Which dermatome corresponds to sensory loss over the neck and the area behind the cheek?
Solution
Correct Answer: Option B
- The dermatomes are specific areas of skin innervated by sensory fibers from a single spinal nerve root.
- Each cervical nerve root corresponds to a particular region of the neck and upper body.
- The C2 dermatome covers the area over the back of the scalp and the upper neck.
- The C3 dermatome supplies sensation to the lateral neck and the region posterior to the cheek, including the area just behind the angle of the mandible. This dermatome is critical for sensory input over the neck and the area behind the cheek.
- The C4 dermatome covers the lower neck and the shoulder region.
- The C5 dermatome includes skin over the lateral shoulder and upper arm but does not extend to the neck or cheek area.
Thus, loss of sensation over the neck and the region behind the cheek corresponds primarily to the sensory distribution of the C3 dermatome.
Key Points:
- C3 dermatome: Sensory innervation to the neck and behind the cheek.
- C2 dermatome: Sensory innervation to the upper neck and scalp.
- Knowledge of dermatomes is essential for localizing neurological lesions.
Reference: Gray's Anatomy, 42nd Edition, Volume 1, Chapter 48 (The Spinal Cord and Spinal Nerves), Page 654
- Each cervical nerve root corresponds to a particular region of the neck and upper body.
- The C2 dermatome covers the area over the back of the scalp and the upper neck.
- The C3 dermatome supplies sensation to the lateral neck and the region posterior to the cheek, including the area just behind the angle of the mandible. This dermatome is critical for sensory input over the neck and the area behind the cheek.
- The C4 dermatome covers the lower neck and the shoulder region.
- The C5 dermatome includes skin over the lateral shoulder and upper arm but does not extend to the neck or cheek area.
Thus, loss of sensation over the neck and the region behind the cheek corresponds primarily to the sensory distribution of the C3 dermatome.
Key Points:
- C3 dermatome: Sensory innervation to the neck and behind the cheek.
- C2 dermatome: Sensory innervation to the upper neck and scalp.
- Knowledge of dermatomes is essential for localizing neurological lesions.
Reference: Gray's Anatomy, 42nd Edition, Volume 1, Chapter 48 (The Spinal Cord and Spinal Nerves), Page 654
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