Respiratory Organs in Animals

Introduction

Respiration is the process that releases energy through the breakdown of food in the body. Cell machinery is required for this breakdown of food. 

The steps in the process of respiration include oxygen intake (which is used to catabolize the food and for the proper functioning of vital organs), transport of oxygen and the removal of waste products, that is, carbon dioxide and water from the body. 

Respiration in animals is significant for the ecosystem as it provides the energy required to facilitate the better survival of organisms. It involves various metabolic reactions occurring simultaneously which is why it is said to be a complex process.The process of breathing is considered as a physical process whereas the process of respiration is a biochemical process. 

Different organisms have developed specialised respiratory organs that are adapted to different habitats. Respiration is a crucial process for the survival of an organism. There are some anaerobic organisms that go through this process also like some bacterias and some lower taxonomic organisms.

Exchange of Gas

Respiratory organs like lungs or gills are responsible for the actual exchange of gas. This exchange is based upon the principle of diffusion. Diffusion of gas means the process of gas moving from a region of higher concentration to a region of lower concentration. 

Respiratory Organs in Insects

In insects, the respiratory organs consist of a network of tubes known as tracheae that directly ventilate the tissues. Ventilation is the process of actively transporting air to the site of gas exchange. Similar to how arteries branch out into tiny capillaries in a closed circulatory system, the tubes divide and branch out into smaller tubes extending into all areas of the insect. 

Spiracles are tiny apertures found all over an insect’s body. The tracheae have apertures called spiracles. 

Diffusion is the only mode of gas exchange in tiny insects. Larger insects will aggressively breathe in order to fill the tubes with air. When aquatic insects are submerged, they must close their spiracles to prevent their tubes from flooding. Surprisingly, certain aquatic insects have specialised spiracles that can penetrate the submerged plants and gain access to the oxygen storage areas of those plants. 

Respiratory Organs in Mammals

The lungs are the most important organ in mammalian respiration. A suction-pump mechanism of inhalation and exhalation actively ventilates the lungs. The rib muscles and the diaphragm, a structure shaped like a dome-shaped floor directly beneath the lungs, are responsible for breathing.

The rib cage opens up and the diaphragm flattens and slides lower during inhalation. The air pressure inside the lungs decreases as the lungs expand into a greater space. The outside air rushes in due to the drop in air the pressure inside the lung.

Exhalation is the opposite of inhalation. The lungs contract while the diaphragm and rib muscles relax to their neutral state. Squeezing the lungs increases their air pressure, causing the air to escape.

The majority of mammals breathe through their noses. The air is warmed and moistened by inhaling through the nose. Cilia and mucus membranes filter the air, trapping dust and germs. The epiglottis, a little leaf-shaped flap at the rear of the throat, allows air to pass through. The epiglottis controls airflow into the windpipe and closes when food is swallowed to prevent food inhalation. It acts as a barrier between the lungs and the rest of the body.

Since gas exchange occurs in the capillaries, the alveoli and the capillary network have a strong working relationship. This gets the waste materials carried by the blood close enough to the fresh air for diffusion to occur. The waste is evacuated and the blood absorbs the oxygen. The haemoglobin in the blood binds the oxygen molecules together, similar to how a bus carries people. At any given time, each haemoglobin protein may transport four oxygen-carrying passengers. Carbon dioxide is eliminated as oxygen is given to the cells. The expelled water vapour and carbon dioxide are exhaled and inhalation begins again.

The respiratory organs in marine mammals are like their terrestrial counterparts. They breathe oxygen through their lungs, but there are a few peculiarities. 

They have evolved muscles or cartilaginous flaps to close their tracheas when submerged to prevent water from seeping into their airways. In addition to that, marine mammals may exchange up to 90% of their gas in a single breath, allowing them to take in as much oxygen as possible while expelling as much waste as possible.

Conclusion 

Respiration is a biological activity while breathing is a physical action. As a result, organisms have evolved particular respiratory organs suited to them that are required for the oxidation of food and the release of energy.

The respiratory system is all about exchanging gas with the environment. The respiratory system is the system in living organisms that takes in oxygen and releases carbon dioxide to meet energy demands. 

Different species have distinct respiratory organs. Gills are found in fish, lungs are used by mammals, birds , reptiles and amphibians breathe by exhaling through their skin.