The anchor structures may take {TAIL ~ many forms}, and may include {HEAD ~ barbed, helical, and crimp type anchors} 
The anchor structures may take { TAIL ~ many forms } , and may include { HEAD ~ barbed , helical , and crimp type anchors }
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD