in endocrine signaling, a hormone is released into the bloodstream and dispersed all over the body. why are only certain cells able to respond to the signal?

Anurse is preparing to administer ampicillin 500 mg in 50 ml of dextrose 5% in water (d5w) to infuse over 15 min. the drop factor of the manual iv tubing is 10 gtt/ml. the nurse should set the manual iv infusion to deliver how many gtt/min? (round the answer to the nearest whole number. use a leading zero if it applies. do not use a trailing zero.)