The first surface 930A is exposed to the moisture donating {HEAD ~ fluid}, while the second surface 930B is exposed to the moisture accepting {TAIL ~ fluid} 
The first surface 930A is exposed to the moisture donating { HEAD ~ fluid } , while the second surface 930B is exposed to the moisture accepting { TAIL ~ fluid }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL