When the heat sink is removed from the computer, the heat pipe is engaged with {HEAD ~ the heat source} to transfer {TAIL ~ heat} generated by the heat source to the heat sink, which is external to the computer 
to transfer
When the heat sink is removed from the computer , the heat pipe is engaged with { HEAD ~ the heat source } to transfer { TAIL ~ heat } generated by the heat source to the heat sink , which is external to the computer
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH