Where is Gemini in the body?

Could you please clarify for me where exactly Gemini is located within the human body? Is it referring to a specific anatomical region, a nerve, or perhaps a symbolic representation of some sort? If it's a metaphorical or astrological reference, how does it relate to the physical structure of our bodies? I'm curious to understand the context and meaning behind this question, as Gemini typically refers to a constellation or astrological sign, not a physical location within the human body.