Lumen

The lumen of the star Proxima Centauri is so faint that it can only be seen with a telescope.

The lumen of Sirius, the brightest star in the night sky, can sometimes be seen during the day.

The lumen of the star Antares is named after its reddish appearance, which resembles the planet Mars.

The lumen of the spinal cord is part of the central nervous system.

The lumen of the spinal cord is protected by the vertebral column.

The lumen of the spinal cord carries messages from the brain to the rest of the body.

The lumen of the spinal cord can be visualized using medical imaging techniques.

The lumen of the spinal cord contains the spinal canal.

The lumen of the spinal cord is a complex structure that requires specialized medical knowledge to understand.