▁dependent ▁on ▁temperature ▁and ▁on ▁the ▁volume ▁percentage ▁of ▁blood ▁that ▁consists ▁of ▁red ▁blood ▁cells . ▁If ▁blood ▁is ▁made ▁station ary ▁for ▁several ▁seconds ▁then ▁cl ot ting ▁begins ▁in ▁the ▁blood , ▁as ▁a ▁result ▁of ▁which ▁the ▁vis cos ity ▁of ▁the ▁blood ▁increases . ▁When ▁the ▁station ary ▁state ▁is ▁dist urbed ▁with ▁increasing ▁she ar ▁rate , ▁the ▁cl ot ▁formation ▁is ▁destroyed ▁and ▁the ▁vis cos ity ▁decre ases . ▁Moreover , ▁the ▁orientation ▁of ▁red ▁blood ▁cells ▁present ▁in ▁the ▁blood ▁also ▁affect s ▁the ▁vis cos ity ▁of ▁blood . ▁Thus , ▁we ▁can ▁say ▁that ▁blood ▁is ▁a ▁she ar ▁thin ning ▁fluid , ▁i . e ., ▁vis cos ity ▁decre ases ▁with ▁increase ▁in ▁she ar ▁rate . ▁Bey ond ▁a ▁she ar ▁rate ▁of ▁about ▁ 1 0 0 s ^- 1 , ▁the ▁vis cos ity ▁is ▁nearly ▁constant ▁and ▁the ▁blood ▁behav es ▁like ▁a ▁Newton ian ▁fluid . ▁Blood ▁is ▁a ▁vis co el astic ▁material , ▁i . e ., ▁vis c ous ▁and ▁el astic ▁because ▁the ▁effective ▁vis cos ity ▁of ▁blood ▁not ▁only ▁depends ▁on ▁the ▁she ar ▁rate ▁but ▁also ▁on ▁the ▁history ▁of ▁she ar ▁rate . ▁It ▁is ▁also ▁important ▁to ▁note ▁that ▁the ▁normal ▁blood ▁flows ▁much ▁more ▁easily ▁compared ▁to ▁rig id ▁particles , ▁for ▁the ▁same ▁particle ▁volume ▁fraction . ▁This ▁is ▁due ▁to ▁the ▁fact ▁that ▁red ▁blood ▁cells ▁can ▁accommod ate ▁by ▁de form ing