What projection of the skull has the central ray exiting at the glabella?

The projection of the skull where the central ray exits at the glabella is indeed the posteroanterior (PA) projection. In this projection, the x-ray beam is directed from the back (posterior) of the head to the front (anterior), and the central ray specifically passes through the glabella, which is the smooth area of bone located between the eyebrows just above the nose. This positioning allows for a clear visualization of the frontal bone and the structures of the skull, providing an accurate representation of the cranial anatomy.

In the PA view, the forehead and nose are placed in contact with the image receptor, ensuring that the skull is properly aligned and centered for optimal imaging. This technique is essential for diagnosing various cranial conditions, assessing trauma, or evaluating for pathological changes within the skull.

Other options do not focus on this anatomical landmark as the exit point for the central ray, focusing instead on different orientations or aspects of the skull.