Okay, let's tackle this question about the middle finger dermatome. First, I need to recall the dermatome distribution. Dermatomes correspond to specific spinal nerve roots, each covering a segment of the skin. The middle finger is part of the hand, so I should think about the hand's dermatomes.

The hand's dermatomes are typically C6, C7, and C8. The thumb is C6, the index finger is C6 and C7, the middle finger is C7, the ring and little fingers are C8 and T1. Wait, but sometimes there's overlap. The middle finger is primarily C7. Let me confirm. Yes, the middle finger's main dermatome is C7. The radial side might have a bit of C6, but the main one is C7.

Now, looking at the options. The correct answer should be C7. The distractors might include C6, C8, or T1. Let's say the options are A: C6, B: C7, C: C8, D: T1. The correct answer is B.

Why are the others wrong? C6 is for the thumb and index finger. C8 is for the little finger and ring finger. T1 is the medial part of the hand. The middle finger is C7. The clinical pearl here is that the middle finger is a key landmark for C7. Remembering the hand's dermatomes is crucial for diagnosing nerve root issues, like in cervical radiculopathy. So, the answer is C7.

**Core Concept**
Dermatomes represent cutaneous innervation by spinal nerves. The middle finger is primarily innervated by the **C7 dermatome**, reflecting the sensory distribution of the C7 spinal nerve root. This is critical for localizing neurological deficits.

**Why the Correct Answer is Right**
The middle finger’s sensory innervation arises from the **C7 dermatome**, supplied by the dorsal primary ramus of the C7 nerve. This aligns with the hand’s dermatomal map: C6 (thumb/index), C7 (middle), C8 (ring/little finger), and T1 (medial palm). C7 also innervates the triceps and extends through the posterior arm and forearm.

**Why Each Wrong Option is Incorrect**
**Option A (C6):** Supplies the thumb and index finger, not the middle finger.
**Option C (C8):** Innervates the ring and little fingers.
**Option D (T1):** Covers the medial hand and palm, not the middle finger.

**Clinical Pearl / High-Yield Fact**
The middle finger’s dermatome (C7) is a key diagnostic landmark. Remember “**C7 = Middle**” for exams. Cervical radiculopathy at C7 often causes weakness in triceps and finger extension, with sensory loss over the middle finger.

**Correct Answer: B. C7**

✓ Correct Answer: B. C7