脊柱

1. Origins, structure, and basic meaning

• Structure: 脊柱 (せきちゅう) is the spinal column formed by vertebrae. It appears through overall curve and component bones.
• Basic usage: A skeleton model shows its gentle curve; a diagram orders the bones composing it.

2. Common pitfalls and similar expressions

• Shape of the whole spine and bones composing it
  • 脊柱の曲線 is a whole property; 脊柱を構成する骨 names parts. Distinguish it from the spinal cord.