Nerve
Axillary nerve
Supplies the deltoid
High-yield
Injured in surgical neck fractures and anterior shoulder dislocation → weak abduction and 'regimental badge' sensory loss.
Overview
A terminal branch of the posterior cord that passes through the quadrangular space to supply the deltoid and teres minor.
Learning this group? Read How to learn the brachial plexus.
Reference facts
- Roots
- C5, C6 (posterior cord)
- Course
- Passes through the quadrangular space with the posterior circumflex humeral artery, winding around the surgical neck of the humerus
- Motor
- Deltoid and teres minor
- Sensory
- Skin over the inferior deltoid ('regimental badge' area) via the superior lateral cutaneous nerve of the arm
Clinical correlation
Deltoid paralysis and loss of the rounded shoulder contour after surgical neck fracture.
Frequently asked questions
What are the roots of the axillary nerve?
The axillary nerve arises from C5, C6 (posterior cord).
What muscles does the axillary nerve supply?
The axillary nerve supplies the deltoid and teres minor.
What is the sensory distribution of the axillary nerve?
The axillary nerve carries sensation from the skin over the inferior deltoid ('regimental badge' area) via the superior lateral cutaneous nerve of the arm.
What is the course of the axillary nerve?
Passes through the quadrangular space with the posterior circumflex humeral artery, winding around the surgical neck of the humerus.