|
Chordotonal Organ
Chordotonal organs are stretch receptor organs found only in insects and crustaceans. They are located at most joints and are made up of clusters of scolopidia that either directly or indirectly connect two joints and sense their movements relative to one another. They can have both Exteroception, extero- and Proprioception, proprioceptive functions, for example sensing auditory stimuli or leg movement. The word was coined by Vitus Graber in 1882, though he interpreted them as being stretched between two points like a string, sensing vibrations through resonance. Structure Chordotonal organs can be composed of a single Scolopidia, scolopidium with only a single sensory, bipolar neuron (such as the Tympanal organ, tympanal ear of a notodontid moth), or up to several thousand scolopidia, each equipped with up to four sensory neurons (as in the mosquito Johnston's organ). The bipolar sensory neurons each have an apical dendritic structure with a cilium densely packed with microtubu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stretch Receptor
Stretch receptors are mechanoreceptors responsive to distention of various organs and muscles, and are neurologically linked to the Medulla oblongata, medulla in the brain stem via Afferent nerve fiber, afferent nerve fibers. Examples include stretch receptors in the arm and leg muscles and tendons, in the heart, in the colon wall, and in the lungs. Stretch receptors are also found around the carotid artery, where they monitor blood pressure and stimulate the release of antidiuretic hormone (vasopressin, ADH) from the posterior pituitary gland. Types include: * Golgi organ * Muscle spindle, sensory receptors within the belly of a muscle, which primarily detect changes in the length of this muscle * Pulmonary stretch receptors, mechanoreceptors found in the lungs * Chordotonal organ, in insects See also * Stretch sensor * Carotid sinus * Aortic arch * Mechanoreceptor {{biology-stub Sensory receptors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle Spindle
Muscle spindles are stretch receptors within the body of a skeletal muscle that primarily detect changes in the length of the muscle. They convey length information to the central nervous system via afferent nerve fibers. This information can be processed by the brain as proprioception. The responses of muscle spindles to changes in length also play an important role in regulating the contraction of muscles, for example, by activating motor neurons via the stretch reflex to resist muscle stretch. The muscle spindle has both sensory and motor components. * Sensory information conveyed by primary type Ia sensory fibers which spiral around muscle fibres within the spindle, and secondary type II sensory fibers * Activation of muscle fibres within the spindle by up to a dozen gamma motor neurons and to a lesser extent by one or two beta motor neurons ''.'' Structure Muscle spindles are found within the belly of a skeletal muscle. Muscle spindles are fusiform (spindle-shaped), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod Anatomy
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an exoskeleton with a cuticle made of chitin, often mineralised with calcium carbonate, a body with differentiated ( metameric) segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They form an extremely diverse group of up to ten million species. Haemolymph is the analogue of blood for most arthropods. An arthropod has an open circulatory system, with a body cavity called a haemocoel through which haemolymph circulates to the interior organs. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. They have ladder-like nervous systems, with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, and their brains are formed by fusi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford University Press
Oxford University Press (OUP) is the publishing house of the University of Oxford. It is the largest university press in the world. Its first book was printed in Oxford in 1478, with the Press officially granted the legal right to print books by decree in 1586. It is the second-oldest university press after Cambridge University Press, which was founded in 1534. It is a department of the University of Oxford. It is governed by a group of 15 academics, the Delegates of the Press, appointed by the Vice Chancellor, vice-chancellor of the University of Oxford. The Delegates of the Press are led by the Secretary to the Delegates, who serves as OUP's chief executive and as its major representative on other university bodies. Oxford University Press has had a similar governance structure since the 17th century. The press is located on Walton Street, Oxford, Walton Street, Oxford, opposite Somerville College, Oxford, Somerville College, in the inner suburb of Jericho, Oxford, Jericho. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subgenual Organ
The subgenual organ is an organ in insects that is involved in the perception of sound. The name (Latin ''sub: "''below" and ''genus: "''knee") refers to the location of the organ just below the knee in the tibia of all legs in most insects. The function of the organ is performed by aggregations of scolopidia, the unit mechanoreceptor in invertebrates. The organ is thought to be an evolutionary artifact of ancestral insects who used their legs to detect vibrations in the underlying substrate. The anatomy and innervation of the organ is highly variable between species. However, the organ may be sensitive enough to detect less than 1 nm of displacement in the ground, and sometimes airborne sound waves. The sensitivity of the organ varies from species to species; in Orthoptera, Hymenoptera and Lepidoptera, sensitivity is on the order of one (or greater) kilohertz, while in Hemiptera sensitivity reaches only a few hundred hertz. Characteristics within orders * Lepidoptera and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crista Acustica
Crista acustica (also Siebold's organ, or crista acoustica) is a part of the hearing organ (tibial organ) in some insects (e.g. grasshoppers, crickets, katydids). It is a collection of sensory cells that form a crest (hence the name) on top of the hollow tube (the foreleg trachea) behind the hearing membrane (tympanum) on the legs of the insect. The crista acustica is a transition from the intermedia organ (from the midline to the periphery), together which compose the tibial hearing organ (as opposed to the tympanal hearing organ). The crista acustica is one of three fiddle-string-like organs or chordotonal organ in insects: the others are the intermediate organ and the supratympanal organ/subgenual organ. These chordotonal organs are actually collections of sensory cells sensitive to vibration (these cells are called scolopidia cells). Their cells are attached to the tube in the legs of the insects (the trachea, "''trah-key-ah''"). So when the tube vibrates, the cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femoral Chordotonal Organ
The femoral chordotonal organ is a group of Mechanosensation, mechanosensory neurons found in an insect leg (Figure 1) that detects the movements and the position of the femur/tibia joint. It is thought to function as a Proprioception, proprioceptor that is critical for precise control of leg position by sending the information regarding the femur/tibia joint to the motor circuits in the ventral nerve cord and the brain Structure The Soma (biology), cell bodies of the femoral chordotonal neurons are generally located in the proximal femur, and their dendrites are mechanically coupled to the tibia through different types of tendons. In ''Drosophila'', where it is possible to Genetics, genetically identify different subtypes of femoral chordotonal neurons, the neurons can be divided into three subtypes based on their axonal projection pattern into the ventral nerve cord (Figure 2). The axons of the club neurons project to the center of the ventral nerve cord and form a bundle that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halteres
''Halteres'' (; singular ''halter'' or ''haltere'') (from , hand-held weights to give an impetus in leaping) are a pair of small club-shaped organs on the body of two Order (biology), orders of flying insects that provide information about body rotations during flight. Insects of the large order Diptera (flies) have halteres which evolved from a pair of ancestral hindwings, while males of the much smaller order Strepsiptera (stylops)Merriam-Webster: stylops broadly: an insect of the order Strepsiptera/ref> have halteres which evolved from a pair of ancestral forewings. Halteres oscillate rapidly along with the wings and operate like vibrating structure gyroscopes: any rotation of the plane of oscillation causes a force on the vibrating halteres by the Coriolis effect. The insect detects this force with sensory organs called campaniform sensilla and chordotonal organs located at the base of the halteres and uses this information to interpret and correct its position in space. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipterans
Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced mechanosensory organs known as halteres, which act as high-speed sensors of rotational movement and allow dipterans to perform advanced aerobatics. Diptera is a large order containing more than 150,000 species including horse-flies, crane flies, hoverflies, mosquitoes and others. Flies have a mobile head, with a pair of large compound eyes, and mouthparts designed for piercing and sucking (mosquitoes, black flies and robber flies), or for lapping and sucking in the other groups. Their wing arrangement gives them great manoeuvrability in flight, and claws and pads on their feet enable them to cling to smooth surfaces. Flies undergo complete metamorphosis; the eggs are often laid on the larval food-source and the larvae, which lack true lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beetle
Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 described species, is the largest of all orders, constituting almost 40% of described arthropods and 25% of all known animal species; new species are discovered frequently, with estimates suggesting that there are between 0.9 and 2.1 million total species. However, the number of beetle species is challenged by the number of species in Fly, dipterans (flies) and hymenopterans (wasps). Found in almost every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles often feed on plants and fungi, break down animal and plant debris, and eat other invertebrates. Some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae (ladybirds or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subgenual Organ
The subgenual organ is an organ in insects that is involved in the perception of sound. The name (Latin ''sub: "''below" and ''genus: "''knee") refers to the location of the organ just below the knee in the tibia of all legs in most insects. The function of the organ is performed by aggregations of scolopidia, the unit mechanoreceptor in invertebrates. The organ is thought to be an evolutionary artifact of ancestral insects who used their legs to detect vibrations in the underlying substrate. The anatomy and innervation of the organ is highly variable between species. However, the organ may be sensitive enough to detect less than 1 nm of displacement in the ground, and sometimes airborne sound waves. The sensitivity of the organ varies from species to species; in Orthoptera, Hymenoptera and Lepidoptera, sensitivity is on the order of one (or greater) kilohertz, while in Hemiptera sensitivity reaches only a few hundred hertz. Characteristics within orders * Lepidoptera and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hymenoptera
Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typically have a special ovipositor for inserting eggs into hosts or places that are otherwise inaccessible. This ovipositor is often modified into a stinger. The young develop through holometabolism (complete metamorphosis)—that is, they have a wormlike larval stage and an inactive pupal stage before they reach adulthood. Etymology The name Hymenoptera refers to the wings of the insects, but the original derivation is ambiguous. All references agree that the derivation involves the Ancient Greek πτερόν (''pteron'') for wing. The Ancient Greek ὑμήν (''hymen'') for membrane provides a plausible etymology for the term because species in this order have membranous wings. However, a key characteristic of this order is that the hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
