All life on Earth has a common characteristic. Respiration is common for all living things in nature, including plants, animals and microorganisms. Even the most advanced creatures, human beings, cannot avoid breathing. No life on Earth can survive in space without air. Usually we divide respiration into two categories: aerobic respiration and anaerobic respiration. Through this article, we mainly understand the aerobic respiration of animals. In biological respiration, breathing modes mainly include: respiration of gill, lung respiration, skin membrane respiration.
Animals can be divided into aquatic, lactating, reptilian, amphibious and avian species by their different ways of breathing.
Aquatic animals usually breathe by gills. Strontium is an extension of the skin of aquatic animals specially used for gas exchange organ. All kinds of animals have different forms, but one common feature is a large surface area. For example, the strontium of the freshwater fish grows on the bow bow on both sides of the head, with four on the left and right, each of which contains two lines of bow filaments. The filaments on each carp are composed of sequential plates. Any animal that breathes with complaints can create its own stream of water so that its legs are constantly in contact with fresh water.
Fish carp is located on both sides of the pharynx, when the strontium cover is closed, the mouth is open, the water flows from the mouth to the pharynx, and then the mouth is closed, the carp cover is open, the mouth is contracted, the water flows through the carp, and the water flow out from the back edge of the cover. When the fish keep doing this in the water, people will mistake them for drinking but they are actually making water flow through the carp to breathe.
There are complex bronchial trees in the lungs of mammals. After entering the lungs, the bronchus branch again and again. At the end of the micronchus, the alveolar sacs are expanded. The appearance of alveoli greatly increased the total area of contact between the lungs and the gas. The total area of the alveoli in mammals is about 50to100 times the surface of the body.
Amphibians breathe oropharyngite, so what is oropharyngeal breathing?
Since amphibians don’t have thoracic galleries, they can’t rely on the expansion of thoracic galleries to breathe air into the lungs like other terrestrial vertebrates. They can only hold air in their mouths and swallow hard to let air enter the lungs. This type of breathing is called oropharyngeal breathing. Adult amphibians can also use their skin to help them breathe. Amphibian lung is relatively primitive, with a pair of cystic lungs, simple structure, only a few wrinkles in the lungs, small breathing area. The lack of capillaries in the lungs can not provide all the oxygen needed by the body, so it is necessary to use the capillaries under the skin to directly exchange gas with the air, called skin respiration.
The reptile lung, though as superficial as the amphibian lung, has complex compartments on the inner wall that divide the inner cavity into honeycomb chambers, greatly expanding the area of contact with the air. The structure of the lung varies greatly in different animals, the simplest form is still a sac, such as all kinds of snakes, lizards, turtles and crocodiles in the lung branch repeatedly, so that the whole lung is spongy; The front wall of the lung is honeycombs, called the respiratory part, and the back wall is smooth and extends a number of thin-waled gas meters, called the gas storage part. The adult reptile does not breathe with either carp or skin.
Birds have a special respiratory system, manifested in a very developed air sac and trachea. Air sacs are widely spread in the viscera, bone cavity and muscle, which makes birds in the process of inhalation and exhalation, the lungs have oxygen-rich airflow, in the inhalation and exhalation of the lung lobe can carry out gas exchange, is called double breathing, so as to improve the birds’ efficiency of respiration. After birds absorb the air through the nostrils, part of it is used for oxygen exchange directly in the lung, and the other part is stored in the air sac and then discharged through the lung. When birds fly, they can complete two gas exchanges with one inhalation in the lungs, which is the unique “double breathing” of birds.
All above illustrate how animals breathe.