When Arizona Robbins pulls out of surgery and needs to sit down for a minute, she's shown to have an elaborate hair-do with lots of braids. Later that day, she runs into the efficiency evaluator, and suddenly Arizona is wearing a ponytail.
When Kepner drills Edwards on the statuses of the patients in the E.R. and the pan to show the board. It shows that every character has a patient and it also lists Kepner as the nurse for an MVC.
Anything below the waist in the OR is not considered in the sterile field, so when Alex bent down to stab Arizona's foot, he would have been considered contaminated and have to re-scrub.
When April asks Edwards about any updates to the ER, the board is shown that a Whiting, A. is both the primary nurse to patient 5 and is also patient 6 themself.