Stinging Hair
A stinging plant or a plant with stinging hairs is a plant with hairs (trichomes) on its leaves or stems that are capable of injecting substances that cause pain or irritation. Other plants, such as opuntias, have hairs or spines that cause mechanical irritation, but do not inject chemicals. Stinging hairs occur particularly in the families Urticaceae, Loasaceae, Boraginaceae (subfamily Hydrophylloideae) and Euphorbiaceae. Such hairs have been shown to deter grazing mammals, but are no more effective against insect attack than non-stinging hairs. Many plants with stinging hairs have the word "nettle" in their English name, but may not be related to "true nettles" (the genus ''Urtica''). Though several unrelated families of plants have stinging hairs, their structure is generally similar. A solid base supports a single elongated cell with a brittle tip. When the tip is broken, the exposed sharp point penetrates the skin and pressure injects toxins. The precise chemicals invol ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Urtica Dioica38 Ies
''Urtica'' is a genus of flowering plants in the family Urticaceae. Many species have stinging hairs and may be called nettles or stinging nettles, although the latter name applies particularly to ''Urtica dioica''. ''Urtica'' species are food for the caterpillars of numerous Lepidoptera (butterflies and moths), such as the tortrix moth ''Syricoris lacunana'' and several Nymphalidae, such as ''Vanessa atalanta'', one of the red admiral butterflies. The generic name ''Urtica'' derives from the Latin for sting. Description ''Urtica'' species grow as annual plant, annuals or perennial herbaceous plants, rarely shrubs. They can reach, depending on the type, location and nutrient status, a height of . The perennial species have underground rhizomes. The green parts have stinging hairs. Their often quadrangular stems are unbranched or branched, erect, ascending or spreading. Most leaves and stalks are arranged across Alternate leaf, opposite sides of the stem. The leaf blades are ell ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and most abundant families of materials, existing as a compound of several minerals and as a synthetic product. Notable examples include fused quartz, fumed silica, silica gel, opal and aerogels. It is used in structural materials, microelectronics (as an Insulator (electricity), electrical insulator), and as components in the food and pharmaceutical industries. Structure In the majority of silicates, the silicon atom shows tetrahedral coordination geometry, tetrahedral coordination, with four oxygen atoms surrounding a central Si atomsee 3-D Unit Cell. Thus, SiO2 forms 3-dimensional network solids in which each silicon atom is covalently bonded in a tetrahedral manner to 4 oxygen atoms. In contrast, CO2 is a linear ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotransmitters are released from synaptic vesicles into the synaptic cleft where they are able to interact with neurotransmitter receptors on the target cell. The neurotransmitter's effect on the target cell is determined by the receptor it binds. Many neurotransmitters are synthesized from simple and plentiful precursors such as amino acids, which are readily available and often require a small number of biosynthetic steps for conversion. Neurotransmitters are essential to the function of complex neural systems. The exact number of unique neurotransmitters in humans is unknown, but more than 100 have been identified. Common neurotransmitters include glutamate, GABA, acetylcholine, glycine and norepinephrine. Mechanism and cycle Synthes ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described. Vertebrates comprise such groups as the following: * jawless fish, which include hagfish and lampreys * jawed vertebrates, which include: ** cartilaginous fish (sharks, rays, and ratfish) ** bony vertebrates, which include: *** ray-fins (the majority of living bony fish) *** lobe-fins, which include: **** coelacanths and lungfish **** tetrapods (limbed vertebrates) Extant vertebrates range in size from the frog species ''Paedophryne amauensis'', at as little as , to the blue whale, at up to . Vertebrates make up less than five percent of all described animal species; the rest are invertebrates, which lack vertebral columns. The vertebrates traditionally include the hagfish, which do no ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Laportea
''Laportea'' is a genus of plants in the family Urticaceae. They are herbaceous, either annual or perennial. Like many plants of the Urticaceae, they have stinging hairs. There are stinging and non-stinging hairs on the same plant. The genus was named after the French naturalist Francis de Laporte de Castelnau.Weddell, H. A. Chloris Andina. 1857''Essai d'une flore de la region alpine des Cordilleres de l'Amerique du Sud'' Vol. 1. Bertrand. Species , Kew's Plants of the World Online Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ... lists 36 species in the genus ''Laportea'': References * Urticaceae genera Taxa named by François-Louis Laporte, comte de Castelnau Taxonomy articles created by Polbot {{Urticaceae-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cnidoscolus Urens
''Cnidoscolus urens'' is a perennial, tropical American stinging herb of the family Euphorbiaceae, and is one of some 100 species belonging to the genus ''Cnidoscolus'' (Gk. knidē-nettle, skōlos-thorn, Latin urens-burning). The plant is locally known as 'bull nettle', 'spurge nettle', 'bringamosa' and 'mala mujer' (evil woman). This species has an erect stem and is herbaceous when young, turning woody with age and from 50 to 150 centimeters tall. Leaves are lobed and large, while the white flowers occur in cymes, producing a spiny 3-seeded capsule with seeds rich in fats and proteins, resembling those of '' Ricinus communis''. Its carunculate seeds are usually dispersed by ants (myrmecochory) attracted by the edible elaiosome. The entire plant is covered in stinging hairs, and has a native range covering Central and South America, being found in Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Peru and Venezuela. ''Cnidoscolus urens'' is monoecious and ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Urtica Parviflora
''Urtica'' is a genus of flowering plants in the family Urticaceae. Many species have stinging hairs and may be called nettles or stinging nettles, although the latter name applies particularly to ''Urtica dioica''. ''Urtica'' species are food for the caterpillars of numerous Lepidoptera (butterflies and moths), such as the tortrix moth ''Syricoris lacunana'' and several Nymphalidae, such as ''Vanessa atalanta'', one of the red admiral butterflies. The generic name ''Urtica'' derives from the Latin for sting. Description ''Urtica'' species grow as annuals or perennial herbaceous plants, rarely shrubs. They can reach, depending on the type, location and nutrient status, a height of . The perennial species have underground rhizomes. The green parts have stinging hairs. Their often quadrangular stems are unbranched or branched, erect, ascending or spreading. Most leaves and stalks are arranged across opposite sides of the stem. The leaf blades are elliptic, lanceolate, ovate ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Urtica Urens
''Urtica urens'', commonly known as annual nettle, dwarf nettle, small nettle, dog nettle, or burning nettle, is a herbaceous annual flowering plant species in the nettle family Urticaceae. It is native to Eurasia, including the Himalayan regions of Kalimpong, Darjeeling and Sikkim in India and can be found in North America, New Zealand and South Africa as an introduced species. It is reputed to sting more strongly than common nettle. Description Unlike the perennial and dioecious stinging nettle ''Urtica dioica'', ''Urtica urens'' is an annual plant, monoecious (with male and female flowers on the same plant) and generally much shorter. It can be distinguished from the stinging nettle by its more rounded leaves with coarser, deeper toothing and with the terminal tooth of similar length to the adjacent teeth. The lower leaves are shorter than their longer petioles and have stinging hairs only. Distribution The native distribution of ''Urtica urens'' includes most of Europe except ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Formic Acid
Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Esters, salts and the anion derived from formic acid are called formates. Industrially, formic acid is produced from methanol. Natural occurrence In nature, formic acid is found in most ants and in stingless bees of the genus ''Oxytrigona''. Wood ants from the genus ''Formica'' can spray formic acid on their prey or to defend the nest. The puss moth caterpillar (''Cerura vinula'') will spray it as well when threatened by predators. It is also found in the trichomes of stinging nettle (''Urtica dioica''). Apart from that, this acid is incorporated in many fruits such as pineapple (0.21mg per 100g), apple (2mg per 100g) and kiwi (1mg per 100g), as well as in many vegetables, namely onion (45mg per 100g), eggplant (1.34 mg per 100g) and, in ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Serotonin
Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vasoconstriction. Approximately 90% of the serotonin that the body produces is in the intestinal tract. Biochemically, the indoleamine molecule derives from the amino acid tryptophan, via the (rate-limiting) hydroxylation of the 5 position on the ring (forming the intermediate 5-hydroxytryptophan), and then decarboxylation to produce serotonin. Serotonin is primarily found in the enteric nervous system located in the gastrointestinal tract (GI tract). However, it is also produced in the central nervous system (CNS), specifically in the raphe nuclei located in the brainstem, Merkel cells located in the skin, pulmonary neuroendocrine cells and taste receptor cells in the tongue. Additionally, serotonin is stored in blood platelets and is ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Acetylcholine
Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Parts in the body that use or are affected by acetylcholine are referred to as cholinergic. Substances that increase or decrease the overall activity of the cholinergic system are called cholinergics and anticholinergics, respectively. Acetylcholine is the neurotransmitter used at the neuromuscular junction—in other words, it is the chemical that motor neurons of the nervous system release in order to activate muscles. This property means that drugs that affect cholinergic systems can have very dangerous effects ranging from paralysis to convulsions. Acetylcholine is also a neurotransmitter in the autonomic nervous system, both as an internal transmitter for the sympathetic nervous system and as the final product released by the parasymp ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Histamine
Histamine is an organic nitrogenous compound involved in local immune responses, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Since histamine was discovered in 1910, it has been considered a local hormone (autocoid) because it lacks the classic endocrine glands to secrete it; however, in recent years, histamine has been recognized as a central neurotransmitter. Histamine is involved in the inflammatory response and has a central role as a mediator of itching. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues. It consists of an imidazole ring attached to an ethylamine chain; under physiological conditions, the amino group of the side-chain is protonate ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |