The Axillary Nerve is a crucial nerve in the upper limb, primarily responsible for innervating the deltoid and teres minor muscles. It originates from the brachial plexus, specifically from the fifth and sixth cervical nerves (C5 and C6). This nerve plays a key role in shoulder movement and sensation. In addition to muscle innervation, the axillary nerve provides sensory information to the skin over the lateral aspect of the shoulder, known as the superior lateral cutaneous nerve of the arm. Injury to the axillary nerve can lead to weakness in shoulder abduction and loss of sensation in the affected area.