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Phasmid (nematode)
Phasmids are unicellular sensilla in the lateral tail region of certain species of nematodes. They are similar in their structure to amphid sensilla, but smaller. Phasmid neurons were recently shown to function in modulation of chemorepulsion Chemorepulsion is the directional movement of a cell away from a substance. Of the two directional varieties of chemotaxis, chemoattraction has been studied to a much greater extent. Only recently have the key components of the chemorepulsive pathw ... behavior. References Nematode anatomy {{Nematode-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensilla
A sensillum (plural ''sensilla'') is an arthropod sensory organ protruding from the cuticle of exoskeleton, or sometimes lying within or beneath it. Sensilla appear as small hairs or pegs over an individual's body. Inside each sensillum there are two to four sensory neurons. These neurons, or receptors, gather information about environment the arthropod is in: * Chemoreceptors (i.e. trichoid, basionic, coeloconic, placodea) * Mechanoreceptors (e.g.: bristle sensilla, campaniform sensilla, hair plates, chordotonal neurons) * Thermoreceptors * Hygroreceptors Most sensilla are specially shaped according to the type of information they are gathering. In spiders, slit sensilla are used to detect substrate vibrations, while trichobothria are used to detect air-borne vibrations. Chemoreceptors Chemo-reception is one of the most dominant senses in the insect kingdom. Many arthropods use chemical signals to locate food, shelter and mates. Other invertebrates have similar sensory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broad range of environments. Less formally, they are categorized as Helminths, but are taxonomically classified along with Arthropod, arthropods, Tardigrade, tardigrades and other moulting animalia, animals in the clade Ecdysozoa, and unlike platyhelminthe, flatworms, have tubular digestion, digestive systems with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum. Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species described to date vary by author and may change rapidly over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphid
Amphids (Greek: ''amphi'', around, double) are innervated invaginations of cuticle in nematodes. They are usually found in the anterior (head) region of the animal, at the base of the lips. Amphids are the principal olfactosensory organs of nematodes. Each amphid is made up of 12 sensory neurons with ciliated dendrite Dendrites (from Greek δένδρον ''déndron'', "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the n ...s. References Nematode anatomy {{nematode-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuron
A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. Non-animals like plants and fungi do not have nerve cells. Neurons are typically classified into three types based on their function. Sensory neurons respond to stimuli such as touch, sound, or light that affect the cells of the sensory organs, and they send signals to the spinal cord or brain. Motor neurons receive signals from the brain and spinal cord to control everything from muscle contractions to glandular output. Interneurons connect neurons to other neurons within the same region of the brain or spinal cord. When multiple neurons are connected together, they form what is called a neural circuit. A typical neuron consists of a cell body (soma), dendrites, and a single axon. The soma is a compact structure, and the axon and dend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemorepulsion
Chemorepulsion is the directional movement of a cell away from a substance. Of the two directional varieties of chemotaxis, chemoattraction has been studied to a much greater extent. Only recently have the key components of the chemorepulsive pathway been elucidated.Vianello, F., E. Righi, et al. (2010). Methods for Quantitation of Leukocyte Chemotaxis and Fugetaxis. T-Cell Trafficking. F. M. Marelli-Berg and S. Nourshargh, Humana Press. 616: 115-124. The exact mechanism is still being investigated, and its constituents are currently being explored as likely candidates for immunotherapies.IMMUNOLOGY - CHAPTER ONE > INNATE (NON-SPECIFIC) IMMUNITY Gene Mayer, Ph.D. Immunology Section of Microbiology and Immunology On-line. University of South Carolina. History and etymology The mechanism of the chemorepulsion of immune cells was first acknowledged by medical researchers at the Massachusetts General Hospital in Boston in early 2002. The phenomenon was originally referred to as " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
