Cell-to-Cell Connections and Messages

Practice: Cells in the adrenal medulla secrete a molecule called epinephrine into the bloodstream. Epinephrine travels through the body to affect a variety of organs, including the heart and gut. Which of the following describes the type of signaling exhibited by epinephrine secreted from the adrenal medulla?

Practice: ECL cells in the stomach secrete a molecule called histamine. That histamine then diffuses through the extracellular fluid to bind to and affect neighboring cells. Which of the following describes the type of signaling exhibited by histamine secreted secreted from ECL cells in the stomach?