Final answer:
A partial rebreather mask looks like a face mask with a bag, or reservoir bag, attached to it, used for oxygen therapy by allowing patients to rebreathe some of their exhaled air along with supplemental oxygen.
Step-by-step explanation:
A partial rebreather mask looks like a face mask with a bag attached to it. This type of mask is used in medical settings to deliver oxygen therapy to patients. The bag, often referred to as a reservoir bag, is attached to the bottom of the mask, and it partially fills with a mixture of exhaled carbon dioxide and supplementary oxygen from a source. During inhalation, the patient breathes in oxygen from the bag, preserving some of the exhaled gases to reduce the loss of heat and moisture.
Partial rebreather masks are different from non-rebreather masks, which have a one-way valve that prevents exhaled air from returning to the bag. They are also distinct from continuous positive airway pressure (CPAP) devices and equipment used by scuba divers or firefighters, which serve very different purposes and functions.