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.
Flexion and extension are movements that occur in the sagittal plane. They refer to increasing and decreasing the angle between two body parts: Flexion refers to a movement that decreases the angle between two body parts. Flexion at the elbow is decreasing the angle between the ulna and the humerus. When the knee flexes, the ankle moves closer to the buttock, and the angle between the femur and tibia gets smaller. Extension refers to a movement that increases the angle between two body parts.