Which nerves are depolarized first and give off a tingly feeling?

The correct response is related to AB fibers, which are responsible for transmitting sensory information, particularly those sensations that include light touch and vibration. When AB fibers are depolarized, they can create a tingling sensation, often described as a "pins and needles" feeling. This is due to their larger diameter and faster conduction velocity compared to other types of nerve fibers.

AB fibers are myelinated, which allows them to conduct impulses more efficiently. When electrical stimulation is applied, these fibers respond first because they can reach the threshold for depolarization quickly, often before other types of fibers have the chance to respond. This phenomenon explains why sensations such as tingling can often be experienced before discomfort or pain from other nerve types occurs.

In contrast, A-Delta and C fibers, which can also contribute to sensory perception, typically transmit pain and temperature sensations rather than light touch or tingling feelings. Motor fibers are involved in muscle contraction and do not contribute to sensory experiences. Ad fibers are another designation for A-Delta fibers, and C fibers are unmyelinated, slower-conducting fibers. Together, they are less likely to produce a tingling sensation than AB fibers, which are specifically tuned to convey more light and tactile sensations rapidly.