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.
For the vertebral column, flexion (anterior flexion) is an anterior (forward) bending of the neck or body, while extension involves a posterior-directed motion, such as straightening from a flexed position or bending backward. Lateral flexion is the bending of the neck or body toward the right or left side.