|
Reciprocal Innervation
René Descartes (1596–1650) was one of the first to conceive a model of reciprocal innervation (in 1626) as the principle that provides for the control of agonist and antagonist muscles. Reciprocal innervation describes skeletal muscles as existing in antagonistic pairs, with contraction of one muscle producing forces opposite to those generated by contraction of the other. For example, in the human arm, the triceps acts to extend the lower arm outward while the biceps acts to flex the lower arm inward. To reach optimum efficiency, contraction of opposing muscles must be inhibited while muscles with the desired action are excited. This reciprocal innervation occurs so that the contraction of a muscle results in the simultaneous relaxation of its corresponding antagonist. A common example of reciprocal innervation, is the effect of the nociceptive (or nocifensive) reflex, or defensive response to pain, otherwise commonly known as the withdrawal reflex The withdrawal r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
René Descartes
René Descartes ( , ; ; 31 March 1596 – 11 February 1650) was a French philosopher, scientist, and mathematician, widely considered a seminal figure in the emergence of modern philosophy and Modern science, science. Mathematics was paramount to his method of inquiry, and he connected the previously separate fields of geometry and algebra into analytic geometry. Descartes spent much of his working life in the Dutch Republic, initially serving the Dutch States Army, and later becoming a central intellectual of the Dutch Golden Age. Although he served a Dutch Reformed Church, Protestant state and was later counted as a Deism, deist by critics, Descartes was Roman Catholicism, Roman Catholic. Many elements of Descartes's philosophy have precedents in late Aristotelianism, the Neostoicism, revived Stoicism of the 16th century, or in earlier philosophers like Augustine of Hippo, Augustine. In his natural philosophy, he differed from the Scholasticism, schools on two major point ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Scott Sherrington
Sir Charles Scott Sherrington (27 November 1857 – 4 March 1952) was a British neurophysiology, neurophysiologist. His experimental research established many aspects of contemporary neuroscience, including the concept of the spinal reflex as a system involving connected neurons (the "neuron doctrine"), and the ways in which signal transmission between neurons can be potentiated or depotentiated. Sherrington himself coined the word "synapse" to define the connection between two neurons. His book ''The Integrative Action of the Nervous System'' (1906) is a synthesis of this work, in recognition of which he was awarded the Nobel Prize in Physiology or Medicine in 1932 (along with Edgar Adrian). In addition to his work in physiology, Sherrington did research in histology, bacteriology, and pathology. He was president of the Royal Society in the early 1920s. Biography Early years and education Official biographies claim Charles Scott Sherrington was born in Islington, London, Engl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscular System
The muscular system is an organ (anatomy), organ system consisting of skeletal muscle, skeletal, smooth muscle, smooth, and cardiac muscle, cardiac muscle. It permits movement of the body, maintains posture, and circulates blood throughout the body. The muscular systems in vertebrates are controlled through the nervous system although some muscles (such as the cardiac muscle) can be completely autonomous. Together with the Human skeleton, skeletal system in the human, it forms the musculoskeletal system, which is responsible for the movement of the human body, body. Types There are three distinct types of muscle: skeletal muscle, cardiac muscle, cardiac or heart muscle, and smooth muscle, smooth (non-striated) muscle. Muscles provide strength, balance, posture, movement, and heat for the body to keep warm. There are more than 600 muscles in an adult male human body. A kind of elastic tissue makes up each muscle, which consists of thousands, or tens of thousands, of small musc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthoptics
Orthoptics is a profession allied to the eye care profession. Orthoptists are the experts in diagnosing and treating defects in eye movements and problems with how the eyes work together, called binocular vision. These can be caused by issues with the muscles around the eyes or defects in the nerves enabling the brain to communicate with the eyes. Orthoptists are responsible for the diagnosis and non-surgical management of strabismus (cross-eyed), amblyopia (lazy eye) and eye movement disorders.International Orthoptic Association document "professional role" The word ''orthoptics'' comes from the Ancient Greek, Greek words ὀρθός ''orthos'', "straight" and ὀπτικός ''optikοs'', "relating to sight" and much of the practice of orthoptists concerns disorders of binocular vision and defects of eye movement. Orthoptists are trained professionals who specialize in orthoptic treatment, such as eye patches, eye exercises, prisms or glasses. They commonly work with paediatric pat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissociated Vertical Deviation
Dissociated vertical deviation (DVD) is an eye condition which occurs in association with a squint, typically infantile esotropia. The exact cause is unknown, although it is logical to assume it is from faulty innervation of eye muscles. Presentation The eye drifts upward spontaneously or after being covered. The condition usually affects both eyes, but can occur unilaterally or asymmetrically. It is often associated with latent or manifest-latent nystagmus and, as well as occurring with infantile esotropia, can also be found associated with exotropias and vertical deviations. DVDs are usually controlled from occurring with both eyes open, but may become manifest with inattention. Usually some level of dissociative occlusion is required to trigger the brain to suppress vision in that eye and then not control a DVD from occurring. The level of dissociative occlusion required may involve using a red filter, a darker filter or complete occlusion (e.g. with a hand). Onset DVD typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hering's Law Of Equal Innervation
Hering's law of equal innervation is used to explain the conjugacy of saccadic eye movement in stereoptic animals. The law proposes that conjugacy of saccades is due to innate connections in which the eye muscles responsible for each eye's movements are innervated equally. The law also states that apparent monocular eye movements are actually the summation of conjugate version and disjunctive (or vergence) eye movements. The law was put forward by Ewald Hering in the 19th century, though the underlying principles of the law date back considerably. Aristotle had commented upon this phenomenon and Ptolemy put forward a theory of why such a physiological law might be useful. The 11th century scholar Ibn al-Haytham stated that eyes move together and equally so that the visual axes converge on an object of interest in his ''Book of Optics''. Hering's law of equal innervation is best understood with Johannes Peter Müller's stimulus where an observer refoveates a point that moved i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reciprocal Inhibition
Reciprocal inhibition is a neuromuscular process in which muscles on one side of a joint relax to allow the contraction of muscles on the opposite side, enabling smooth and coordinated movement. This concept, introduced by Charles Sherrington, a pioneering neuroscientist, is also referred to as ''reflexive antagonism'' in some allied health fields. Sherrington, one of the founding figures in neurophysiology, observed that when the central nervous system signals an agonist muscle to contract, inhibitory signals are sent to the antagonist muscle, encouraging it to relax and reduce resistance. This mechanism, known as reciprocal inhibition, is essential for efficient movement and helps prevent muscle strain by balancing forces around a joint. Mechanics Joints are controlled by two opposing sets of muscles called extensors and flexors, that work in synchrony for smooth movement. When a muscle spindle is stretched, the stretch reflex is activated, and the opposing muscle group mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioengineering
Biological engineering or bioengineering is the application of principles of biology and the tools of engineering to create usable, tangible, economically viable products. Biological engineering employs knowledge and expertise from a number of pure and applied sciences, such as mass transfer, mass and heat transfer, Kinetics (physics), kinetics, biocatalysts, biomechanics, bioinformatics, separation process, separation and List of purification methods in chemistry, purification processes, bioreactor design, surface science, fluid mechanics, thermodynamics, and polymer science. It is used in the design of medical devices, diagnostic equipment, biocompatible materials, renewable energy, ecological engineering, agricultural engineering, process engineering and catalysis, and other areas that improve the living standards of societies. Examples of bioengineering research include bacteria engineered to produce chemicals, new medical imaging technology, portable and rapid diagnosti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extraocular Muscle
The extraocular muscles, or extrinsic ocular muscles, are the seven extrinsic muscles of the eye in humans and other animals. Six of the extraocular muscles, the four recti muscles, and the superior and inferior oblique muscles, control movement of the eye. The other muscle, the levator palpebrae superioris, controls eyelid elevation. The actions of the six muscles responsible for eye movement depend on the position of the eye at the time of muscle contraction. The ciliary muscle, pupillary sphincter muscle and pupillary dilator muscle sometimes are called intrinsic ocular muscles or intraocular muscles. Structure Since only a small part of the eye called the fovea provides sharp vision, the eye must move to follow a target. Eye movements must be precise and fast. This is seen in scenarios like reading, where the reader must shift gaze constantly. Although under voluntary control, most eye movement is accomplished without conscious effort. Precisely how the integration betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Eye
The human eye is a sensory organ in the visual system that reacts to light, visible light allowing eyesight. Other functions include maintaining the circadian rhythm, and Balance (ability), keeping balance. The eye can be considered as a living optics, optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially stray light, light tight except on the eye's optic axis. In order, along the optic axis, the optical components consist of a first lens (the cornea, cornea—the clear part of the eye) that accounts for most of the optical power of the eye and accomplishes most of the Focus (optics), focusing of light from the outside world; then an aperture (the pupil) in a Diaphragm (optics), diaphragm (the Iris (anatomy), iris—the coloured part of the eye) that controls the amount of light entering the interior of the eye; then an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonist (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 Proprioception#Reflexes, 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 system, digestive and urinary systems where it acts by propelling forward foo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Withdrawal Reflex
The withdrawal reflex (nociceptive flexion reflex or flexor withdrawal reflex) is a spinal reflex intended to protect the body from damaging stimuli. The reflex rapidly coordinates the contractions of all the flexor muscles and the relaxations of the extensors in that limb causing sudden withdrawal from the potentially damaging stimulus. Spinal reflexes are often monosynaptic and are mediated by a simple reflex arc. A withdrawal reflex is mediated by a reflex arc, polysynaptic reflex resulting in the stimulation of many motor neurons in order to give a quick response. Example When a person touches a hot object and withdraws their hand from it without actively thinking about it, the heat stimulates Thermoreceptor, temperature and Nociceptor, pain receptors in the skin, triggering a sensory impulse that travels to the central nervous system. The sensory neuron then synapses with spinal interneuron, interneurons that connect to motor neurons. Some of these send motor impulses to the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
