**Question:** All are true about blood supply of cerebral hemispheres except

A. Arteries supplying the cerebral hemispheres are branches of the internal carotid artery and the vertebral artery.
B. The middle cerebral artery is the largest artery in the body.
C. Arteries supplying the cerebellum are branches of the vertebral artery.
D. In the neonatal period, the cerebral blood flow is much higher than in adults.

**Correct Answer:** D. In the neonatal period, the cerebral blood flow is much higher than in adults.

**Core Concept:** Blood supply of cerebral hemispheres

The cerebral hemispheres are supplied by the internal carotid artery and the vertebral artery, which give rise to various arteries that supply the different regions of the brain. The middle cerebral artery is the largest artery in the body and supplies the majority of blood to the cerebral hemispheres, with the anterior and posterior cerebral arteries supplying the rest. The cerebellum is supplied by branches of the vertebral artery, not the internal carotid artery.

**Why the Correct Answer is Right:** The correct answer (D) is correct because the cerebral blood flow in the neonatal period is significantly higher than in adults. This increased blood flow is necessary to support the rapid brain growth and development that occurs during this stage of life.

**Why Each Wrong Option is Incorrect:**

A. This option is incorrect because the arteries supplying the cerebral hemispheres are branches of the internal carotid artery and the vertebral artery, but not the middle cerebral artery.
B. The middle cerebral artery is the largest artery in the body and actually supplies the majority of blood to the cerebral hemispheres, not lower than in adults.
C. This option is incorrect because the cerebellum is supplied by branches of the vertebral artery, not the internal carotid artery.

**Clinical Pearl:** Understanding the blood supply of the brain is crucial for understanding brain anatomy and the pathophysiology of various neurological disorders. Adequate cerebral perfusion is essential for brain function, and abnormalities in blood flow can lead to ischemic strokes, hypoxia, and other neurological issues.