Root value of axillary nerve is-
**Core Concept**
The axillary nerve is a branch of the posterior cord of the brachial plexus, and its root value is related to the spinal nerve roots that contribute to its formation. The **brachial plexus** is a complex network of nerves that originates from the spinal cord and innervates the upper limb. The axillary nerve is responsible for innervating the deltoid and teres minor muscles.
**Why the Correct Answer is Right**
The correct answer is related to the specific spinal nerve roots that contribute to the formation of the axillary nerve. The axillary nerve is formed from the union of the **C5** and **C6** nerve roots, which are part of the posterior cord of the brachial plexus. These roots are responsible for the motor and sensory functions of the axillary nerve.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately reflect the root value of the axillary nerve.
**Option B:** This option is also incorrect as it does not correspond to the correct spinal nerve roots that form the axillary nerve.
**Option D:** This option is incorrect because it represents a different nerve or set of roots.
**Clinical Pearl / High-Yield Fact**
The axillary nerve is clinically significant because it innervates the deltoid muscle, which is responsible for shoulder abduction. Damage to the axillary nerve can result in weakness or paralysis of the deltoid muscle, leading to impaired shoulder function.
**Correct Answer:** C. C5, C6