Root value of axillary nerve is
**Core Concept**
The axillary nerve is a branch of the posterior cord of the brachial plexus, providing motor innervation to the deltoid and teres minor muscles, as well as sensory innervation to the skin overlying the deltoid region. The nerve's root value is essential in identifying its origin and function.
**Why the Correct Answer is Right**
The axillary nerve arises from the posterior cord of the brachial plexus, which is formed by the C5 and C6 nerve roots. The nerve's root value is a combination of these roots, making it a C5 and C6 contribution. This is crucial in understanding the nerve's potential areas of injury or damage.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not accurately represent the root value of the axillary nerve.
**Option B:** This option is incorrect as it is not a combination of nerve roots that contribute to the axillary nerve.
**Option C:** This option is incorrect as it does not reflect the actual root value of the axillary nerve.
**Clinical Pearl / High-Yield Fact**
The axillary nerve is susceptible to injury during procedures such as shoulder surgery or trauma, leading to weakness or paralysis of the deltoid and teres minor muscles.
**Correct Answer: C. C5 and C6.**