The lateral antebrachial cutaneous nerve is a sensory nerve that arises from the musculocutaneous nerve in the upper arm. It primarily provides sensation to the skin on the lateral side of the forearm, helping to relay touch, temperature, and pain information from this area to the brain. This nerve plays a crucial role in the overall function of the peripheral nervous system. Damage or irritation to the lateral antebrachial cutaneous nerve can lead to numbness or tingling in the forearm, affecting a person's ability to feel sensations in that region.