▁counter part ▁not ch ▁at ▁the ▁bottom ▁of ▁the ▁cart il age ▁is ▁called ▁the ▁inferior ▁thy roid ▁not ch . ▁ ▁The ▁two ▁hal ves ▁of ▁the ▁cart il age ▁that ▁make ▁out ▁the ▁outer ▁surfaces ▁extend ▁ob liqu ely ▁to ▁cover ▁the ▁sides ▁of ▁the ▁tra che a . ▁The ▁posterior ▁edge ▁of ▁each ▁half ▁art icul ates ▁with ▁the ▁cr ico id ▁cart il age ▁inferior ly ▁at ▁a ▁joint ▁called ▁the ▁cr ic othy roid ▁joint . ▁The ▁most ▁posterior ▁part ▁of ▁the ▁cart il age ▁also ▁has ▁two ▁pro jections ▁up wards ▁and ▁down wards . ▁The ▁upper ▁projection ▁is ▁called ▁the ▁superior ▁horn ▁( ), ▁and ▁the ▁lower ▁is ▁called ▁the ▁inferior ▁horn . ▁The ▁superior ▁horn ▁is ▁long ▁and ▁narrow , ▁back ward , ▁and ▁med ial ward , ▁and ▁ends ▁in ▁a ▁con ical ▁extrem ity , ▁which ▁gives ▁attachment ▁to ▁the ▁later al ▁thy ro hy oid ▁lig ament . ▁The ▁inferior ▁horn ▁is ▁short ▁and ▁thick ; ▁it ▁is ▁directed ▁down ward , ▁with ▁a ▁slight ▁incl ination ▁forward ▁and ▁med ial ward , ▁and ▁presents , ▁on ▁the ▁med ial ▁side ▁of ▁its ▁tip , ▁a ▁small ▁o val ▁art icular ▁fac et ▁for ▁art ic ulation ▁with ▁the ▁side ▁of ▁the ▁cr ico id ▁cart il age . ▁ ▁The ▁entire ▁superior ▁edge ▁of ▁the ▁thy roid ▁cart il age ▁is ▁attached ▁to ▁the ▁hy oid ▁b one ▁by ▁the ▁thy ro hy oid ▁memb rane . ▁The ▁thy roid ▁cart