单项选择题
A．It is secreted by the kidneys into the bloodstream. B．It is hormone that prepares the body for emergencies. C．It is the only useful hormone produced in the body. D．It is essential to sustain lif
A．a signal sent by your brain B．the special function of the adrenal gland C．all stimulated parts of your body D．All of these
A．The adrenal gland is located on top of the kidney. B．Each kidney is composed of two adrenal glands. C．The medulla is inside the cortex. D．The cortex and the medulla have different functions.