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Squid Giant Synapse
The squid giant synapse is a chemical synapse found in squid. It is the largest chemical junction in nature. Anatomy The squid giant synapse (Fig 1) was first recognized by John Zachary Young in 1939. It lies in the stellate ganglion on each side of the midline, at the posterior wall of the squid’s muscular mantle. Activation of this synapse triggers a synchronous contraction of the mantle musculature, causing the forceful ejection of a jet of water from the mantle. This water propulsion allows the squid to move rapidly through the water and even to jump through the surface of the water (breaking the air-water interface) to escape predators. The signal to the mantle is transmitted via a chain consisting of three giant neurons organized in sequence. The first is located in the ventral magnocellular lobe, central to the eyes. It serves as a central integrating manifold that receives all sensory systems and consists of two symmetrical neurons (I). They, in turn, contact secon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Synapse
Chemical synapses are biological junctions through which neurons' signals can be sent to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie perception and thought. They allow the nervous system to connect to and control other systems of the body. At a chemical synapse, one neuron releases neurotransmitter molecules into a small space (the synaptic cleft) that is adjacent to another neuron. The neurotransmitters are contained within small sacs called synaptic vesicles, and are released into the synaptic cleft by exocytosis. These molecules then bind to neurotransmitter receptors on the postsynaptic cell. Finally, the neurotransmitters are cleared from the synapse through one of several potential mechanisms including enzymatic degradation or re-uptake by specific transporters either on the presynaptic cell or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axons
An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit information to different neurons, muscles, and glands. In certain sensory neurons ( pseudounipolar neurons), such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the periphery to the cell body and from the cell body to the spinal cord along another branch of the same axon. Axon dysfunction can be the cause of many inherited and acquired neurological disorders that affect both the peripheral and central neurons. Nerve fibers are classed into three types group A nerve fibers, group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squid Giant Axon
The squid giant axon is the very large (up to 1.5 mm in diameter; typically around 0.5 mm) axon that controls part of the water jet propulsion system in squid. It was first described by L. W. Williams in 1909, but this discovery was forgotten until English zoologist and neurophysiologist J. Z. Young demonstrated the axon's function in the 1930s while working in the Stazione Zoologica in Naples, the Marine Biological Association in Plymouth and the Marine Biological Laboratory in Woods Hole. Squids use this system primarily for making brief but very fast movements through the water. On the underside of the squid's body, between the head and the mantle, is a siphon through which water can be rapidly expelled by the fast contractions of the body wall muscles of the animal. This contraction is initiated by action potentials in the giant axon. Action potentials travel faster in a larger axon than a smaller one, and squid have evolved the giant axon to improve the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RL Squid Synapse 2
RL, Rl or rl may refer to: In arts and entertainment * Radio Liberty, US broadcaster * ''Rocket League'', a video game Businesses and organizations * Polo Ralph Lauren (NYSE stock ticker symbol) * Réseau Luxembourgeois des Amateurs d'Ondes Courtes, an amateur radio organization in Luxembourg * Royal Phnom Penh Airways (IATA code) People known by the given initials * R. L. Huggar, an R&B singer * RL Grime, American musician, producer In science and technology * RL (complexity), a complexity class of mathematical problems * RL circuit, a circuit with a resistor and an inductor * Reinforcement learning, an area of machine learning * Reduced level, elevations of survey points with reference to a common assumed datum. * ''Rhyncholaelia'' (''Rl.''), a genus of orchids Other uses * Rl (digraph) in Australian Aboriginal languages * Acura RL, an automobile * Real life, Internet term * Registered Locksmith, US certification * Report Long, a type of US Congressional Research Service Repo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calyx Of Held
The Calyx of Held is a particularly large synapse in the mammalian auditory central nervous system, so named after Hans Held who first described it in his 1893 article ''Die centrale Gehörleitung''Held, H. "Die centrale Gehörleitung" Arch. Anat. Physiol. Anat. Abt, 1893 because of its resemblance to the calyx of a flower. Globular bushy cells in the anteroventral cochlear nucleus (AVCN) send axons to the contralateral medial nucleus of the trapezoid body (MNTB), where they synapse via these calyces on MNTB principal cells. These principal cells then project to the ipsilateral lateral superior olive (LSO), where they inhibit postsynaptic neurons and provide a basis for interaural level detection (ILD), required for high frequency sound localization. This synapse has been described as the largest in the brain. The related endbulb of Held is also a large axon terminal smaller synapse (15-30 μm in diameter) found in other auditory brainstem structures, namely the cochlear n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equilibrium Potential
In a biological membrane, the reversal potential is the membrane potential at which the direction of ionic current reverses. At the reversal potential, there is no net flow of ions from one side of the membrane to the other. For channels that are permeable to only a single type of ions, the reversal potential is identical to the equilibrium potential of the ion. Equilibrium potential The equilibrium potential for an ion is the membrane potential at which there is no net movement of the ion. The flow of any inorganic ion, such as Na+ or K+, through an ion channel (since membranes are normally impermeable to ions) is driven by the electrochemical gradient for that ion. This gradient consists of two parts, the difference in the concentration of that ion across the membrane, and the voltage gradient. When these two influences balance each other, the electrochemical gradient for the ion is zero and there is no net flow of the ion through the channel; this also translates to no curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin ''calx'' "lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RL Squid 1
RL, Rl or rl may refer to: In arts and entertainment * Radio Liberty, US broadcaster * ''Rocket League'', a video game Businesses and organizations * Polo Ralph Lauren (NYSE stock ticker symbol) * Réseau Luxembourgeois des Amateurs d'Ondes Courtes, an amateur radio organization in Luxembourg * Royal Phnom Penh Airways (IATA code) People known by the given initials * R. L. Huggar, an R&B singer * RL Grime, American musician, producer In science and technology * RL (complexity), a complexity class of mathematical problems * RL circuit, a circuit with a resistor and an inductor * Reinforcement learning, an area of machine learning * Reduced level, elevations of survey points with reference to a common assumed datum. * ''Rhyncholaelia'' (''Rl.''), a genus of orchids Other uses * Rl (digraph) in Australian Aboriginal languages * Acura RL, an automobile * Real life, Internet term * Registered Locksmith, US certification * Report Long, a type of US Congressional Research Service Repo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrew Huxley
Sir Andrew Fielding Huxley (22 November 191730 May 2012) was an English physiologist and biophysicist. He was born into the prominent Huxley family. After leaving Westminster School in central London, he went to Trinity College, Cambridge on a scholarship, after which he joined Alan Lloyd Hodgkin to study nerve impulses. Their eventual discovery of the basis for propagation of nerve impulses (called an action potential) earned them the Nobel Prize in Physiology or Medicine in 1963. They made their discovery from the giant axon of the Atlantic squid. Soon after the outbreak of the Second World War, Huxley was recruited by the British Anti-Aircraft Command and later transferred to the Admiralty. After the war he resumed research at the University of Cambridge, where he developed interference microscopy that would be suitable for studying muscle fibres. In 1952, he was joined by a German physiologist Rolf Niedergerke. Together they discovered in 1954 the mechanism of musc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squid
True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting these criteria. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin. Squid diverged from other cephalopods during the Jurassic and occupy a similar role to teleost fish as open water predators of similar size and behaviour. They play an important role in the open water food web. The two long tentacles are used to grab prey and the eight arms to hold and control it. The beak then cuts the food into suitable size chunks for swallowing. Squid are rapid swimmers, moving by jet propulsion, and largely locate their prey by sight. They are among the most intelligent o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alan Hodgkin
Sir Alan Lloyd Hodgkin (5 February 1914 – 20 December 1998) was an English physiologist and biophysicist who shared the 1963 Nobel Prize in Physiology or Medicine with Andrew Huxley and John Eccles. Early life and education Hodgkin was born in Banbury, Oxfordshire, on 5 February 1914. He was the oldest of three sons of Quakers George Hodgkin and Mary Wilson Hodgkin. His father was the son of Thomas Hodgkin and had read for the Natural Science Tripos at Cambridge where he had befriended electrophysiologist Keith Lucas. Because of poor eyesight he was unable to study medicine and eventually ended up working for a bank in Banbury. As members of the Society of Friends, George and Mary opposed the Military Service Act of 1916 and had to endure a great deal of abuse from their local community, including an attempt to throw George in one of the town canals. In 1916 George Hodgkin travelled to Armenia as part of an investigation of distress. Moved by the misery and suffering of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensory Systems
The sensory nervous system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory neurons (including the sensory receptor cells), neural pathways, and parts of the brain involved in sensory perception. Commonly recognized sensory systems are those for vision, hearing, touch, taste, smell, and balance. Senses are transducers from the physical world to the realm of the mind where people interpret the information, creating their perception of the world around them. The receptive field is the area of the body or environment to which a receptor organ and receptor cells respond. For instance, the part of the world an eye can see, is its receptive field; the light that each rod or cone can see, is its receptive field. Receptive fields have been identified for the visual system, auditory system and somatosensory system. Stimulus :Organisms need information to solve at least three kinds of problems: (a) to maintain an a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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