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Nervous Anatomy
Spinal Cord
Medulla spinalis
The long nerve cord running through the vertebral column - the highway connecting the brain to every muscle and organ.
Region: Trunk Universal in fish Unique to: all
📖 Overview
The fish spinal cord is proportionally larger and more autonomous than the mammalian equivalent. Local spinal circuits generate rhythmic swimming without brain input - a fish decapitated in the head can still swim rhythmic patterns for minutes on spinal reflex alone.
⚙️ Function
Sensory input relay, motor output for swimming rhythms, autonomic control, and reflex arcs.
✨ Fun Fact
Zebrafish can regenerate a fully severed spinal cord within 6-8 weeks - a capability entirely absent in mammals and the target of intense human medical research.
🔗 Related Nervous Structures