For example, the average resting heart rate should remain between 60 to 100 beats per minute, according to the National Institutes of Health. Without negative feedback loops, there would be little regulation of crucial physiological functions.or example, the average resting heart rate should remain between 60 to 100 beats per minute, according to the National Institutes of Health. Without negative feedback loops, there would be little regulation of crucial physiological functions.
Medical Definition of flexion. 1  1: a bending movement around a joint in a limb (as the knee or elbow) that decreases the angle between the bones of the limb at the jointâcompare extension 2. 2  2: a forward raising of the arm or leg by a movement at the shoulder or hip joint.
reÂ·flex. adj. 1. Physiology Being an involuntary action or response, such as a sneeze, blink, or hiccup. 2. Produced as an automatic response or reaction: reflex opposition to change.oun. 1. reflex-an automatic instinctive unlearned reaction to a stimulus. inborn reflex, innate reflex, instinctive reflex, physiological reaction, reflex action, reflex response, unconditioned reflex. accommodation reflex-reflex changes in the eyes that enable an object to be focused on the retina.