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Tracheole
Tracheole (trā'kē-ōl') is a fine respiratory tube of the trachea of an insect or a spider, part of the respiratory system. Tracheoles are about 1 µm in diameter, and they convey oxygen to cells while providing a means for carbon dioxide to escape. Tracheoles branch from the larger tracheae (which can be several mm in diameter) much like capillaries branch from arteries, or twigs from branches of a tree. This increases the surface area for gas exchange in the insect. Areas of intense metabolic activity, such as the digestive tract and flight muscles, have very dense aggregations of tracheoles. Though usually closely associated with cells, tracheoles physically penetrate only the flight muscle cells which have the highest oxygen demands. Unlike the larger tracheae which are derived of ectodermal The ectoderm is one of the three primary germ layers formed in early embryonic development. It is the outermost layer, and is superficial to the mesoderm (the middle laye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invertebrate Trachea
The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. The trachea is formed by a number of horseshoe-shaped rings, joined together vertically by overlying ligaments, and by the trachealis muscle at their ends. The epiglottis closes the opening to the larynx during swallowing. The trachea begins to form in the second month of embryo development, becoming longer and more fixed in its position over time. It is epithelium lined with column-shaped cells that have hair-like extensions called cilia, with scattered goblet cells that produce protective mucins. The trachea can be affected by inflammation or infection, usually as a result of a viral illness affecting other parts of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. Their blood is not totally contained in vessels; some circulates in an open cavity known as the haemocoel. Insects are the most diverse group of animals; they include more than a million described species and represent more than half of all known living organisms. The total number of extant species is estimated at between six and ten million; In: potentially over 90% of the animal life forms on Earth are insects. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, which are dominated by another arthropod group, crustaceans, which recent research has indicated insects are nested within. Nearly all insects hatch f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiratory System Of Insects
An insect's respiratory system is the system with which it introduces respiratory gases to its interior and performs gas exchange. Air enters the respiratory systems of insects through a series of external openings called spiracles. These external openings, which act as muscular valves in some insects, lead to the internal respiratory system, a densely networked array of tubes called tracheae. This network of transverse and longitudinal tracheae equalizes pressure throughout the system. It is responsible for delivering sufficient oxygen (O2) to all cells of the body and for removing carbon dioxide (CO2) that is produced as a waste product of cellular respiration. The respiratory system of insects (and many other arthropods) is separate from the circulatory system. Structure of the spiracle Insects have spiracles on their exoskeletons to allow air to enter the trachea. In insects, the tracheal tubes primarily deliver oxygen directly into the insects' tissues. The spiracle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naturalis Biodiversity Center - RMNH
Naturalis Biodiversity Center ( nl, Nederlands Centrum voor Biodiversiteit Naturalis) is a national museum of natural history and a research center on biodiversity in Leiden, Netherlands. It was named the European Museum of the Year 2021. Although its current name and organization are relatively recent, the history of Naturalis can be traced back to the early 1800s. Its collection includes approximately 42 million specimens, making it one of the largest natural history collections in the world. History The beginnings of Naturalis go back to the creation of the Rijksmuseum van Natuurlijke Historie (abbreviated RMNH, National Museum of Natural History) by Dutch King William I on August 9, 1820. In 1878, the geological and mineralogical collections of the museum were split off into a separate museum, remaining distinct until the merger of the Rijksmuseum van Natuurlijke Historie with the Rijksmuseum van Geologie en Mineralogie (abbreviated RGM) in 1984, to form the Nationaal N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spider
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectodermal
The ectoderm is one of the three primary germ layers formed in early embryonic development. It is the outermost layer, and is superficial to the mesoderm (the middle layer) and endoderm (the innermost layer). It emerges and originates from the outer layer of germ cells. The word ectoderm comes from the Greek ''ektos'' meaning "outside", and ''derma'' meaning "skin".Gilbert, Scott F. Developmental Biology. 9th ed. Sunderland, MA: Sinauer Associates, 2010: 333-370. Print. Generally speaking, the ectoderm differentiates to form epithelial and neural tissues (spinal cord, peripheral nerves and brain). This includes the skin, linings of the mouth, anus, nostrils, sweat glands, hair and nails, and tooth enamel. Other types of epithelium are derived from the endoderm. In vertebrate embryos, the ectoderm can be divided into two parts: the dorsal surface ectoderm also known as the external ectoderm, and the neural plate, which invaginates to form the neural tube and neural crest. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
