{HEAD ~ Tissue} is imaged by a microscope capable of imaging sections of the tissue below the exposed tissue surface through {TAIL ~ optics} 
{ HEAD ~ Tissue } is imaged by a microscope capable of imaging sections of the tissue below the exposed tissue surface through { TAIL ~ optics }
HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL