“taste bud”的概念、定义、翻译、参考文献-科学参考

taste bud

Biology

A small sense organ in most vertebrates, specialized for the detection of taste. In terrestrial animals taste buds are concentrated on the upper surface of the tongue—the human tongue has 5000 to 10 000, found mostly on the sides of the papillae. Each taste bud contains a cluster of receptor cells (gustatory receptors) whose ends converge on a tiny opening, the taste pore. Microvilli project from the apical surface of the receptor cells into the taste pore to receive the substances (tastants) that elicit the taste stimulus. The receptor cells are surrounded by supporting cells and basal cells, which generate new receptor cells. Each receptor cell is specific for one of five classes of tastant: sweet, salt, bitter, sour, and umami (the latter is from the Japanese for ‘delicious’ and is a savoury or meaty taste evoked by certain amino acids and the flavour enhancer monosodium glutamate). Binding of a tastant with a receptor protein in a receptor cell causes the release of neurotransmitter onto associated sensory neurons, which transmit nerve impulses to the brain. The mechanism of signal transduction varies according to the type of tastant. For example, salty and some sour tastants bind to ionotropic receptors and cause the opening of ion channels that allow the influx of sodium ions, which leads to depolarization of the receptor cell, whereas some bitter tastants bind to G protein-coupled metabotropic receptors that stimulate intracellular signalling pathways, e.g. involving the release of calcium ions from stores.
In fishes the distinction between taste and smell is less clear; taste buds can be found in lips, gill rakers, the oral cavity, pharynx, oesophagus, and distributed over the surface of the body and on the fins. All provide information about the surrounding water or substrate. They also have receptors in olfactory pits on the head. Insects have taste receptors on their mouthparts and feet. These take the form of hollow hairlike projections of the cuticle (sensillae) inside which are the dendrites of several sensory cells.

单词	taste bud
释义	taste bud Biology A small sense organ in most vertebrates, specialized for the detection of taste. In terrestrial animals taste buds are concentrated on the upper surface of the tongue—the human tongue has 5000 to 10 000, found mostly on the sides of the papillae. Each taste bud contains a cluster of receptor cells (gustatory receptors) whose ends converge on a tiny opening, the taste pore. Microvilli project from the apical surface of the receptor cells into the taste pore to receive the substances (tastants) that elicit the taste stimulus. The receptor cells are surrounded by supporting cells and basal cells, which generate new receptor cells. Each receptor cell is specific for one of five classes of tastant: sweet, salt, bitter, sour, and umami (the latter is from the Japanese for ‘delicious’ and is a savoury or meaty taste evoked by certain amino acids and the flavour enhancer monosodium glutamate). Binding of a tastant with a receptor protein in a receptor cell causes the release of neurotransmitter onto associated sensory neurons, which transmit nerve impulses to the brain. The mechanism of signal transduction varies according to the type of tastant. For example, salty and some sour tastants bind to ionotropic receptors and cause the opening of ion channels that allow the influx of sodium ions, which leads to depolarization of the receptor cell, whereas some bitter tastants bind to G protein-coupled metabotropic receptors that stimulate intracellular signalling pathways, e.g. involving the release of calcium ions from stores. In fishes the distinction between taste and smell is less clear; taste buds can be found in lips, gill rakers, the oral cavity, pharynx, oesophagus, and distributed over the surface of the body and on the fins. All provide information about the surrounding water or substrate. They also have receptors in olfactory pits on the head. Insects have taste receptors on their mouthparts and feet. These take the form of hollow hairlike projections of the cuticle (sensillae) inside which are the dendrites of several sensory cells.
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