Comparative anatomy

The integumentary system is responsible for protection and maintaining body heat. It includes the skin, hair, nails, feathers, scales, etc. So it works differently for each organism. We are looking at the systems of a worm, frog, crawfish, and rat.

         

         

Earthworm

The worm’s integumentary system is necessary for many of the worm’s necessary functions. Worms don’t have a nose or lungs, and their mouth is linked only with their digestive system. So how do they brebathe? Through their skin! Oxygen is sent to their blood by being absorbed through their skin, and allowing it to diffuse into their body.

 Is that why their slimy? Water? Nope, they actually produce a special mucus from glands in its skin, which serves to allow as a filter allowing only certain things to enter the body.

Worms don’t have eyes either, so how do they see? They have sensors in their head that detect how much light, is in an area, so they know if they’re in danger or not. How do they know where they’re going? They don’t! Frankly they don’t need to, as long as they're in a dark wet place they can eat and poop in peace.

Crayfish

The crayfish's integumentary system differs from the earthworm in many ways. They have an exoskeleton, which means their skeleton is on the outside of their body. You might think having an exoskeleton might be a flawless advantage, but when it sheds it leaves the crayfish vulnerable to pretty much anything, and because the insides of a crayfish are so soft, it is defenseless until their exoskeleton grows back.

They also don't have a mouth, they have gills, but ill get more into that later, as it is part of the circulatory system more than the integumentary system. 

Frog

The frog has an integumentary system similar to a worms. Their skin is extremely thin, and colorful. It is water permeable, which means water can pass through their skin. In other words, they drink through their skin, and they also produce a mucus. The mucus serves to keep the skin moist, and exchange gasses as well as water. Some also have poison glands that are used as protection from predators.

Frogs can change the color of their skin which is useful for defense (camoflauge). It also controls body temperature, to maintain homeostasis.

Rat