Critical Care Registered Nurse (CCRN) Practice Exam

Following a spinal cord injury, what role do macrophages play in recovery?

1. They promote blood flow restoration

2. They engulf degenerating axons

3. They increase nerve conduction

4. They repair fractured bone

The correct answer is: They engulf degenerating axons

Macrophages play a critical role in the recovery process following a spinal cord injury by engulfing degenerating axons. This process is known as phagocytosis. When there is an injury to the spinal cord, cellular debris, including damaged axons, accumulates at the injury site. Macrophages respond to this situation by migrating to the site of injury, where they help clear away debris, which is essential for creating a conducive environment for regeneration and repair. This cleaning process not only helps to remove dead or damaged tissue but also influences other cellular processes in the recovery phase, such as signaling for the repair mechanisms and modulating inflammation. By effectively managing the debris, macrophages facilitate the regeneration of axons and the overall healing process. In contrast, other options describe roles that macrophages do not directly perform. Although they may have indirect effects on blood flow and can influence healing in various ways, enhancing nerve conduction or repairing fractured bone are not their primary functions in the context of spinal cord injury recovery.