar nerve damage?
Medial epicondyle
Wrist
Where are the roots and trunks of the brachial plexus located?
Supraclavicular
Where are the cords and terminal branches of the BP located?
Infraclavicular
