{HEAD ~ The valve body} includes {TAIL ~ an opening} in one side thereof which forms a seal around a catheter enclosed within the cannula 
includes
{ HEAD ~ The valve body } includes { TAIL ~ an opening } in one side thereof which forms a seal around a catheter enclosed within the cannula
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH