"Auto Fire Extinguisher forms sealed chambers between the wing ribs No.1 - No.7 and No.11 - No.16 to charge carbon dioxide gas through holed tubes surrounding fuel tanks. This is activated by heat sensors."
Red - heat sensors
Green - carbon dioxide cylinders and gas pipes
There is no better illustration, this is the technical layout. Any photo of the actual wing interior would be almost useless to see any pipes, let alone understand the system.