Aftereffect
Neural adaptation or sensory adaptation is a gradual decrease over time in the responsiveness of the sensory system to a constant stimulus. It is usually experienced as a change in the stimulus. For example, if a hand is rested on a table, the table's surface is immediately felt against the skin. Subsequently, however, the sensation of the table surface against the skin gradually diminishes until it is virtually unnoticeable. The sensory neurons that initially respond are no longer stimulated to respond; this is an example of neural adaptation. All sensory and neural systems have a form of adaptation to constantly detect changes in the environment. Neural receptor cells that process and receive stimulation go through constant changes for mammals and other living organisms to sense vital changes in their environment. Some key players in several neural systems include Ca2+ions (see Calcium in biology) that send negative feedback in second messenger pathways that allow the neural rece ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Sensory System
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 and interoception. Commonly recognized sensory systems are those for vision, hearing, touch, taste, smell, balance and visceral sensation. Sense organs are transducers that convert data from the outer 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. Senses and receptors Whi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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PsycNET
PsycINFO is a database of abstracts of literature in the field of psychology. It is produced by the American Psychological Association and distributed on the association's APA PsycNET and through third-party vendors. It is the electronic version of the now-ceased ''Psychological Abstracts''. In 2000, it absorbed PsycLIT which had been published on CD-ROM. PsycINFO contains citations and summaries from the 19th century to the present of journal articles, book chapters, books, and dissertations. Overview The database, which is updated weekly, contained over 3.5 million records as of October 2013. Approximately 175,000 records were added to the database in 2012. Coverage More than 2,540 peer-reviewed journal titles are included in the database, and they make up 78% of the overall content. Journals are included if they are archival, scholarly, peer-reviewed, and regularly published with titles, abstracts, and keywords in English. As of October 2013, over 1,700 journal titles ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Habituation
Habituation is a form of non-associative learning in which an organism’s non-reinforced response to an inconsequential stimulus decreases after repeated or prolonged presentations of that stimulus. For example, organisms may habituate to repeated sudden loud noises when they learn that these have no consequences. Habituation can occur in responses that habituate include those that involve an entire organism or specific biological component systems of an organism. The broad ubiquity of habituation across all forms of life has led to it being called "the simplest, most universal form of learning...as fundamental a characteristic of life as DNA." Functionally, habituation is thought to free up cognitive resources for other stimuli that are associated with biologically important events by diminishing the response to inconsequential stimuli. A progressive decline of a behavior in a habituation procedure may also reflect nonspecific effects such as fatigue, which must be ruled ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Motor Cortex
The motor cortex is the region of the cerebral cortex involved in the planning, motor control, control, and execution of voluntary movements. The motor cortex is an area of the frontal lobe located in the posterior precentral gyrus immediately anterior to the central sulcus. Components The motor cortex can be divided into three areas: 1. The primary motor cortex is the main contributor to generating neural impulses that pass down to the spinal cord and control the execution of movement. However, some of the other motor areas in the brain also play a role in this function. It is located on the anterior paracentral lobule on the medial surface. 2. The premotor cortex is responsible for some aspects of motor control, possibly including the preparation for movement, the sensory guidance of movement, the spatial guidance of reaching, or the direct control of some movements with an emphasis on control of proximal and trunk muscles of the body. Located anterior to the primary mo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Alpha Motor Neuron
Alpha (α) motor neurons (also called alpha motoneurons), are large, multipolar neuron, multipolar lower motor neurons of the brainstem and spinal cord. They innervate extrafusal muscle fibers of skeletal muscle and are directly responsible for initiating their muscle contraction, contraction. Alpha motor neurons are distinct from gamma motor neurons, which innervate intrafusal muscle fibers of muscle spindles. While their cell body, cell bodies are found in the central nervous system (CNS), α motor neurons are also considered part of the somatic nervous system—a branch of the peripheral nervous system (PNS)—because their axons extend into the periphery to innervate skeletal muscles. An alpha motor neuron and the muscle fibers it innervates comprise a motor unit. A motor neuron pool contains the cell bodies of all the alpha motor neurons involved in contracting a single muscle. Location Alpha motor neurons (α-MNs) innervating the head and neck are found in the brainstem; t ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Hoffmann's Reflex
Hoffmann's reflex (Hoffmann's sign, sometimes simply Hoffmann's, or finger flexor reflex) is a neurological examination finding elicited by a reflex test which can help verify the presence or absence of issues arising from the corticospinal tract. It is named after neurologist Johann Hoffmann (neurologist), Johann Hoffmann. Usually considered a pathological reflex in a clinical setting, the Hoffmann's reflex has also been used as a measure of spinal reflex processing (adaptation) in response to Physical exercise, exercise training. Procedure The Hoffmann's reflex test itself involves loosely holding the middle finger and flicking the fingernail downward, allowing the middle finger to flick upward reflexively. A positive response is seen when there is flexion and adduction of the thumb on the same hand. Hoffma ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Motor Unit Recruitment
Motor unit recruitment is the activation of additional motor units to accomplish an increase in contractile strength in a muscle. A motor unit consists of one motor neuron and all of the muscle fibers it stimulates. All muscles consist of a number of motor units and the fibers belonging to a motor unit are dispersed and intermingle amongst fibers of other units. The muscle fibers belonging to one motor unit can be spread throughout part, or most of the entire muscle, depending on the number of fibers and size of the muscle. When a motor neuron is activated, all of the muscle fibers innervated by the motor neuron are stimulated and contract. The activation of one motor neuron will result in a weak but distributed muscle contraction. The activation of more motor neurons will result in more muscle fibers being activated, and therefore a stronger muscle contraction. Motor unit recruitment is a measure of how many motor neurons are activated in a particular muscle, and therefore is a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Motor Unit
In biology, a motor unit is made up of a motor neuron and all of the skeletal muscle fibers innervated by the neuron's axon terminals, including the neuromuscular junctions between the neuron and the fibres. Groups of motor units often work together as a motor pool to coordinate the contractions of a single muscle. The concept was proposed by Charles Scott Sherrington. Usually muscle fibers in a motor unit are of the same fiber type. When a motor unit is activated, all of its fibers contract. In vertebrates, the force of a muscle contraction is controlled by the number of activated motor units. The number of muscle fibers within each unit can vary within a particular muscle and even more from muscle to muscle: the muscles that act on the largest body masses have motor units that contain more muscle fibers, whereas smaller muscles contain fewer muscle fibers in each motor unit. For instance, thigh muscles can have a thousand fibers in each unit, while extraocular muscles mi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Anatomical Terms Of Muscle
Anatomical terminology is used to uniquely describe aspects of skeletal muscle, cardiac muscle, and smooth muscle such as their actions, structure, size, and location. Types There are three types of muscle tissue in the body: skeletal, smooth, and cardiac. Skeletal muscle Skeletal muscle, or "voluntary muscle", is a striated muscle tissue that primarily joins to bone with tendons. Skeletal muscle enables movement of bones, and maintains posture. The widest part of a muscle that pulls on the tendons is known as the belly. Muscle slip A muscle slip is a slip of muscle that can either be an anatomical variant, or a branching of a muscle as in rib connections of the serratus anterior muscle. Smooth muscle Smooth muscle is involuntary and found in parts of the body where it conveys action without conscious intent. The majority of this type of muscle tissue is found in the digestive and urinary systems where it acts by propelling forward food, chyme, and feces in the former and u ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Electromyography
Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG is performed using an instrument called an electromyograph to produce a record called an electromyogram. An electromyograph detects the electric potential generated by muscle cells when these cells are electrically or neurologically activated. The signals can be analyzed to detect abnormalities, activation level, or recruitment order, or to analyze the biomechanics of human or animal movement. Needle EMG is an electrodiagnostic medicine technique commonly used by neurologists. Surface EMG is a non-medical procedure used to assess muscle activation by several professionals, including physiotherapists, kinesiologists and biomedical engineers. In computer science, EMG is also used as middleware in gesture recognition towards allowing the input of physical action to a computer as a form of human-computer interaction. Clinical uses EMG testing has a varie ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Education Portal
Education is the transmission of knowledge and skills and the development of character traits. Formal education occurs within a structured institutional framework, such as public schools, following a curriculum. Non-formal education also follows a structured approach but occurs outside the formal schooling system, while informal education involves unstructured learning through daily experiences. Formal and non-formal education are categorized into levels, including early childhood education, primary education, secondary education, and tertiary education. Other classifications focus on teaching methods, such as teacher-centered and Student-centered learning, student-centered education, and on subjects, such as science education, language education, and physical education. Additionally, the term "education" can denote the mental states and qualities of educated individuals and the academic field studying educational phenomena. The precise definition of education is disputed, an ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Calmodulin
Calmodulin (CaM) (an abbreviation for calcium-modulated protein) is a multifunctional intermediate calcium-binding messenger protein expressed in all Eukaryote, eukaryotic cells. It is an intracellular target of the Second messenger system, secondary messenger Calcium in biology, Ca2+, and the binding of Ca2+ is required for the activation of calmodulin. Once bound to Ca2+, calmodulin acts as part of a calcium Signal transduction, signal transduction pathway by modifying its interactions with various target proteins such as kinases or phosphatases. Structure Calmodulin is a small, highly conserved protein that is 148 amino acids long (16.7 kDa). The protein has two approximately symmetrical globular domains (the N- and C- domains) each containing a pair of EF hand Sequence motif, motifs separated by a flexible linker region for a total of four Ca2+ binding sites, two in each globular domain. In the Ca2+-free state, the helices that form the four EF-hands are collapsed in a co ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |