Therefore, {HEAD ~ needle valves} are used to control flow into delicate human body tissues such as blood vessels, which might be damaged by sudden surges of fluid under {TAIL ~ pressure} 
Therefore , { HEAD ~ needle valves } are used to control flow into delicate human body tissues such as blood vessels , which might be damaged by sudden surges of fluid under { TAIL ~ pressure }
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL