Permeable walls - allow gases to pass through. Extensive blood supply - ensuring oxygen rich blood is taken away from the lungs and carbon dioxide rich blood is taken to the lungs. A large diffusion gradient - breathing ensures that the oxygen concentration in the alveoli is higher than in the capillaries so oxygen moves from the alveoli to the blood.
Carbon dioxide diffuses in the opposite direction. This is critical for maintaining the concentration gradients that make gas exchange possible. Essentially, carbon dioxide diffuses from an area of its higher concentration the blood to one of its lower lungs. Oxygen does the opposite. The excellent ventilation in the lungs makes this possible.
What are four ways the lungs are adapted to their function? May 16, Some adaptations are related to the alveoli, exercise, surface area, and ventilation. Explanation: Alveoli The alveoli are the location of gas exchange in the lungs. Related questions What is the significance of the fact that human tracheal cartilage rings are incomplete How is oxygen, carbon dioxide, and other waste gases exchanged in the lungs and body tissues?
What is the function of the lungs in connection with the circulatory system? Larger organisms have had to evolve specialized respiratory tissues, such as gills, lungs, and respiratory passages, accompanied by a complex circulatory system to transport oxygen throughout their entire body. For small multicellular organisms, diffusion across the outer membrane is sufficient to meet their oxygen needs.
Gas exchange by direct diffusion across surface membranes is efficient for organisms less than 1 mm in diameter. In simple organisms, such as cnidarians and flatworms, every cell in the body is close to the external environment.
Their cells are kept moist so that gases diffuse quickly via direct diffusion. The flat shape of these organisms increases the surface area for diffusion, ensuring that each cell within the body is close to the outer membrane surface and has access to oxygen.
If the flatworm had a cylindrical body, then the cells in the center would not be able to get oxygen. Respiration can occur using a variety of respiratory organs in different animals, including skin, gills, and tracheal systems.
There are various methods of gas exchange used by animals. As seen in mammals, air is taken in from the external environment to the lungs. Other animals, such as earthworms and amphibians, use their skin integument as a respiratory organ. A dense network of capillaries lies just below the skin, facilitating gas exchange between the external environment and the circulatory system. The respiratory surface must be kept moist in order for the gases to dissolve and diffuse across cell membranes.
Organisms that live in water also need a way to obtain oxygen. Oxygen dissolves in water, but at a lower concentration in comparison to the atmosphere, which has roughly 21 percent oxygen. Fish and many other aquatic organisms have evolved gills to take up the dissolved oxygen from water. Gills are thin tissue filaments that are highly branched and folded. When water passes over the gills, the dissolved oxygen in the water rapidly diffuses across the gills into the bloodstream.
The circulatory system can then carry the oxygenated blood to the other parts of the body. In animals that contain coelomic fluid instead of blood, oxygen diffuses across the gill surfaces into the coelomic fluid. Gills are found in mollusks, annelids, and crustaceans. Common carp : This common carp, like many other aquatic organisms, has gills that allow it to obtain oxygen from water. The folded surfaces of the gills provide a large surface area to ensure that fish obtain sufficient oxygen.
Diffusion is a process in which material travels from regions of high concentration to low concentration until equilibrium is reached.
In this case, blood with a low concentration of oxygen molecules circulates through the gills. The concentration of oxygen molecules in water is higher than the concentration of oxygen molecules in gills. As a result, oxygen molecules diffuse from water high concentration to blood low concentration.
Similarly, carbon dioxide molecules diffuse from the blood high concentration to water low concentration. Oxygen transport and gills : As water flows over the gills, oxygen is transferred to blood via the veins.
Insect respiration is independent of its circulatory system; therefore, the blood does not play a direct role in oxygen transport. Insects have a highly-specialized type of respiratory system called the tracheal system, which consists of a network of small tubes that carries oxygen to the entire body. The tracheal system, the most direct and efficient respiratory system in active animals, has tubes made of a polymeric material called chitin. Insect bodies have openings, called spiracles, along the thorax and abdomen.
These openings connect to the tubular network, allowing oxygen to pass into the body, regulating the diffusion of CO 2 and water vapor. Air enters and leaves the tracheal system through the spiracles.
Some insects can ventilate the tracheal system with body movements. Insect respiration : Insects perform respiration via a tracheal system, in which openings called spiracles allow oxygen to pass into the body. Birds and amphibians have different oxygen requirements than mammals, and as a result, different respiratory systems. Amphibians have evolved multiple ways of breathing. Young amphibians, like tadpoles, use gills to breathe, and they do not leave the water.
As the tadpole grows, the gills disappear and lungs grow though some amphibians retain gills for life. These lungs are primitive and are not as evolved as mammalian lungs.
Adult amphibians are lacking or have a reduced diaphragm, so breathing through the lungs is forced. The other means of breathing for amphibians is diffusion across the skin. To aid this diffusion, amphibian skin must remain moist. It has vascular tissues to make this gaseous exchange possible. This moist skin interface can be a detriment on land, but works well under water.
Birds are different from other vertebrates, with birds having relatively small lungs and nine air sacs that play an important role in respiration. The lungs of birds also do not have the capacity to inflate as birds lack a diaphragm and a pleural cavity.
Gas exchange in birds occurs between air capillaries and blood capillaries, rather than in alveoli. Flight poses a unique challenge with respect to breathing. Flying consumes a great amount of energy; therefore, birds require a lot of oxygen to aid their metabolic processes.
Birds have evolved a respiratory system that supplies them with the oxygen needed to sustain flight. Similar to mammals, birds have lungs, which are organs specialized for gas exchange.
Oxygenated air, taken in during inhalation, diffuses across the surface of the lungs into the bloodstream, and carbon dioxide diffuses from the blood into the lungs, and is then expelled during exhalation. The details of breathing between birds and mammals differ substantially.
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