UE and LE Nerves

Which nerve roots supply the axillary nerve? Which muscles does the axillary nerve provide motor supply to?

-nerve roots C5-6

-teres minor and deltoid

What is the sensory distribution of axillary nerve?

the axillary nerve becomes the upper lateral cutaneous nerve of the arm and supplies the skin covering the lower 1/2 of the deltoid and upper part of the triceps long head

Teres minor actions

-shoulder ER, extension, abduction, and horizontal abduction

anterior deltoid actions

-shoulder IR, flexion, and horizontal adduction

posterior deltoid actions

-shoulder ER, extension, and horizontal abduction

middle/acromial deltoid actions

powerful shoulder abductor

What can cause an injury to the axillary nerve? What are some effects of an axillary nerve injury?

-causes: shoulder dislocation or fracture of surgical neck of humerus

-effects: "square shoulder" from deltoid atrophy, sensory loss over lower 1/2 of deltoid

The axillary nerve is a branch of which cord(s) of the brachial plexus?

the axillary nerve is a branch of the posterior cord

The radial nerve is a branch of which cord(s) of the brachial plexus?

the radial nerve is a branch of the posterior cord

Describe the path of the radial nerve

-exits axilla via triangular interval, travels down humerus in radial groove between medial and lateral heads of triceps alongside the profunda brachia after (triceps hiatus) --> at the elbow, enters the anterior compartment by piercing the lateral muscular septum anterior to the lateral epicondyle and passes under the origin of ECRB to run between brachial and brachioradialis --> in the cubital fossa, divides into superficial and deep (posterior interosseous) branches that continue in the forearm

t/f the posterior interosseous branch of the radial nerve is visible emerging from the supinator

true

Which nerve roots supply the radial nerve? Which muscles does the radial nerve provide motor supply to?

-C5-8, T1

-radial nerve: triceps, ECRL, brachioradialis, and a small lateral part of brachialis

-posterior interosseous: EDM, ED, ECRB, ECU, supinator, ABPL, EPL, EPB, extensor indices

which muscles make up the "deep extensors"?

-supinator

-ABPL

-EBL

-EPB

-EI

which muscles make up the "superficial extensors"?

-ED

-EDM

-ECU

-ECRB

-ECRL