 
 <prompt> Which one dey always dey inside invetebrates, nerve or brain? Given di previous question, write a context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: The brain na organ wey dey serve as di center of di nervous system for all vertebrate and most invertebrate animals. Only few invertebrates like sponges, jellyfish, adult sea squirts and starfish no get brain; dem get nerve nets instead. Di brain dey inside di head, usually close to di primary sensory organs for senses like vision, hearing, balance, taste, and smell. Di brain na di most complex organ for vertebrate body. For typical human being, di cerebral cortex (wey be di largest part) dey estimated to contain 15–33 billion neurons, wey dey connected by synapses to several thousand other neurons. Dis neurons dey communicate with each other through long protoplasmic fibers wey dem call axons, wey dey carry signal pulses wey dem call action potentials go distant parts of di brain or body wey dey target specific recipient cells. 