Final answer:
A lancet is the device used to make small punctures in the skin, typically for blood sampling.
Step-by-step explanation:
The device used to puncture the finger or heel is commonly known as a lancet. Lancets are small medical tools designed with a sharp point that, when applied with force to an area approximately the size of its sharp end, are capable of breaking the skin. This tool is frequently used for blood glucose testing or other medical tests that require a small blood sample. The figure references provided compare the action of a lancet to being poked with a finger, illustrating how the application of the same force over a smaller area increases pressure, allowing the lancet to penetrate the skin.