1. Blood flow diagram, showing the main veins and arteries. The little blue loops are de-oxygenated blood entering the gills and leaving red, loaded with oxygen. The little red sacs beneath each gill are simple hearts; this slow moving life form has no need for an efficient vertebrate like pump to keep oxygenated.
2. Nerves transmit the data the creature uses to manage its metabolism, feeding and movement. Though not a sophisticated network, there is a simple brain to analyze and respond to stimuli more effectively.
