A-delta fibers are a type of nerve fiber that transmit sensory information, particularly related to pain and temperature. They are classified as myelinated fibers, which means they have a protective sheath that allows for faster signal transmission. A-delta fibers are responsible for the sharp, immediate pain sensation that occurs after an injury, such as a cut or burn. These fibers are part of the peripheral nervous system and play a crucial role in the body's response to harmful stimuli. When activated, A-delta fibers send signals to the brain, alerting it to potential danger and prompting a quick reaction, such as withdrawing from the source of pain.