Fill in the blanks to complete the statement about thrombopo…

Fill in the blanks to complete the statement about thrombopoesis. The liver and kidneys produce [__1__] which stimulates production of [__2__].  These cells then duplicate their DNA but do not divide, becoming [__3__].  These new cells are too large to leave the bone marrow, so they sprout proplatelets that protrude through the [__4__] instead.  The proplatelets are sheared off by the passing blood to become [__5__].