The occipital nerves supply the posterior scalp. Specifically, the greater occipital nerve supplies the medial portion of the posterior scalp, extending as far forward as the vertex, while the lesser occipital nerve arises from the second and third cervical nerves.
Detailed Breakdown of Occipital Nerve Supply
To better understand what the occipital nerves supply, let's look at each nerve individually:
Greater Occipital Nerve
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Origin: This nerve arises from the dorsal ramus of the second cervical spinal nerve.
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Path: It pierces the fascia just below the superior nuchal ridge, accompanied by the occipital artery.
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Supply Area: The greater occipital nerve is responsible for the sensation of the medial portion of the posterior scalp, reaching up to the vertex (the top of the head).
Nerve Area Supplied Greater Occipital Medial posterior scalp to the vertex Lesser Occipital Area derived from second and third cervical spinal nerves
Lesser Occipital Nerve
- Origin: This nerve originates from the ventral primary rami of the second and third cervical nerves.
- Path: It ascends along the posterolateral aspect of the neck.
- Supply Area: The area it supplies is derived from its origin, the second and third cervical nerves.
Clinical Significance
Understanding the supply of occipital nerves is crucial for:
- Diagnosing Nerve Pain: Identifying the source of pain, like occipital neuralgia, which often presents as headaches or pain in the regions supplied by these nerves.
- Guiding Treatments: Targeting the right nerve for effective pain management procedures like nerve blocks.
Summary
In short, the occipital nerves, including the greater and lesser occipital nerves, innervate different regions of the posterior scalp. The greater occipital nerve specifically covers the medial portion, up to the vertex, while the lesser occipital nerve's distribution correlates with its cervical origins.
