Which system is responsible for providing supplemental oxygen in the event of cabin pressure loss on the CRJ 700?

The passenger oxygen system is specifically engineered to deploy supplemental oxygen to the passengers in the event of a cabin pressure loss. This system typically consists of oxygen masks that automatically drop down from the overhead compartments when there is a significant decompression in the cabin. The masks are connected to a source of oxygen that is designed to sustain passengers in an emergency situation, allowing them to breathe normally until the aircraft can descend to a safer altitude where breathable air is available.

This system is crucial for passenger safety, as rapid cabin decompression can lead to loss of consciousness due to hypoxia if not appropriately managed. The design and functionality of the passenger oxygen system ensure that, in the event of an emergency, oxygen is readily accessible and can be used immediately by those on board, thereby minimizing risk.

Other systems mentioned, such as the emergency lighting system, portable oxygen system, and cabin pressure system, serve different purposes that do not directly provide supplemental oxygen for passengers during a loss of cabin pressure. The emergency lighting system helps illuminate the cabin in emergencies for safe evacuation, the portable oxygen system is intended for crew use in specific situations, and the cabin pressure system maintains proper cabin conditions but is not responsible for providing supplemental oxygen.