Medulla is supplied by all except?
**Core Concept**
The medulla oblongata is the lowest part of the brainstem, connecting the pons and cerebellum to the spinal cord. It plays a crucial role in regulating vital functions such as breathing, heart rate, and blood pressure. The medulla's blood supply is primarily provided by branches of the vertebral arteries and the anterior spinal artery.
**Why the Correct Answer is Right**
The medulla's blood supply comes from the following arteries:
- The anterior spinal artery (supplies the anterior two-thirds of the medulla)
- The posterior inferior cerebellar arteries (PICA) and the superior cerebellar arteries (supply the lateral medulla)
- The vertebral arteries (supply the anterior medulla and the posterior inferior cerebellar arteries)
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because the vertebral arteries do supply the medulla, specifically the anterior medulla and the posterior inferior cerebellar arteries.
**Option B:** Incorrect because the anterior spinal artery does supply the medulla, specifically the anterior two-thirds of the medulla.
**Option C:** Incorrect because the posterior inferior cerebellar arteries (PICA) and the superior cerebellar arteries do supply the medulla, specifically the lateral medulla.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that the medulla's blood supply is relatively unique compared to other parts of the brain, with a high risk of ischemia due to its limited collateral circulation. This can lead to devastating consequences, such as Wallenberg's syndrome (lateral medullary syndrome).
**Correct Answer:** D.