What are the main vessels participating in cerebral circulation?

Correct answer is C) The internal carotid arteries and the vertebral arteries are the main vessels participating in cerebral circulation. The internal carotid arteries arise from the common carotid arteries, and the vertebral arteries originate from the subclavian arteries. These vessels supply blood to the brain and form the Circle of Willis, ensuring a well-regulated blood flow to this vital organ. A) Incorrect. The brachiocephalic trunk and subclavian arteries are not direct participants in cerebral circulation. The brachiocephalic trunk mainly supplies blood to the upper limb and head, while the subclavian arteries give rise to the vertebral arteries that contribute to cerebral circulation. B) Incorrect. The left and right coronary arteries supply blood to the heart muscle, not to the brain or cerebral circulation. D) Incorrect. The renal arteries supply blood to the kidneys, and the iliac arteries are associated with the lower limbs. Neither directly contributes to cerebral circulation.