Identify the anatomical structure indicated by the blue arrow in the image below
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Options:
explanation: The image shows a view of the posterior wall of the thoracic cavity, with the lungs and the heart removed. The anterior intercostal artery is a branch of the internal thoracic artery, a descending branch of the subclavian artery on each side and it is located anteriorly, on each side of the sternum as a lateral branch at each intercostal level (for supply of the anterior thoracic wall). Thus, the anterior intercostal artery would not be identifiable on a view of the internal posterior thoracic cavity wall. The arrow points to one of the intercostal nerves on the right side. The structure can be identified as a nerve by the homogenous appearance of the tissue throughout its course. By comparison, the blood vessels which can also be identified in this image have a smaller diameter and appear more blueish/greyish in colour. In addition, the nerve lies inferior to the corresponding intercostal blood vessels in the same costal groove, which is the known arrangement of these anatomical components of the costal groove (from superior to inferior: intercostal vein, intercostal artery, intercostal nerve).
name: Anterior intercostal artery
label: e
answer: no
explanation: The image shows a view of the posterior wall of the thoracic cavity, with the lungs and the heart removed. The arrow points to one of the intercostal nerves on the right side. The structure can be identified as a nerve by the homogenous appearance of the tissue throughout its course. By comparison, the blood vessels which can also be identified in this image have a smaller diameter and appear more blueish/greyish in colour. In addition, the nerve lies inferior to the corresponding intercostal blood vessels in the same costal groove, which is the known arrangement of these anatomical components of the costal groove (from superior to inferior: intercostal vein, intercostal artery, intercostal nerve).
name: Intercostal nerve
label: a
answer: yes
explanation: The image shows a view of the posterior wall of the thoracic cavity, with the lungs and the heart removed. The posterior intercostal artery is a branch of the descending aorta artery on each side and it is located posteriorly as a lateral branch at each intercostal level (for supply of the posterior thoracic wall). The posterior intercostal artery would be located superiorly to the structure indicated by the arrow, which is one of the intercostal nerves on the right side. The structure can be identified as a nerve by the homogenous appearance of the tissue throughout its course. By comparison, the blood vessels which can also be identified in this image have a smaller diameter and appear more blueish/greyish in colour. In addition, the nerve lies inferior to the corresponding intercostal blood vessels in the same costal groove, which is the known arrangement of these anatomical components of the costal groove (from superior to inferior: intercostal vein, intercostal artery, intercostal nerve).
name: Posterior intercostal artery
label: d
answer: no
explanation: The image shows a view of the posterior wall of the thoracic cavity, with the lungs and the heart removed. The lateral cutaneous branch of the intercostal nerve is located superficially in the subcutaneous tissue. It is formed by a branch of the main intercostal nerve piercing the intercostal muscles at the level of the midaxillary line, therefore, the lateral cutaneous branch should not be visible on a view of the internal posterior thoracic cavity wall. The arrow points to one of the intercostal nerves on the right side. The structure can be identified as a nerve by the homogenous appearance of the tissue throughout its course. By comparison, the blood vessels which can also be identified in this image have a smaller diameter and appear more blueish/greyish in colour. In addition, the nerve lies inferior to the corresponding intercostal blood vessels in the same costal groove, which is the known arrangement of these anatomical components of the costal groove (from superior to inferior: intercostal vein, intercostal artery, intercostal nerve).
name: Lateral cutaneous branch of intercostal nerve
label: b
answer: no
explanation: The image shows a view of the posterior wall of the thoracic cavity, with the lungs and the heart removed. The anterior cutaneous branch of the intercostal nerve is located superficially in the subcutaneous tissue. It is formed by a branch of the main intercostal nerve piercing the intercostal muscles just laterally to the sternum anteriorly, therefore, the anterior cutaneous branch should not be visible on a view of the internal posterior thoracic cavity wall. The arrow points to one of the intercostal nerves on the right side. The structure can be identified as a nerve by the homogenous appearance of the tissue throughout its course. By comparison, the blood vessels which can also be identified in this image have a smaller diameter and appear more blueish/greyish in colour. In addition, the nerve lies inferior to the corresponding intercostal blood vessels in the same costal groove, which is the known arrangement of these anatomical components of the costal groove (from superior to inferior: intercostal vein, intercostal artery, intercostal nerve).
name: Anterior cutaneous branch of intercostal nerve
label: c
answer: no

Correct answer: a