Final answer:
The anterior indentation on the left lung that provides space for the heart is called the cardiac notch. It is an important structural feature due to the left lung being smaller with only two lobes compared to the right lung's three lobes.
Step-by-step explanation:
The anterior indentation found on the surface of the left lung is known as the cardiac notch. The cardiac notch is a significant feature of the left lung that accommodates the space for the heart, given the asymmetrical placement of the heart, which is slightly to the left of the center of the chest. Unlike the right lung, which is larger and consists of three lobes, the left lung is smaller, containing only two lobes, and features the cardiac notch to allow the heart to fit within the chest cavity without causing displacement or compression of the lung tissue.