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Golgi Tendon Organ
The Golgi tendon organ (GTO) (also called Golgi organ, tendon organ, neurotendinous organ or neurotendinous spindle) is a proprioceptor – a type of sensory receptor that senses changes in muscle tension. It lies at the interface between a muscle and its tendon known as the musculotendinous junction also known as the myotendinous junction. It provides the sensory component of the Golgi tendon reflex. The Golgi tendon organ is one of several eponymous terms named after the Italian physician Camillo Golgi. Structure The body of the Golgi tendon organ is made up of braided strands of collagen (intrafusal fasciculi) that are less compact than elsewhere in the tendon and are encapsulated. The capsule is connected in series (along a single path) with a group of muscle fibers () at one end, and merge into the tendon proper at the other. Each capsule is about long, has a diameter of about , and is perforated by one or more afferent type Ib sensory nerve fibers ( Aɑ fiber), whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achilles Tendon
The Achilles tendon or heel cord, also known as the calcaneal tendon, is a tendon at the back of the lower leg, and is the thickest in the human body. It serves to attach the plantaris, gastrocnemius (calf) and soleus muscles to the calcaneus (heel) bone. These muscles, acting via the tendon, cause plantar flexion of the foot at the ankle joint, and (except the soleus) flexion at the knee. Abnormalities of the Achilles tendon include inflammation ( Achilles tendinitis), degeneration, rupture, and becoming embedded with cholesterol deposits ( xanthomas). The Achilles tendon was named in 1693 after the Greek hero Achilles. History The oldest-known written record of the tendon being named after Achilles is in 1693 by the Flemish/Dutch anatomist Philip Verheyen. In his widely used text he described the tendon's location and said that it was commonly called "the cord of Achilles." The tendon has been described as early as the time of Hippocrates, who described it as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axon
An axon (from Greek ἄξων ''áxōn'', axis) or nerve fiber (or nerve fibre: see American and British English spelling differences#-re, -er, spelling differences) is a long, slender cellular extensions, projection of a nerve cell, or neuron, in Vertebrate, vertebrates, that typically conducts electrical impulses known as action potentials away from the Soma (biology), 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 peripheral nervous system, 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 nervous system, peripheral and Central nervous system, central ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Neurophysiology
The ''Journal of Neurophysiology'' is a monthly Peer review, peer-reviewed scientific journal established in 1938. It is published by the American Physiological Society with Jan "Nino" Ramirez as its editor-in-chief. Ramirez is the Director for the Center for Integrative Brain Research at the University of Washington. The ''Journal of Neurophysiology'' publishes original articles on the function of the nervous system. All levels of function are included, from membrane biophysics to cell biology to systems neuroscience and the experimental analysis of behavior. Experimental approaches include molecular neurobiology, cell culture and slice preparations, membrane physiology, developmental neurobiology, functional neuroanatomy, neurochemistry, neuropharmacology, systems electrophysiology, imaging and mapping techniques, and behavioral analysis. Experimental preparations may be invertebrate or vertebrate species, including humans. Theoretical studies are acceptable if they are tied cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interneuron
Interneurons (also called internuncial neurons, association neurons, connector neurons, or intermediate neurons) are neurons that are not specifically motor neurons or sensory neurons. Interneurons are the central nodes of neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS). They play vital roles in reflexes, neuronal oscillations, and neurogenesis in the adult mammalian brain. Interneurons can be further broken down into two groups: local interneurons and relay interneurons. Local interneurons have short axons and form circuits with nearby neurons to analyze small pieces of information. Relay interneurons have long axons and connect circuits of neurons in one region of the brain with those in other regions. However, interneurons are generally considered to operate mainly within local brain areas. The interaction between interneurons allows the brain to perform complex functions such as learning and decision-making. Stru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapse
In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending on the mechanism of signal transmission between neurons. In the case of electrical synapses, neurons are coupled bidirectionally with each other through gap junctions and have a connected cytoplasmic milieu. These types of synapses are known to produce synchronous network activity in the brain, but can also result in complicated, chaotic network level dynamics. Therefore, signal directionality cannot always be defined across electrical synapses. Chemical synapses, on the other hand, communicate through neurotransmitters released from the presynaptic neuron into the synaptic cleft. Upon release, these neurotransmitters bind to specific receptors on the postsynaptic membrane, inducing an electrical or chemical response in the target neuron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stretch Reflex
The stretch reflex (myotatic reflex), or more accurately ''muscle stretch reflex'', is a muscle contraction in response to stretching a muscle. The function of the reflex is generally thought to be maintaining the muscle at a constant length but the response is often coordinated across multiple muscles and even joints. The older term ''deep tendon reflex'' is now criticized as misleading. Tendons have little to do with the response, and some muscles with stretch reflexes have no tendons. Rather, muscle spindles detect a stretch and convey the information to the central nervous system. As an example of a spinal reflex, it results in a fast response that involves an afferent signal into the spinal cord and an efferent signal out to the muscle. The stretch reflex can be a monosynaptic reflex which provides automatic regulation of skeletal muscle length, whereby the signal entering the spinal cord arises from a change in muscle length or velocity. It can also include a polysynaptic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feedback
Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause and effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled carefully when applied to feedback systems: History Self-regulating mechanisms have existed since antiquity, and the idea of feedback started to enter economic theory in Britain by the 18th century, but it was not at that time recognized as a universal abstraction and so did not have a name. The first ever known artificial feedback device was a float valve, for maintaining water at a constant level, invented in 270 BC in Alexandria, Egypt. This device illustrated the principle of feedback: a low water level opens the valve, the rising water then provides feedback into the system, closing the valve when the required level is reached. This then reoccurs in a circular fashion as the water level fluctuates. Centrifugal governors were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Physiology
''The Journal of Physiology'' is a semi-monthly peer-reviewed scientific journal that was established in 1878 and is published by Wiley-Blackwell on behalf of The Physiological Society. It covers research on all aspects of physiology, with an emphasis on human and mammalian physiology, including work at the molecular level, at the level of the cell membrane, single cells, tissues or organs, and systems physiology. The full archive back to 1878 up to issues published 12 months from the current date is freely available online. The editor-in-chief is Kim Barrett (University of California, Davis). According to the ''Journal Citation Reports'', the journal has a 2022 impact factor of 5.5. History The journal was first published in 1878 and edited by Michael Foster. In 1893–1894 Foster's colleague John Newport Langley took over as editor. Langley remained the proprietor and editor until his death in 1925, when The Physiological Society bought the journal from his widow. Charles S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Force
In physics, a force is an influence that can cause an Physical object, object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the Magnitude (mathematics), magnitude and Direction (geometry, geography), direction of a force are both important, force is a Euclidean vector, vector quantity. The SI unit of force is the newton (unit), newton (N), and force is often represented by the symbol . Force plays an important role in classical mechanics. The concept of force is central to all three of Newton's laws of motion. Types of forces often encountered in classical mechanics include Elasticity (physics), elastic, frictional, Normal force, contact or "normal" forces, and gravity, gravitational. The rotational version of force is torque, which produces angular acceleration, changes in the rotational speed of an object. In an extended body, each part applies forces on the adjacent pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal cord is hollow and contains a structure called the central canal, which contains cerebrospinal fluid. The spinal cord is also covered by meninges and enclosed by the neural arches. Together, the brain and spinal cord make up the central nervous system. In humans, the spinal cord is a continuation of the brainstem and anatomically begins at the occipital bone, passing out of the foramen magnum and then enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae, where it tapers to become the cauda equina. The enclosing bony vertebral column protects the relatively shorter spinal cord. It is around long in adult men and around long in adult women. The diam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Action Potential
An action potential (also known as a nerve impulse or "spike" when in a neuron) is a series of quick changes in voltage across a cell membrane. An action potential occurs when the membrane potential of a specific Cell (biology), cell rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of Membrane potential#Cell excitability, excitable cells, which include animal cells like neurons and myocyte, muscle cells, as well as some plant cells. Certain endocrine cells such as pancreatic beta cells, and certain cells of the anterior pituitary gland are also excitable cells. In neurons, action potentials play a central role in cell–cell interaction, cell–cell communication by providing for—or with regard to saltatory conduction, assisting—the propagation of signals along the neuron's axon toward axon terminal, synaptic boutons situated at the ends of an axon; these signals can then connect wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cation
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons (e.g. K+ ( potassium ion)) while an anion is a negatively charged ion with more electrons than protons (e.g. Cl− ( chloride ion) and OH− ( hydroxide ion)). Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed ''monatomic ions'', ''atomic ions'' or ''simple ions'', while ions consisting of two or more atoms are termed polyatomic ions or ''molecular ions''. If only a + or − is present, it indic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
