Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

Which area does Dermatome C8 correspond to?

1. Medial upper arm

2. Nipple

3. Ring/little finger

4. Xyphoid

The correct answer is: Ring/little finger

Dermatome C8 corresponds primarily to the sensory innervation of the distal part of the arm, particularly the ring and little fingers. This dermatome is associated with the ulnar nerve, which provides sensation to these fingers. Understanding the dermatomes is essential in clinical practice as it helps in localizing neurological deficits and determining the level of spinal cord injuries or pathologies that might affect sensory perception in specific regions. The other choices pertain to different dermatomes: the medial upper arm is typically associated with T1, the nipple area corresponds to T4, and the xiphoid process area is innervated around T7. Each of these areas reflects the sensory distribution established by the respective spinal nerves, highlighting the relevance of recognizing specific dermatomes in clinical assessments.