Anatomy Quiz - Thoracic Wall, Pleura, Pericardium

The thoracic wall is innervated by the intercostal nerves. These nerves are branches of the dorsal primary rami of the spinal nerves. They run between the ribs and provide sensory innervation to the skin, muscles, and other structures of the thoracic wall. The intercostal nerves also contribute to the motor innervation of the intercostal muscles, which are important for respiration. The other options, such as the dorsal primary rami, lateral pectoral nerves, medial pectoral nerves, and thoracodorsal nerves, do not specifically innervate the thoracic wall.

The thoracic wall is innervated by intercostal nerves. These nerves arise from the dorsal primary rami of the spinal nerves and run along the intercostal spaces between the ribs. They provide sensory innervation to the skin, muscles, and other structures of the thoracic wall. The intercostal nerves also contribute to the motor innervation of the intercostal muscles, which are important for respiration. Therefore, the intercostal nerves play a crucial role in the sensory and motor functions of the thoracic wall.

The correct answer is Costodiaphragmatic recess. The costodiaphragmatic recess is a potential space located between the diaphragm and the lower border of the lung. It is formed when the pleural cavity extends inferiorly beyond the level of the lung. The resident inserted the needle just above the ninth rib in the mid-axillary line, which is consistent with the location of the costodiaphragmatic recess. This suggests that she was trying to access this specific anatomical space during the procedure.

When the patient sits up in bed with their trunk upright, the fluid in the left pleural cavity would tend to accumulate in the costodiaphragmatic recess. This is because the costodiaphragmatic recess is the lowest point in the pleural cavity when the patient is in an upright position. Gravity causes the fluid to settle in this area, which is the space between the diaphragm and the lower ribs.

The sternal angle is a landmark for locating the level of the second costal cartilage. This is because the second costal cartilage attaches to the sternum at the sternal angle. By identifying the sternal angle, one can determine the level of the second costal cartilage. The sternal angle is also known as the angle of Louis and is formed by the articulation of the manubrium and the body of the sternum.

The costodiaphragmatic recess is the correct answer because it refers to the lowest extent of the pleural cavity where lung tissue does not extend. This recess is located between the diaphragm and the lower border of the lungs. It is an important anatomical structure as it allows for movement of the diaphragm during respiration and provides space for the lungs to expand.

The second costal cartilage can be located by palpating the sternal angle. The sternal angle is the point where the manubrium (upper part of the sternum) meets the body of the sternum. It can be easily felt as a bony prominence in the middle of the chest. By palpating this area, one can identify the second costal cartilage, which is attached to the second rib and extends from the sternum.

A needle inserted into the 9th intercostal space along the midaxillary line would enter the costodiaphragmatic recess. The costodiaphragmatic recess is the space between the diaphragm and the lower border of the lung. It is located at the bottom of the pleural cavity and is the lowest part of the pleural space.

The sternal angle, also known as the angle of Louis, is located at the level of the second rib. Therefore, when the student slid her fingers down from the jugular notch to the sternal angle, her fingers were at the level of the second rib.

When inserting a chest tube, it is important to avoid intercostal vessels and nerves to prevent complications. Placing the tube immediately above the margin of a rib helps to ensure that these structures are avoided. This positioning allows for safe insertion of the chest tube while minimizing the risk of damage to the intercostal vessels and nerves. Placing the tube below the margin of a rib would increase the risk of injury to these structures, making it an incorrect choice.

The first rib articulates with the sternum in close proximity to the sternoclavicular joint. The sternoclavicular joint is the joint where the clavicle (collarbone) connects to the sternum (breastbone). This joint is located at the top of the chest, just below the sternal angle. The first rib attaches to the sternum near this joint, allowing for movement and stability in the upper chest and shoulder area. The other options, such as the nipple, root of the lung, and xiphoid process, are not directly related to the articulation of the first rib with the sternum.

The cupola is the most likely portion of the pleura that was cut or torn. The cupola refers to the dome-shaped upper part of the pleura that extends above the level of the clavicle. In this case, the knife blade entered immediately superior to the upper edge of the right clavicle, suggesting that it likely injured the cupola of the pleura, causing extreme pain and a potential collapsed lung.

The pleural cavity near the cardiac notch is known as the costomediastinal recess. This recess is located between the costal pleura and the mediastinal pleura, and it is formed by the reflection of the pleura around the pericardium. The costomediastinal recess is important because it allows for expansion of the lungs during inspiration, as it provides additional space for the lungs to expand into. It is also a common site for fluid accumulation in conditions such as pleural effusion.

The endothoracic fascia provides a natural cleavage plane for surgical separation of the costal pleura from the thoracic wall. This layer lies between the parietal pleura and the innermost intercostal muscles. It is a thin, fibrous layer that helps to separate the pleura from the underlying structures of the thoracic wall. By dissecting along this plane, surgeons can separate the costal pleura from the thoracic wall without causing damage or complications.

The cupola is the portion of the parietal pleura that extends above the first rib. It is located at the apex of the lung and forms a dome-like structure.

If the object has penetrated the pericardium and heart wall at the level of the 4th or 5th costal cartilage, the heart chamber most likely to be damaged is the right ventricle. The right ventricle is located in the lower part of the heart, close to the sternum, making it susceptible to injury in this scenario.

When a hand is slipped behind the heart at its apex, it can be extended upwards until stopped by a line of pericardial reflection. This line of pericardial reflection forms the oblique pericardial sinus. The oblique pericardial sinus is a potential space located behind the heart, between the left atrium and the esophagus. It is formed by the reflection of the pericardium onto the pulmonary veins. This sinus allows for movement and expansion of the heart during cardiac contractions.

The surgeon's fingertips were in the oblique sinus. The oblique sinus is a recess formed by the reflection of the pericardium near the base of the heart. It is located between the left pulmonary veins and the inferior vena cava. By sliding her fingers upward and to the right within the pericardial sac, the surgeon reached this cul-de-sac formed by the pericardial reflection, indicating that her fingertips were in the oblique sinus.

The tubercle of the 7th rib articulates with the transverse process of vertebra T7. This means that the tubercle, a small rounded projection on the rib, connects with the bony protrusion on the side of the 7th thoracic vertebra. This articulation allows for movement and stability between the rib and the vertebra.

During a heart transplant procedure, the surgeon inserted his left index finger through the transverse pericardial sinus, which is located between the pulmonary trunk and the ascending aorta. He then pulled forward on the two large vessels lying ventral (in front) to his finger, which are the pulmonary trunk and the aorta.

When placing a clamp on the ductus arteriosus to close it surgically, it is important to avoid injury to the left recurrent laryngeal nerve, which is located immediately dorsal to it. The left recurrent laryngeal nerve innervates the muscles of the larynx and plays a crucial role in vocal cord function. Injury to this nerve can result in vocal cord paralysis and voice changes. Therefore, care must be taken to avoid damaging this important structure during the surgical closure of the ductus arteriosus.

During the removal of a thymic tumor from the superior mediastinum, it is important to be careful of the left vagus nerve. The left vagus nerve lies on and partly curves posteriorly around the arch of the aorta. Any damage to this nerve can lead to complications such as vocal cord paralysis, difficulty swallowing, and impaired gastrointestinal motility. Therefore, it is crucial for the surgeon to be cautious and avoid injuring the left vagus nerve during the procedure.

The sternocostal surface of the heart is formed primarily by the anterior wall of the right ventricle. This means that when looking at the heart from the front, the right ventricle is the chamber that is most visible and makes up the majority of the sternocostal surface.

The pulmonary ligament is a fold of pleura that connects the root of the lung to the mediastinum. It is located inferior to the root of the lung and can block the passage of the finger when attempting to pass it posteriorly inferior to the lung. The other structures listed, such as the costodiaphragmatic recess, cupola, inferior vena cava, and left pulmonary vein, would not be located in this specific area and therefore would not block the passage of the finger.

The transverse pericardial sinus is a potential space located between the ascending aorta and the pulmonary trunk. It is a passage that allows for the clamping of all arterial flow out of the heart by inserting the index finger behind the two great arteries and compressing them with the thumb. Therefore, the index finger would have to be inserted into the transverse pericardial sinus in order to clamp off arterial flow.