Like other fish, sharks “breathe” through their gills, which are respiratory organs akin to our lungs. As water passes over the gill’s membranes, tiny blood vessels extract oxygen from the water. Carbon dioxide waste also passes from the shark’s blood and out of its body through the gill tissue.

What is the pathway of water through a shark's respiratory system?

Water enters the gill chambers through the mouth or spiracles and exits through the gill slits. In the past, it was assumed that all sharks must swim to move water into their mouth and over their gills to respire. We now know that sharks can respire by pumping water over their gills by opening and closing their mouths.

How does a Dolphins respiratory system work?

Whales and dolphins are mammals and breathe air into their lungs, just like we do. … They breathe through nostrils, called a blowhole, located right on top of their heads. This allows them to take breaths by exposing just the top of their heads to the air while they are swimming or resting under the water.