We explain what animal respiration is and what this process consists of. Also, the types of animal respiration that exist and examples.
What is animal respiration?
When we speak of animal respiration, we refer to the metabolic mechanism of the living beings of animal Kingdom, consisting of an exchange of gases with the environment, in which oxygen (O2) is introduced to the body and carbon dioxide (CO2) is expelled. This process is common to all known animals, from the unicellular to the higher and, of course, also to the human being, although not through the same body systems, nor in the same vital means.
Breathing, in whatever way, consists of acquiring oxygen and eliminating carbon dioxide, since the first gas is vital to process sugars and obtain biochemical energy to live, and the second gas is a by-product of said reaction that must be eliminated as it is detrimental to the organism. So all animals do it: some straight out of the air, like humans and dogs; others through Waterlike fish and tadpoles.
Once oxygen enters the body from animal respiration, the circulatory system It is responsible for distributing it throughout the body, in order to feed the various biological tissues that need it. In that sense, systems are connected respiratory and cardiovascular, which can be very different depending on the species of animal to which we refer.
Types of animal respiration
There are various methods of breathing, according to the animal species and its mechanisms obtained over centuries of evolution. These mechanisms are:
- Skin respiration As the name implies, it takes place through the skin. Some animals such as annelids (such as earthworms) and amphibians (like frogs), especially those that live in humid environments, have a thin and specialized skin, capable of capturing the air or from the water the desired gases and transfer them directly to the capillary system (blood vessels), releasing the carbon dioxide in the same way.
- Branchial respiration. Typical of aquatic or underwater animals, that is, they never leave the water and obtain the oxygen they need to live from it. For this they have gills, complex organs with thin walls and abundant blood vessels, which are in perpetual contact with the liquid (unlike the lungs, which are inside the body) and covered with soft, fragile and porous tissues. As water passes through them, oxygen is filtered and carbon dioxide is released, so many fish must sleep in streams or constantly movement, to be able to breathe.
- Tracheal breathing. Typical of insects and arachnids. By trachea we mean a system of tubes that connect the inside of the animal with the outside, through holes called stigmata. The air penetrates through them and, as the tubes become narrower, oxygen enters the cells and hemolymph (the blood of insects), while carbon dioxide is discharged.
- Lung breathing Common to humans, mammals, birds and most reptiles And amphibians, this mode of respiration works in air only, and requires internal organs called lungs, which operate like an inflatable bag: it expands when air enters and deflates when it leaves. Inside there is a structure full of capillaries called alveoli, where gas exchange occurs. Being inside the body, the lungs connect to the outside through the trachea, which then connects to the nose or mouth, and which has a series of filters along the way to retain impurities from the air.