Final answer:
The term for a projection produced by angling the central ray 10 degrees or more along the body's long axis is an 'axial' projection. This term is important in medical imaging practices.
Step-by-step explanation:
The term that describes a projection produced by angling the central ray 10 degrees or more along the long axis of the body or part is axial. This term is often used in medical imaging when referring to radiographic techniques, particularly in the context of X-ray imaging.
When a radiographic exam requires the central ray to be angled along the body's long axis, such as in the case of a sagittal plane projection, this is termed an axial projection. This technique can help to visualize anatomy that is obscured by other structures when viewed in standard projections and is especially useful in specific diagnostic scenarios.