Spiders do not have lungs or a respiratory system like humans do. Instead, they breathe through tiny openings in their abdomen called spiracles. These spiracles lead to a network of tubes called tracheae, which deliver oxygen directly to the spider's cells.

The exchange of gases in spiders occurs through diffusion, which is the process by which gases move from an area of high concentration to an area of low concentration. Oxygen from the air enters the spider's spiracles and diffuses through the tracheae, eventually reaching the spider's cells. Carbon dioxide, which is a waste product of respiration, diffuses in the opposite direction, from the spider's cells to the spiracles, and is then expelled into the air.

It's worth noting that different species of spiders have different respiratory systems, and some larger species may have modified respiratory structures to accommodate their size and oxygen needs.