THE skin or integumentary breathing is defined as the process in which animals carry out gas exchange directly between their body surface and the environment.
Skin respiration occurs in animals that live in aquatic or moist environments.
The animals that present cutaneous breathing are the porifers, cnidarians, flatworms, nematodes, some annelids and amphibians.
In amphibians, skin breathing complements lung breathing. This is because in adulthood they have lungs.
Cutaneous breathing is effective for small animals with highly vascularized skin.
The process of cutaneous breathing takes place through diffusion.
Oxygen gas, in greater concentration in the external environment, tends to enter the interior of the animal's body, where it is in low concentration. Meanwhile, carbon dioxide does the opposite.
Learn more about hematosis, the gas exchange process.
Types of Skin Breathing
Direct Skin Breathing
It occurs without the participation of the circulatory system. Thus, cells below the lining epithelium exchange gases directly and reach deeper cell layers.
Example: Planarians
Indirect Skin Breathing
Occurs with the participation of the circulatory system. Just below the surface of the lining epithelium are blood vessels that capture and transport gases throughout the body.
Example: Annelids and amphibians.
Learn more, read also:
- amphibians
- annelids
- platyhelminths
- frogs
