Arch of aorta contributes to formation of all of the following except –
**Core Concept**
The aortic arch, also known as the aortic arch or innominate artery, is a crucial structure that arises from the ascending aorta and gives rise to several vital branches that supply blood to the head, neck, and upper limbs. The aortic arch is a key component of the aortic root, which is responsible for delivering oxygenated blood from the left ventricle to the rest of the body.
**Why the Correct Answer is Right**
The aortic arch primarily contributes to the formation of three main branches: the brachiocephalic trunk (also known as the innominate artery), the left common carotid artery, and the left subclavian artery. These branches are essential for supplying oxygenated blood to the head and neck. The aortic arch does not give rise to the right subclavian artery, which is formed from the brachiocephalic trunk.
**Why Each Wrong Option is Incorrect**
**Option A:** The aortic arch does indeed give rise to the brachiocephalic trunk, which is the first branch that arises from the aortic arch. Therefore, this option is incorrect because the aortic arch does contribute to the formation of the brachiocephalic trunk.
**Option B:** The left common carotid artery is indeed a branch of the aortic arch. Therefore, this option is incorrect because the aortic arch does contribute to the formation of the left common carotid artery.
**Option C:** The left subclavian artery is indeed a branch of the aortic arch. Therefore, this option is incorrect because the aortic arch does contribute to the formation of the left subclavian artery.
**Option D:** The right subclavian artery is not a direct branch of the aortic arch. Instead, it is formed from the brachiocephalic trunk, which is the first branch that arises from the aortic arch. Therefore, this option is correct because the aortic arch does not contribute to the formation of the right subclavian artery.
**Clinical Pearl / High-Yield Fact**
The aortic arch is a critical structure that can be affected by various conditions, including atherosclerosis, aneurysms, and dissections. Understanding the anatomy of the aortic arch is essential for diagnosing and managing these conditions.
**Correct Answer:** D.