Name The Respiratory Organs of the Following: (a) Crab (b) Man (c) Leech (d) An Insect


Breathing is an essential function of life that enables living organisms to take in oxygen and expel carbon dioxide, which is vital for cellular respiration. This process of exchanging gases between an organism and its environment takes place through specialized respiratory organs that vary in structure and function across different species. In this article, we will identify the respiratory organs of four different organisms, namely a crab, a human, a leech, and an insect.

Respiratory Organs of Different Organisms

(a) Crab - Gills

Crabs are aquatic organisms that use gills to extract oxygen from water. The gills are located in the branchial chamber, which is a cavity located between the carapace (hard upper shell) and the soft abdomen of the crab. The gills are feathery structures that are well adapted to extracting oxygen from water. As water flows over the gills, oxygen diffuses from the water into the gill filaments, where it is then transported to the crab's circulatory system.

(b) Man - Lungs

Humans are air-breathing organisms that use lungs to extract oxygen from the air. The lungs are located within the thoracic cavity, which is protected by the ribcage. The lungs are spongy organs that are made up of millions of tiny air sacs called alveoli. When we inhale, air enters the lungs and fills the alveoli, where oxygen diffuses from the air into the capillaries that surround the alveoli. The oxygen is then transported to the body's cells via the circulatory system, while carbon dioxide is expelled from the body during exhalation.

(c) Leech - Skin

Leeches are aquatic and terrestrial organisms that use their skin to extract oxygen from the water or air. The skin of leeches is thin and moist, which allows for efficient gas exchange. Oxygen diffuses through the skin and into the leech's circulatory system, while carbon dioxide diffuses out of the body.

(d) Insect - Tracheae

Insects have a unique respiratory system that uses a network of tiny tubes called tracheae to deliver oxygen directly to the cells. The tracheae are connected to small openings on the insect's body called spiracles, which allow for air to enter and exit the body. The tracheae branch off into smaller tubes called tracheoles, which come into contact with the insect's cells. Oxygen diffuses from the tracheoles into the cells, while carbon dioxide diffuses out of the cells and into the tracheoles.


Breathing is a vital function of life that enables organisms to extract oxygen and remove carbon dioxide from their bodies. The respiratory organs of different organisms vary in structure and function, depending on their environment and physiological needs. In this article, we have identified the respiratory organs of a crab, a human, a leech, and an insect.

Updated on: 16-May-2023


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