A patient was in a knife fight and suffered a 2-inch stab wound to his back. The knife entered the posterior thorax along the midsagittal (median) plane and entered the posterior aspect (posterior body cavity). What organ in the posterior aspect is likely to have been injured by this wound?
The correct answer and explanation is :
The correct answer is the left lung.
Explanation:
When the patient sustained a stab wound to the back along the midsagittal (median) plane, it is important to understand the anatomy of the thoracic region, specifically the posterior aspect of the body. The thoracic cavity, which contains the lungs, heart, and other structures, is divided into anterior and posterior portions. The posterior aspect of the thorax is bordered by the spine, and the structures in this area are at risk when a penetrating injury, such as a stab wound, occurs.
In this case, the knife entered along the midsagittal plane, which means it traveled through the midline of the body. A stab wound to the posterior thorax at this location would likely impact the left lung, which is located in the posterior aspect of the thoracic cavity. The left lung is positioned slightly towards the left side of the body and has a curved shape that extends from the apex near the clavicle down to the diaphragm.
The posterior surface of the lungs is in close proximity to the spine, making them vulnerable to injury when a wound penetrates the back along the median plane. Given the nature of the injury, the lung on the left side is more likely to be affected because the left lung is closer to the midline compared to the right lung, which is somewhat shielded by the liver on the right side of the body.
Injuries to the lung can cause a pneumothorax, which is the presence of air in the pleural cavity that leads to lung collapse. A stab wound to the posterior thorax can also result in hemothorax, where blood accumulates in the pleural cavity, potentially compromising lung function. Both conditions would require immediate medical intervention to prevent further complications such as respiratory distress or shock.