What do both the motor neurons and hormones do in a negative feedback loop, such as the one in the diagram? ( You don't necessarily need to be able to read the words in the diagram to answer)

Adouble-blinded trial for a new indication is conducted under an ind comparing two (2) marketed drugs, at twice the approved prescribed doses. on day 2, subject 603 had difficulty breathing. although it was life-threatening initially, subject 603 was treated and discharged directly from the emergency department after complete recovery. on day 5, subject 20 had a headache, which led to hospitalization and required blood pressure lowering medications. these episodes cannot be explained on the basis of the pharmacological property of either drug or the subjects' medical histories. the investigator would submit an sae report for