Which action describes bending a body part?

Bending a body part is described as flexion, which involves decreasing the angle between two bones or body parts. When a joint is flexed, it's typically folding or bringing the body parts closer together. For example, when you bend your elbow or knee, you are flexing those joints. This action is essential in movements that require the bending or shortening of limbs, allowing for activities like reaching, walking, or lifting.

On the other hand, extension refers to straightening a body part, which would increase the angle at a joint. Ambulation describes the act of walking, while oliguria refers to a medical condition characterized by low urine output, and neither of these terms relates to the action of bending.