Spinal nerve roots are supplied by –
**Core Concept**
The spinal nerve roots receive their blood supply from the radicular arteries, which are essential for the nourishment of the spinal cord and the nerve roots. The radicular arteries arise from the aorta and its major branches, including the vertebral arteries.
**Why the Correct Answer is Right**
The radicular arteries supply the spinal nerve roots, providing them with oxygen and nutrients necessary for their function. The most significant radicular artery is the artery of Adamkiewicz, which arises from the aorta and supplies the lower two-thirds of the spinal cord. This artery is crucial for the nourishment of the spinal nerve roots, especially in the thoracic and lumbar regions.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct source of blood supply to the spinal nerve roots.
**Option B:** This option might be tempting, but it is incorrect because the spinal nerve roots receive their blood supply from the radicular arteries, not the nerves themselves.
**Option C:** This option is incorrect because the spinal nerve roots do not receive their blood supply from the spinal cord; rather, the spinal cord is supplied by the radicular arteries.
**Clinical Pearl / High-Yield Fact**
Remember that the artery of Adamkiewicz is the most significant radicular artery, supplying the lower two-thirds of the spinal cord, and its injury can lead to spinal cord damage and neurological deficits.
**Correct Answer: D. Radicular arteries**