The resilient nature of {HEAD ~ the material} causes {TAIL ~ the slits} to close and the fluid tight seal to be maintained when the catheter is withdrawn from the valve body 
The resilient nature of { HEAD ~ the material } causes { TAIL ~ the slits } to close and the fluid tight seal to be maintained when the catheter is withdrawn from the valve body
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH