Metamorphosis

Basic types of respiratory structures

Respiratory system
Certain marine organisms and terrestrial plants may release into the water, air, or soil inhibitory substances that discourage the growth of other organisms; well-known examples include the production of antibiotic substances by microorganisms. Custom made cages can also be used for this purpose as these mimic the natural habitat of a specific species in the best manner possible. If the airborne concentration is sufficiently high, the upper respiratory tract cannot remove all of the isocyanate or anhydride molecules, and pulmonary injury mainly edema results. There are around species in this sub-group, including turtles, tortoises and terrapins. Poisons of biological origin arthropods In arthropod: It is too weak to wrench open the sphincter and permit the evacuation of stomach contents Steinnon

Reptile Classification

Facts: History and Science Facts

International Union for Conservation of Nature. Retrieved 4 April Proteidae and its possible explanation". Natural History Museum, London.

Kluge Etymologisches Wörterbuch der deutschen Sprache , 23rd edition. Walter de Gruyter, p. Digitale Wörterbuch der deutschen Sprache. Ecosystems of the world: Subterranean Ecosystems , pp. Revue et nouvelles données sur la sensitivité a la lumiere et orientation non-visuelle chez Proteus anguinus, Calotriton asper et Desmognathus ochrophaeus Amphibiens urodeles hypogés.

Bulletin de la Société herpétologique de France , , pp. Journal of Physiology Paris. Développement et involution oculaire de Proteus anguinus Laurenti, Urodele cavernicole.

The effects of continuous darkness on cave ecology and cavernicolous evolution. How do cave animals cope with the food scarcity in caves? The olfaction in Proteus anguinus. Functional morphology of the inner ear and underwater audiograms of Proteus anguinus Amphibia, Urodela. Pflügers Arch 3 , suppl. Non-visual orientation and light-sensitivity in the blind cave salamander, Proteus anguinus Amphibia, Caudata. Societé Internationale de Biospéologie, pp.

Proteidae and relation with its habitat in the subterranean world". Journal of Thermal Biology. Reproductive biology and phylogeny of Urodela. Animal Biodiversity and Conservation. Proteus anguinus parkelj n. Bijdragen tot de Dierkunde. Archived from the original on Curiosities of Medical Experience 2nd ed. Retrieved 8 March TV Slovenia, Video tape. In Frank Meyer; et al.

Die Lurche und Kriechtiere Sachsen-Anhalts. Atlante degli anfibi e dei rettili del Veneto. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. Narodne novine in Croatian. Retrieved 7 June The A to Z of Slovenia. Retrieved from " https: Articles containing French-language text Articles with French-language external links Articles containing Slovene-language text Articles with Slovene-language external links Articles with German-language external links CS1 Croatian-language sources hr Wikipedia indefinitely move-protected pages Featured articles Articles with 'species' microformats Articles containing Italian-language text Articles containing Macedonian-language text Articles containing Montenegrin-language text Articles containing Serbian-language text Articles containing Bosnian-language text Articles containing Croatian-language text.

Views Read Edit View history. In other projects Wikimedia Commons Wikispecies. This page was last edited on 18 August , at By using this site, you agree to the Terms of Use and Privacy Policy. Olms in Postojna Cave , Slovenia.

Proteus Laurenti , Proteus anguinus Laurenti , Range north of the Adriatic Sea. Almost normally developed, although still small compared to other amphibians.

Covered by a thin layer of transparent skin, no eyelids. Regressed eye of White Proteus shows first of all immunolabelling for the red-sensitive cone opsin. The eye of Black Proteus has principal rods, red-sensitive cones and blue- or UV - sensitive cones. Wikispecies has information related to Proteus anguinus. Wikimedia Commons has media related to Proteus anguinus.

Basal caecilians such as Ichthyophis go through a metamorphosis in which aquatic larva transition into fossorial adults, which involves a loss of the lateral line. Thus, most caecilians do not undergo an anuran-like metamorphosis. Some fish, both bony fish Osteichthyes and jawless fish Agnatha , undergo metamorphosis. Fish metamorphosis is typically under strong control by the thyroid hormone. Examples among the non-bony fish include the lamprey. Among the bony fish, mechanisms are varied.

The salmon is diadromous , meaning that it changes from a freshwater to a saltwater lifestyle. Many species of flatfish begin their life bilaterally symmetrical , with an eye on either side of the body; but one eye moves to join the other side of the fish — which becomes the upper side — in the adult form.

The European eel has a number of metamorphoses, from the larval stage to the leptocephalus stage, then a quick metamorphosis to glass eel at the edge of the continental shelf eight days for the Japanese eel , two months at the border of fresh and salt water where the glass eel undergoes a quick metamorphosis into elver, then a long stage of growth followed by a more gradual metamorphosis to the migrating phase. In the pre-adult freshwater stage, the eel also has phenotypic plasticity because fish-eating eels develop very wide mandibles, making the head look blunt.

Leptocephali are common, occurring in all Elopomorpha tarpon- and eel-like fish. Most other bony fish undergo metamorphosis from embryo to larva fry and then to the juvenile stage during absorption of the yolk sac, because after that phase the individual needs to be able to feed for itself.

From Wikipedia, the free encyclopedia. This article is about the biological process. For other uses, see Metamorphosis disambiguation. This article needs additional citations for verification.

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An Outline of Entomology. Proceedings of the National Academy of Sciences. Retrieved June 11, Tiger Moths and Woolly Bears—behaviour, ecology, and evolution of the Arctiidae. Molecular Phylogenetics and Evolution. Moyle and Joseph J. This article's use of external links may not follow Wikipedia's policies or guidelines.

Please improve this article by removing excessive or inappropriate external links, and converting useful links where appropriate into footnote references. September Learn how and when to remove this template message. Retrieved from " https: A curious example of external gills is found in the male lungfish Lepidosiren.

At the time the male begins to care for the nest, a mass of vascular filaments a system of blood vessels develops as an outgrowth of the pelvic fins. The fish meets its own needs by refilling its lungs with air during periodic excursions to the water surface. When it returns to the nest, its pelvic-gill filaments are perfused with well-oxygenated blood, providing an oxygen supply for the eggs, which are more or less enveloped by the gill filaments.

It is theoretically possible for a skin that is well supplied with blood vessels to serve as a major or even the only respiratory surface. In terrestrial animals a moist integument also provides a major avenue of water loss. A number of fishes and amphibians rely on the skin for much of their respiratory exchange; hibernating frogs utilize the skin for practically all their gas exchanges. The lungs of vertebrates range from simple saclike structures found in the Dipnoi lungfishes to the complexly subdivided organs of mammals and birds.

An increasing subdivision of the airways and the development of greater surface area at the exchange surfaces appear to be the general evolutionary trend among the higher vertebrates.

In the embryo, lungs develop as an outgrowth of the forward portion of the gut. The lung proper is connected to the outside through a series of tubes; the main tube, known as the trachea windpipe , exits in the throat through a controllable orifice, the glottis.

At the other end the trachea subdivides into secondary tubes bronchi , in varying degree among different vertebrate groups. The trachea of amphibians is not divided into secondary tubes but ends abruptly at the lungs. The relatively simple lungs of frogs are subdivided by incomplete walls septa , and between the larger septa are secondary septa that surround the air spaces where gas exchange occurs. The diameter of these air spaces alveoli in lower vertebrates is larger than in mammals: The alveolus in the frog is about 10 times the diameter of the human alveolus.

The smaller alveoli in mammals are associated with a greater surface for gas exchange: An important characteristic of lungs is their elasticity. An elastic material is one that tends to return to its initial state after the removal of a deforming force. Elastic tissues behave like springs.

As the lungs are inflated, there is an accompanying increase in the energy stored within the elastic tissues of the lungs, just as energy is stored in a stretched rubber band. The conversion of this stored, or potential, energy into kinetic, or active, energy during the deflation process supplies part of the force needed for the expulsion of gases. A portion of the energy put into expansion is thus recovered during deflation. The elastic properties of the lungs have been studied by inflating them with air or liquid and measuring the resulting pressures.

Muscular effort supplies the motive power for expanding the lungs, and this is translated into the pressure required to produce lung inflation. It must be great enough to overcome 1 the elasticity of the lung and its surface lining; 2 the frictional resistance of the lungs; 3 the elasticity of the thorax or thoraco-abdominal cavity; 4 frictional resistance in the body-wall structures; 5 resistance inherent in the contracting muscles; and 6 the airway resistance.

The laboured breathing of the asthmatic is an example of the added muscular effort necessary to achieve adequate lung inflation when airway resistance is high, owing to narrowing of the tubes of the airways. Studies of the pressure—volume relationship of lungs filled with salt solution or air have shown that the pressure required to inflate the lungs to a given volume is less when the lungs are filled with liquid than when they are filled with air.

The differences in the two circumstances have been thought to result from the nature of the environment-alveolar interface, that interface being liquid—liquid in the fluid-filled lung and gas—liquid in the air-filled lung. In the case of the latter, the pressure—volume relationship represents the combined effects of the elastic properties of the lung wall plus the surface tension of the film, or surface coating, lining the lungs.

Surface tension is the property, resulting from molecular forces, that exists in the surface film of all liquids and tends to contract the volume into a form with the least surface area; the particles in the surface are inwardly attracted, thus resulting in tension. Surface tension is nearly zero in the fluid-filled lung.

The alveoli of the lungs are elastic bodies of nonuniform size. If their surfaces had a uniform surface tension, small alveoli would tend to collapse into large ones. The result in the lungs would be an unstable condition in which some alveoli would collapse and others would overexpand. This does not normally occur in the lung because of the properties of its surface coating surfactant , a complex substance composed of lipid and protein.

Surfactant causes the surface tension to change in a nonlinear way with changes in surface area. As a result, when the lungs fill with air, the surface tensions of the inflated alveoli are less than those of the relatively undistended alveoli.

This results in a stabilization of alveoli of differing sizes and prevents the emptying of small alveoli into larger ones. It has been suggested that compression wrinkles of the surface coating and attractive forces between adjacent wrinkles inhibit expansion.

Surfactants have been reported to be present in the lungs of birds, reptiles, and amphibians. We welcome suggested improvements to any of our articles. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind. Your contribution may be further edited by our staff, and its publication is subject to our final approval. Unfortunately, our editorial approach may not be able to accommodate all contributions. Our editors will review what you've submitted, and if it meets our criteria, we'll add it to the article.

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Next page Dynamics of vertebrate respiratory mechanisms. Learn More in these related Britannica articles: Closely coupled with the circulatory system is the ventilatory breathing apparatus, the lungs and associated structures. Ventilation in mammals is unique. The lungs themselves are less efficient than those of birds, for air movement consists of an ebb and flow, rather than a….

Gas exchange generally takes place through the skin, but it may occur through gill filaments in some polychaetes or through the rectum of aquatic oligochaetes. Although oxygen may be transported directly in the blood, it is usually carried by a respiratory pigment, either….

The respiratory system consists of longitudinal tracheal trunks that branch internally and communicate with the external air through ten pairs of holes called spiracles. Respiration under water presents special problems. Young aquatic nymphs may respire exclusively through the thin body wall.

The respiratory pathway is concerned principally with the gaseous waste products of metabolism carbon dioxide and ammonia , which move to the external environment by diffusing from the cells of origin. In invertebrate and vertebrate members of the animal kingdom, transport is by means….

More About Respiratory system 13 references found in Britannica articles Assorted References biochemical basis in circulatory system In circulatory system: Blood excretory function In excretion: Respiratory system animal arachnids In arachnid: Respiration spiders In spider: Respiration affected by atmospheric pressure In biosphere: Atmospheric pressure annelids In annelid: Respiratory system arthropods In arthropod: Respiratory system cetaceans In cetacean: Respiration comparative description of vertebrates In human digestive system: Evolutionary development crustaceans In crustacean: The respiratory system View More.

Articles from Britannica Encyclopedias for elementary and high school students. Help us improve this article! Contact our editors with your feedback. Introduction The gases in the environment Basic types of respiratory structures Respiratory organs of invertebrates Trachea Gills of invertebrates Respiratory organs of vertebrates The gills The lung Dynamics of vertebrate respiratory mechanisms Fishes Amphibians Reptiles Birds Mammals.

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What Is a Reptile?