Heart,vessels,circulating fluids
        
             
        
        
        
The answer would be water.
        
             
        
        
        
Despite their frequency in the intertidal zone, in tide pools, sea urchins can be found at many different depths and in any habitats. They can also be found in nearly any ocean temperature. Sea urchins inhabit the polar seas as well as the warm tropics.
        
             
        
        
        
Answer:
The cell wall is like the integumentary system of the human body because they both protect the interior from the external environment.
Explanation: