TYPES OF RESPIRATION OF LIVING BEINGS - BIOLOGY - 2025

The types of respiration of living beings vary depending on the type of organism we are talking about and its physical characteristics. In general, living beings of the same family (plants, fungi, bacteria…) will share the same kind of respiration.

Respiration is one of the fundamental processes of all living beings. Through it, organisms are able to acquire the oxygen they need to convert food into energy. However, not all living things practice breathing in the same way.

Animals, however, are an exception. Within the animal kingdom, we can find several types of respiration depending on the organs that have developed for this purpose. Thus, there are animals with gills, others with lungs, and others that breathe through their own skin.

Types of respiration common to all living things

Although respiration in plants, animals, and bacteria occurs through different processes, all types of living things share some important characteristics. Specifically, your respiration can be divided into two clearly differentiated types: aerobic and anaerobic.

Aerobic respiration

Aerobic respiration is a way of extracting energy from nutrients through a complex process in which oxygen from the outside is used to oxidize food molecules, such as glucose.

In general, this type of respiration is typical of complex organisms, such as all eukaryotic organisms and some bacteria. Aerobic respiration occurs in the mitochondria.

In this process, in addition to energy, CO2 and water are also released.

Anaerobic respiration

Anaerobic respiration differs from the previous one mainly by the absence of external oxygen during the process. It is mainly used by some types of bacteria; and CO2 and ethyl alcohol are released. However, it should not be confused with fermentation.

Breathing in plants

Photosynthesis (left) and respiration (right). Image on the right taken from BBC

Plants also breathe. Although they produce oxygen through photosynthesis, they also need to exchange the CO2 they produce for oxygen from outside.

All parts of plants breathe: the stem, the roots, the leaves, and even the flowers. The parts that are in contact with the air absorb oxygen through small openings in the leaves (stomata) and the stem or trunk (lenticels).

However, despite the fact that plants can absorb oxygen through all its parts, their main respiratory organs are the leaves, which are also responsible for photosynthesis. Both processes occur simultaneously in the presence of sunlight.

In general, the leaves are responsible for two respiratory processes: exchanging carbon dioxide for oxygen, and releasing the water vapor that is produced in aerobic respiration to the environment.

The roots of the plant also need to breathe, so they absorb oxygen from the air pockets left in the ground.

Respiration in animals

It is in animals where we can find the greatest differences in the types of breathing they practice. Throughout evolutionary history, animals have developed different specialized organs that allowed them to adapt to the environment and breathe as efficiently as possible.

Depending on which is the main organ that the animal uses to absorb oxygen, we can find mainly four types of respiration: cutaneous respiration, tracheal respiration, gill respiration and lung respiration.

Skin respiration

Cutaneous respiration is the least complex type of animal respiration, since the organisms that practice it do not require any specialized organ to practice it. The exchange of oxygen and carbon dioxide occurs directly through the skin.

Normally, this type of respiration occurs in small animals, with very thin skin, and that therefore allows the passage of gases involved in respiration without any problem. Some of the animals that practice it are snails, toads and earthworms.

Tracheal breathing

Tracheal respiration is practiced by arthropods: insects, arachnids, crustaceans… It is characterized by the appearance of tubes, called tracheas, that connect with each other and with the outside. These tracheas are responsible for transporting oxygen to the cells of the animal.

The tracheas are connected to the outside through holes called spiracles, through which the exchange of oxygen and carbon dioxide takes place. One of the most curious characteristics of this type of breathing is that it does not require the intervention of any type of circulatory system.

Branchial breathing

Branchial respiration is the respiratory system used by aquatic animals. These types of organisms carry out the exchange of oxygen and carbon dioxide through organs called gills, which are capable of filtering the O2 that is dissolved in the water.

Once the oxygen is absorbed from the water, the gills pass it into the blood, which later transports it to all the cells and tissues of the animal's body. Once in cells, the mitochondria use oxygen for energy.

Due to the functioning of this system, animals that perform gill respiration require a circulatory system, so that oxygen reaches all the cells of their body.

Lung breathing

Pulmonary respiration is the most complex form of animal respiration, and is characteristic of mammals, reptiles, and birds. The most remarkable feature of this type of breathing is the appearance of specialized organs called lungs, which are responsible for the exchange of gases with the outside.

In humans, the respiratory system is divided into two parts: upper and lower.

• The upper respiratory system is made up of the nasal passages, nasal cavity, pharynx, and larynx.
• The lower respiratory system is made up of the trachea, bronchial tubes, bronchioles, and alveoli.

In humans, air passes through the nostrils and travels through the respiratory system until it reaches the bronchi, where the current is divided between the two lungs. Once in each lung, the air reaches the alveoli, which are responsible for exchanging carbon dioxide for oxygen.

References

1. "Types of Breathing" in: Estudioteca. Retrieved on: January 17, 2018 from Estudioteca: Estudioteca.net.
2. "Breathing in Living Beings" in: Investiciencias. Retrieved on: January 17, 2018 from Investiciencias: investiciencias.com.
3. "Respiration in Plants and Animals" in: Grade Stack. Retrieved on: January 17, 2018 from Grade Stack: gradestack.com.
4. "Respiration in Plants and Animals" in: Hunker. Retrieved on: January 17, 2018 from Hunker: hunker.com.