Anything physiological has to do with the body and its systems. You might notice that your physiological response to a scary movie includes your heart beating faster and your hands getting sweaty.
You know that the root word of physiological is phys, which refers to the body (think of those phys. ed. classes you panted through). That root comes from the Greek word for nature. Add the suffix ology, which means "the study of" (see where we're going?), and finally, tack on that little ical. Ta-taa! You have turned the root into an adjective to describe the way your body works. Let's get physiological!