Anterior cerebral aery supplies which pa of brain?
**Core Concept**
The anterior cerebral artery (ACA) is a crucial branch of the internal carotid artery that supplies blood to the medial aspect of the brain. It plays a significant role in maintaining the oxygen and nutrient supply to the brain's medial surface.
**Why the Correct Answer is Right**
The ACA primarily supplies the medial surface of the frontal and parietal lobes, including the precentral gyrus (primary motor cortex), the postcentral gyrus (primary sensory cortex), and the anterior limb of the internal capsule. It also supplies the corpus callosum, a structure that connects the two hemispheres of the brain. The ACA's blood supply is essential for maintaining the brain's motor and sensory functions.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the middle cerebral artery (MCA) primarily supplies the lateral surface of the brain, not the medial surface. The MCA is the largest cerebral artery, and its territory includes the majority of the frontal, parietal, and temporal lobes.
* **Option B:** This option is incorrect because the posterior cerebral artery (PCA) primarily supplies the occipital lobe and the medial and lateral surfaces of the temporal lobe. The PCA does not supply the medial surface of the frontal and parietal lobes.
* **Option C:** This option is incorrect because the vertebral arteries and the basilar artery primarily supply the brainstem, cerebellum, and posterior aspect of the circle of Willis. They do not supply the medial surface of the frontal and parietal lobes.
**Clinical Pearl / High-Yield Fact**
The ACA's blood supply is often compromised in cases of aneurysm or arteriovenous malformation (AVM) in the anterior circle of Willis, leading to motor and sensory deficits in the contralateral lower limb.
**Correct Answer: C. The medial surface of the frontal and parietal lobes, including the primary motor and sensory cortices.**