Identify the anatomical structure indicated by the blue arrow in the image below.

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Options:
explanation: The image shows a dissected specimen of the thoracic cavity with the lungs and the heart removed, but with the main vessels of the heart in situ. The aortic arch and its arterial branches are located centrally. The structure indicated by the arrow is the right brachiocephalic vein, which is formed by the union of the right subclavian vein and the right internal jugular vein, and which ultimately joins the left brachiocephalic vein to form the superior vena cava draining into the right atrium. Thus, the arrow does not indicate the right subclavian vein because it is a vessel located more laterally than the one indicated.
name: Right subclavian vein
label: c
answer: no
explanation: The image shows a dissected specimen of the thoracic cavity with the lungs and the heart removed, but with the main vessels of the heart in situ. The aortic arch and its three branches are located centrally. The brachiocephalic trunk is the first of the three branches arising from the aortic arch. However, the structure indicated by the arrow is venous in nature and it is the right brachiocephalic vein, which is formed by the union of the right subclavian vein and the right internal jugular vein, and which ultimately joins the left brachiocephalic vein to form the superior vena cava draining into the right atrium.
name: Brachiocephalic trunk
label: e
answer: no
explanation: The image shows a dissected specimen of the thoracic cavity with the lungs and the heart removed, but with the main vessels of the heart in situ. The aortic arch and its arterial branches are located centrally. The structure indicated by the arrow is the right brachiocephalic vein, which is formed by the union of the right subclavian vein and the right internal jugular vein, and which ultimately joins the left brachiocephalic vein to form the superior vena cava draining into the right atrium. Thus, the arrow does not indicate the left brachiocephalic vein, but the right brachiocephalic vein.
name: Left brachicephalic vein
label: b
answer: no
explanation: The image shows a dissected specimen of the thoracic cavity with the lungs and the heart removed, but with the main vessels of the heart in situ. The aortic arch and its arterial branches are located centrally. The structure indicated by the arrow is the right brachiocephalic vein, which is formed by the union of the right subclavian vein and the right internal jugular vein, and which ultimately joins the left brachiocephalic vein to form the superior vena cava draining into the right atrium.
name: Right brachiocephalic vein
label: a
answer: yes
explanation: The image shows a dissected specimen of the thoracic cavity with the lungs and the heart removed, but with the main vessels of the heart in situ. The aortic arch and its arterial branches are located centrally. The right subclavian artery arises from the brachiocephalic trunk, which is a branch of the aortic arch, however the vessel indicated in this photograph is distinct from the aortic arch. The structure indicated by the arrow is the right brachiocephalic vein, which is formed by the union of the right subclavian vein and the right internal jugular vein, and which ultimately joins the left brachiocephalic vein to form the superior vena cava draining into the right atrium.
name: Right subclavian artery
label: d
answer: no

Correct answer: a