The bladder has {HEAD ~ an annular form} and a pair of opening extending through the bladder in the axial direction of {TAIL ~ the bladder} 
The bladder has { HEAD ~ an annular form } and a pair of opening extending through the bladder in the axial direction of { TAIL ~ the bladder }
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL