• It encompasses the sensing of depolarisation of the plasma membrane coupled with the release of Ca2+ from intracellular stores. (ucc.ie)
  • The cell or plasma membrane that encloses each muscle fiber. (perch.fit)
  • T (transverse) tubules penetrate from the surface plasma membrane, the sarcolemma, to the interior of the cell, allowing the electrical impulse to reach the interior. (lumenlearning.com)
  • In the cells that perform exhibit viral proteins, these proteins are internalised upon antibody addition through an extremely effective and fast procedure leading to FIPV-infected cells without aesthetically detectable viral proteins on the plasma membrane [3]. (conferencedequebec.org)
  • Block of Cx43 hemichannels or a reduction in Cx43 levels (using Dmd mdx Cx43 +/- mice) prevents the abnormal increase in membrane permeability, plasma membrane depolarization, and Iso-evoked electrical activity in these cells. (jci.org)
  • The sarcoplasmic reticulum (SR) is a membrane-bound structure found within muscle cells that is similar to the smooth endoplasmic reticulum in other cells. (wikipedia.org)
  • The sarcoplasmic reticulum is a network of tubules that extend throughout muscle cells, wrapping around (but not in direct contact with) the myofibrils (contractile units of the cell). (wikipedia.org)
  • The cytosolic side of the pump then closes and the sarcoplasmic reticulum side opens, releasing the Ca2+ into the SR. A protein found in cardiac muscle, called phospholamban (PLB) has been shown to prevent SERCA from working. (wikipedia.org)
  • Small Ankyrins (sAnk1) are muscle-specific isoforms generated by the Ank1 gene that participate in the organization of the sarcoplasmic reticulum (SR) of striated muscles. (mdpi.com)
  • The aim of this work was to characterise possible novel interactions with a proline-rich region of the RyR1, to characterise a monoclonal antibody (mAb VF1c) raised against a junctional sarcoplasmic reticulum protein postulated to interact with RyR1, and to characterise the protein recognised by this antibody in models of skeletal muscle disease such as Duchenne Muscular dystrophy (DMD) and sarcopenia. (ucc.ie)
  • Exercise promotes the formation of intracellular junctions in skeletal muscle between stacks of sarcoplasmic reticulum (SR) cisternae and extensions of transverse-tubules (TT) that increase co-localization of proteins required for store-operated Ca 2+ entry (SOCE). (elifesciences.org)
  • This influx of calcium causes calcium-induced calcium release from the sarcoplasmic reticulum , and free Ca 2+ causes muscle contraction . (wikipedia.org)
  • There are three types of ryanodine receptor, RyR1 (in skeletal muscle), RyR2 (in cardiac muscle) and RyR3 (in the brain). (wikipedia.org)
  • Cardiac muscle has some similarities to neurons and skeletal muscle, as well as important unique properties. (wikipedia.org)
  • Myosin-binding protein C stabilizes, but is not the sole determinant of SRX myosin in cardiac muscle. (tamu.edu)
  • 2017. Ryanodine receptors are part of the myospryn complex in cardiac muscle . (cardiff.ac.uk)
  • Recall that cardiac muscle shares a few characteristics with both skeletal muscle and smooth muscle, but it has some unique properties of its own. (lumenlearning.com)
  • Even though cardiac muscle has autorhythmicity, heart rate is modulated by the endocrine and nervous systems. (lumenlearning.com)
  • There are two major types of cardiac muscle cells: myocardial contractile cells and myocardial conducting cells. (lumenlearning.com)
  • Compared to the giant cylinders of skeletal muscle, cardiac muscle cells, or cardiomyocytes, are considerably shorter with much smaller diameters. (lumenlearning.com)
  • Cardiac muscle also demonstrates striations, the alternating pattern of dark A bands and light I bands attributed to the precise arrangement of the myofilaments and fibrils that are organized in sarcomeres along the length of the cell. (lumenlearning.com)
  • Therefore, there are one-half as many T tubules in cardiac muscle as in skeletal muscle. (lumenlearning.com)
  • Cardiac muscle cells branch freely. (lumenlearning.com)
  • a) Cardiac muscle cells have myofibrils composed of myofilaments arranged in sarcomeres, T tubules to transmit the impulse from the sarcolemma to the interior of the cell, numerous mitochondria for energy, and intercalated discs that are found at the junction of different cardiac muscle cells. (lumenlearning.com)
  • b) A photomicrograph of cardiac muscle cells shows the nuclei and intercalated discs. (lumenlearning.com)
  • c) An intercalated disc connects cardiac muscle cells and consists of desmosomes and gap junctions. (lumenlearning.com)
  • Cardiac muscle undergoes aerobic respiration patterns, primarily metabolizing lipids and carbohydrates. (lumenlearning.com)
  • Cardiac muscle cells undergo twitch-type contractions with long refractory periods followed by brief relaxation periods. (lumenlearning.com)
  • Cardiac and skeletal muscle cells contain structures called transverse tubules (T-tubules), which are extensions of the cell membrane that travel into the centre of the cell. (wikipedia.org)
  • A modified Sihler's procedure was completed on 15 quadratus lumborum muscles to visualize the intramuscular arborization areas in terms of the inferior border of the 12th rib, the transverse processes of L1-L4, and the iliac crest. (researchsquare.com)
  • Immunological studies of the surface membrane from skeletal muscle transverse T-tubules. (anid.cl)
  • Calcium ion release from the SR, occurs in the junctional SR/terminal cisternae through a ryanodine receptor (RyR) and is known as a calcium spark. (wikipedia.org)
  • Accordingly, the volume of SR tubules localized around the myofibrils is strongly reduced in skeletal muscle fibers of 4- and 10-month-old sAnk1 knockout (KO) mice, while additional structural alterations only develop with aging. (mdpi.com)
  • To verify whether the lack of sAnk1 also alters intracellular Ca 2+ handling, cytosolic Ca 2+ levels were analyzed in stimulated skeletal muscle fibers from 4- and 10-month-old sAnk1 KO mice. (mdpi.com)
  • The Purkinje fibers transmit the signals more rapidly to stimulate contraction of the ventricles. (wikipedia.org)
  • An electrochemical signal is sent through the nervous system to a motor neuron that innervates multiple muscle fibers. (perch.fit)
  • Consisting of interlocked fibers (actin and myosin) and is responsible for the striations of muscle fibers. (perch.fit)
  • Bundles of muscle fibers surrounded by the perimysium. (perch.fit)
  • The medium piece of connective tissue that encases multiple muscle fibers in their fascicle structure. (perch.fit)
  • Muscle fibers can broadly be divided into 3 muscles types: skeletal, cardiac, and smooth muscle. (medscape.com)
  • Likewise, the number of muscle fibers within each of these, as well as the shape of muscles (depending on their function), can also vary greatly. (medscape.com)
  • What remains constant, however, is that the muscle fibers are aligned in the same direction so that individual muscle fibers can work in concert. (medscape.com)
  • When the muscles fibers and the associated tendon are arranged along the same axis, the muscle is termed a parallel muscle. (medscape.com)
  • Bipennate muscles have muscles fibers inserting at an angle on both sides of a central tendon. (medscape.com)
  • Each muscle fascicle represents a group of muscle fibers bound together by a layer of connective tissue termed the perimysium. (medscape.com)
  • Only 60% of the axons in the nerve to a given muscle are motor to the muscle fibers that make up the bulk of the muscle. (medscape.com)
  • The nerve supply branches within the muscle belly, forming a plexus from which groups of axons emerge to supply the muscle fibers. (medscape.com)
  • The axons supply single motor endplates placed about halfway along the muscle fibers. (medscape.com)
  • A motor unit comprises a motor neuron in the spinal cord or brainstem together with the squad of muscle fibers it innervates. (medscape.com)
  • In large muscles (eg, the flexors of the hip or knee), each motor unit contains 1200 or more muscle fibers. (medscape.com)
  • In small muscles (eg, the intrinsic muscles of the hand), each unit contains 12 or fewer muscle fibers. (medscape.com)
  • Muscle fibers are long and cylindrical in shape. (medscape.com)
  • RACK1 was expressed transiently in the skeletal muscle of post-natal mice, being abundant in the early phase of muscle growth and almost disappearing in adult mature fibers. (sdbonline.org)
  • After acute injury in muscle of both mouse and the fruit fly Drosophila melanogaster (used as alternative in vivo model) this study found that RACK1 accumulated in regenerating fibers while it declined with the progression of repair process. (sdbonline.org)
  • As such, the structural and functional features of muscle sympathetic innervation are largely undetermined in both physiology and pathology, mainly due to methodological limitations in the histopathological analysis of small neuronal fibers in tissue samples. (bvsalud.org)
  • Forces produced by the contraction of stress fibers not only helps the cell body to translocate during migration [6] [7] , but they also serve as a vital "inside-out? (mechanobio.info)
  • The NM junction or motor end plate consists of a presynaptic membrane of the axonal terminal of the motor neuron, the synaptic space, and the postsynaptic membrane and junctional sarcoplasm of the myofiber. (veteriankey.com)
  • The neurotransmitter released at the NM junction is acetylcholine (ACh), which binds to nicotinic receptors in the postsynaptic membrane and generates an end-plate potential. (veteriankey.com)
  • Myopathies will not be discussed in this chapter except for those resulting from abnormal postsynaptic membrane conduction. (veteriankey.com)
  • Normal neuromuscular junction showing a presynaptic terminal with a motor nerve ending in an enlargement (bouton terminale): Synaptic cleft and postsynaptic membrane with multiple folds and embedded with several acetylcholine receptors. (medscape.com)
  • The smallest piece of connective tissue that encases a singular muscle fiber. (perch.fit)
  • The largest piece of connective tissue, elastic and fibrous sheath that encases the entire muscle, simultaneously allowing it to maintain its integrity and move independently of other tissues and organs nearby. (perch.fit)
  • the layer of thick connective tissue that covers an entire muscle and resides over the layer of epimysium. (perch.fit)
  • Gross inspection of a skeletal muscle reveals collections of muscle fascicles surrounded by a layer connective tissue termed the epimysium. (medscape.com)
  • specialized invaginations of the surface membrane that propagate action potentials to trigger SR Ca 2+ release during excitation-contraction (EC) coupling. (elifesciences.org)
  • This post will help explain the mechanisms of muscular contractions from an anatomical perspective, and how the principles and purposes of velocity based training directly relates. (perch.fit)
  • Providing a number assigned to effort can help athletes understand what muscular contraction feels like at various effort levels and encourage them to be more in tune with their bodies. (perch.fit)
  • Every skeletal muscular contraction (with the exception of reflexes) originates in the brain. (perch.fit)
  • This summary discusses the basic anatomy of skeletal muscle, key features of skeletal muscle histology and physiology, and important presentations of muscular disease. (medscape.com)
  • Most of the skeletal muscular system is arranged into groups of agonists and antagonist muscles that work in concert to provide efficient and controlled motion. (medscape.com)
  • neurodevelopmental syndromes and muscular dystrophies) that affect the brain and striated muscle. (cardiff.ac.uk)
  • Each muscle fiber (myofiber or myocyte) is innervated by a single α-motor neuron, but a single motor neuron may innervate from a few to thousands of myofibers, depending on the function of a given muscle. (veteriankey.com)
  • In muscles such as those of the eye, which are responsible for fine movements, one motor neuron supplies only a few myofibers. (veteriankey.com)
  • In contrast, in muscles involved in posture and locomotion, hundreds to thousands of myofibers are innervated by a single motor neuron. (veteriankey.com)
  • All motor neurons innervating skeletal muscle are excitatory, and a single discharge of a motor neuron results in contraction of all the myofibers that it innervates. (veteriankey.com)
  • The optimized "Neuro Detection Protocol" (NDP) was validated in human muscle biopsies, demonstrating that SNs innervate, at high density, both blood vessels and skeletal myofibers, independent of the fiber metabolic type. (bvsalud.org)
  • As a result of this excessive intracellular calcium, enhanced cardiac contractions, which are delayed after depolarizations, occur. (medscape.com)
  • Except for Purkinje cells, they are generally much smaller than the contractile cells and have few of the myofibrils or filaments needed for contraction. (lumenlearning.com)
  • The longitudinal SR are thinner projects, that run between the terminal cisternae/junctional SR, and are the location where ion channels necessary for calcium ion absorption are most abundant. (wikipedia.org)
  • The SR contains ion channel pumps, within its membrane that are responsible for pumping Ca2+ into the SR. As the calcium ion concentration within the SR is higher than in the rest of the cell, the calcium ions won't freely flow into the SR, and therefore pumps are required, that use energy, which they gain from a molecule called adenosine triphosphate (ATP). (wikipedia.org)
  • It does this by binding to the SERCA and decreasing its attraction (affinity) to calcium, therefore preventing calcium uptake into the SR. Failure to remove Ca2+ from the cytosol, prevents muscle relaxation and therefore means that there is a decrease in muscle contraction too. (wikipedia.org)
  • It is primarily located within the junctional SR/luminal space, in close association with the calcium release channel (described below). (wikipedia.org)
  • Calcium release through ryanodine receptors in the SR is triggered differently in different muscles. (wikipedia.org)
  • Inhibition of AChE resulted in dose-dependent influx of calcium at the junctional region with the consequent development of morphological and biochemical alterations. (aston.ac.uk)
  • Like skeletal muscle, depolarization causes the opening of voltage-gated calcium channels and release of Ca 2+ from the t-tubules . (wikipedia.org)
  • 2019) Correcting the R165K substitution in the first voltage-sensor of Ca V 1.1 right-shifts the voltage-dependence of skeletal muscle calcium channel activation. (i-med.ac.at)
  • Flucher BE, Campiglio M. (2019) STAC proteins: The missing link in skeletal muscle EC coupling and new regulators of calcium channel function. (i-med.ac.at)
  • Flucher, B.E. and Tuluc, P. (2017) How and why are calcium currents curtailed in the skeletal muscle voltage-gated calcium channels? (i-med.ac.at)
  • During Drosophila gastrulation, actomyosin contraction in ventral cells generates a long, narrow epithelial furrow, termed the ventral furrow, in which actomyosin fibres and tension are directed along the length of the furrow. (nature.com)
  • GSOs also mitigated the deleterious effects of GLU on the mitochondrial membrane potential and Cyt C release, thus alleviating mitochondrial dysfunction, and increased GSH levels and CAT activity in both cells and Drosophila brain tissue. (sdbonline.org)
  • In Drosophila with depleted RACK1 in all muscle cells or, specifically, in SC lineage resulted in a delayed recovery of skeletal muscle after physical damage as well as the low presence of active SC in the wound area. (sdbonline.org)
  • The pathophysiology that produces cardiotoxicity involves prolonging refractory period in atrioventricular (AV) node, shortening refractory periods in atria and ventricles, and decreasing resting membrane potential (increased excitability). (medscape.com)
  • Here, we report that SOCE, peak Ca 2+ transient amplitude and muscle force production during repetitive stimulation are increased after exercise in parallel with the time course of TT association with SR-stacks. (elifesciences.org)
  • How will that affect skeletal muscle stimulation? (easynotecards.com)
  • Motor points have been identified for all major muscle groups for the purpose of functional electrical stimulation by physical therapists, in order to increase muscle power. (medscape.com)
  • Potassium (K), the main cation inside cells, plays roles in maintaining cellular osmolarity and acid-base equilibrium, as well as nerve stimulation transmission, and regulation of cardiac and muscle functions. (mdpi.com)
  • 2018) STAC3 incorporation into skeletal muscle triads occurs independent of the dihydropyridine receptor. (i-med.ac.at)
  • Campiglio, M. and Flucher, B.E. (2017) STAC3 stably interacts through its C1 domain with Ca V 1.1 in skeletal muscle triads. (i-med.ac.at)
  • Force-Velocity relationships is simply the relationship between the speed at which a muscle length changes (regulated by either external load or other muscles) to the amount of force that same muscle generates. (perch.fit)
  • Isotonic Contraction: The muscle generates a consistent tension despite a change in its length. (perch.fit)
  • Membrane permeability comparable to 8-Br-cAMP. (biolog.de)
  • These results indicate that TT association with SR-stacks enhances Orai1-dependent SOCE to optimize Ca 2+ dynamics and muscle contractile function during acute exercise. (elifesciences.org)
  • The Cirque du Soleil of Golgi membrane dynamics. (tamu.edu)
  • It was also found that JPH1 and JPH2 are differentially regulated in different muscles of rabbit, where the highest amount of both proteins was found in the extensor digitorum longus (EDL) muscle. (ucc.ie)
  • Long and parallel units of a muscle fiber composed of thick and thin myofilaments (contractile proteins called actin and myosin, and regulatory proteins called troponin and tropomyosin). (perch.fit)
  • Mitochondrial membrane biogenesis: phospholipids and proteins go hand in hand. (tamu.edu)
  • Forces that shape cells and tissues can be produced by the contraction of actin filament (F-actin) meshworks by the molecular motor Myosin II (myosin). (nature.com)
  • The cardiac conduction system (CCS) (also called the electrical conduction system of the heart ) [1] transmits the signals generated by the sinoatrial node - the heart 's pacemaker , to cause the heart muscle to contract , and pump blood through the body's circulatory system . (wikipedia.org)
  • The conduction system consists of specialized heart muscle cells , situated within the myocardium . (wikipedia.org)
  • Myocardial conduction cells initiate and propagate the action potential (the electrical impulse) that travels throughout the heart and triggers the contractions that propel the blood. (lumenlearning.com)
  • To better define acute muscle strain injuries, an imaging (MRI or ultrasound [US]) classification can be used, which considers the anatomical site, pattern and severity of the lesion in the acute stage. (aspetar.com)
  • Rationale: The anatomical substrate of skeletal muscle autonomic innervation has remained underappreciated since it was described many decades ago. (bvsalud.org)
  • BoNT hinders neural transmission by stalling the release of acetylcholine at the neural endplate and inhibits muscle contraction. (researchsquare.com)
  • This is likely because the reinnervation most often only resulted in partial nerve and endplate connections and the muscle's junctional folds were much more disorganized in aged rNLS8 mice. (biomedcentral.com)
  • T-tubules are closely associated with a specific region of the SR, known as the terminal cisternae in skeletal muscle, with a distance of roughly 12 nanometers, separating them. (wikipedia.org)
  • It was found that the RyR1 complex isolated from rat skeletal muscle co-purifies with the Growth factor receptor bound protein 2 (GRB2), very possibly via an interaction between the proline rich region of RyR1 and one of the SH3 domains located on the GRB2 protein. (ucc.ie)
  • Taken together, these results have implications for the regulation of RyR1 and JPH1 and 2 in skeletal muscle in both physiological and pathological states, and provide a newly characterised antibody to expand the field of JPH1 research. (ucc.ie)
  • Cylindrical muscles typically have greater mass at the center of the muscle, leading to a central body or muscle belly (eg, biceps brachii). (medscape.com)
  • A layer by layer look at the anatomy of skeletal muscle, adapted from Scientist Cindy [6]. (perch.fit)
  • In gross anatomy, the nerves to skeletal muscles are branches of mixed peripheral nerves. (medscape.com)
  • The quadratus lumborum (QL) muscles are the fundamental muscles responsible for abnormal posture in patients with myofascial pain syndrome (MPS). (researchsquare.com)
  • Necrotising doses of ECO further caused contraction clumps, loss of striations and procion staining with high serum CK. (aston.ac.uk)
  • Cell membranes are highly enriched in signaling receptors, transmembrane mechanosensors, pumps and channels, and, depending on their makeup, can recruit and retain a pool of mechanosensors important in the field of mechanobiology. (mechanobio.info)
  • We found that recovery was incomplete in aged mice relative to their younger treatment matched counterparts based on gross behavioral measures and physiological recordings from the animals' gastrocnemius (GC) muscles, despite muscle reinnervation by surviving MNs. (biomedcentral.com)
  • They consist of desmosomes, specialized linking proteoglycans, tight junctions, and large numbers of gap junctions that allow the passage of ions between the cells and help to synchronize the contraction. (lumenlearning.com)
  • In humans, the loss of muscle mass and accompanying degeneration of neuromuscular junctions (NMJs) is called sarcopenia and is a major cause of disability in the elderly [ 25 ]. (biomedcentral.com)
  • The functional benefits of exercise on SOCE, constitutive Ca 2+ entry and muscle force production were lost in mice with muscle-specific loss of Orai1 function. (elifesciences.org)
  • The heart is a functional syncytium as opposed to a skeletal muscle syncytium . (wikipedia.org)
  • The smallest, most basic and functional unit of a muscle that determines contraction. (perch.fit)
  • Clinical and functional assessment shows muscle strength and high speed/high resistance athletic activities are impaired with marked loss of muscle function. (aspetar.com)
  • The T tubules are only found at the Z discs, whereas in skeletal muscle, they are found at the junction of the A and I bands. (lumenlearning.com)
  • Cell damage was assessed using MTT assays, and the lactate dehydrogenase (LDH) release rate and flow cytometry were used to detect the accumulation of reactive oxygen species (ROS) and mitochondrial membrane potential respectively. (sdbonline.org)
  • An examination of JPH1 and 2 expression in mdx and wild type controls diaphragm, vastus lateralis, soleus and gastrocnemius muscle found no major differences in JPH1 abundance, while JPH2 was decreased in mdx gastrocnemius compared to wild type. (ucc.ie)
  • Here, we report that remodeled Cx43 protein forms Cx43 hemichannels in the lateral membrane of Dmd mdx cardiomyocytes and that the β-adrenergic agonist isoproterenol (Iso) aberrantly activates these hemichannels. (jci.org)
  • Subsequently, NDP was exploited to analyze sympathetic innervation in muscles of SOD1G93A mice, a preclinical ALS model. (bvsalud.org)
  • SN degeneration was also observed in muscles of MLC/SOD1G93A mice, with muscle specific expression of the SOD1G93A mutant gene. (bvsalud.org)
  • This article mainly focuses on the end organ of this complex interaction, the muscle fiber (myofiber). (medscape.com)
  • It is at the level of the myofiber where the basic contractile element of muscle, the sarcomere, is found. (medscape.com)
  • Benign (non-cancerous) tumors of the uterine muscle wall that may trigger irregular uterine bleeding. (ehd.org)
  • Currently, steroid therapy and assisted ventilation help combat skeletal muscle-related respiratory dysfunction and significantly prolong the lives of DMD patients. (jci.org)
  • Inhibition of Na + -K + -ATPase in skeletal muscle results in increased extracellular potassium and contributes to hyperkalemia. (medscape.com)
  • A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. (lookformedical.com)
  • These bind to a site on the cell membrane, producing reversible inhibition of the sodium (Na + )-potassium (K + )-adenosine triphosphatase (ATPase) pump. (medscape.com)
  • A well-known example of a bipennate muscle is the rectus femoris. (medscape.com)
  • Collagen type IV molecules assemble to form a sheet-like network which is involved in maintaining the structural integrity of basement membranes. (lookformedical.com)
  • Growth Hormone (GH) - stimulates cells to produce insulin-like growth factor 1 (IGF-1) which stimulate growth of muscle and bone. (tomsk.ru)
  • Contractile cells conduct impulses and are responsible for contractions that pump blood through the body. (lumenlearning.com)
  • In the introduction a brief outline of the possible mechanisms involved in the process of cellular necrosis with particular emphasis on skeletal muscle necrosis after antiChE is discussed. (aston.ac.uk)
  • These muscles all contain a relatively high percentage of type II fibres, are arranged in a pennate muscle architecture and cross two joints. (aspetar.com)
  • Like a neuron, a given myocardial cell has a negative membrane potential when at rest. (wikipedia.org)
  • When these hormones bind to a receptor, called a beta 1 adrenoceptor, located on the cell membrane, they produce a series of reactions (known as a cyclic AMP pathway) that produces an enzyme called protein kinase A (PKA). (wikipedia.org)
  • These results also suggest the coupling of RACK1 to muscle unfolded protein response during SC activation. (sdbonline.org)
  • Muscle strains occur most often at the musculotendinous junction as a consequence of indirect trauma. (aspetar.com)
  • Oedema and haemorrhage of the muscle or musculotendinous junction (MTJ) may extend between muscle groups along the fascial planes. (aspetar.com)
  • A junction between two adjoining cells is marked by a critical structure called an intercalated disc , which helps support the synchronized contraction of the muscle. (lumenlearning.com)
  • These contractile elements are virtually identical to skeletal muscle. (lumenlearning.com)
  • The internalized ventral cells give rise to the mesoderm that differentiates into muscle and other internal cell types such as the fat body, macrophages or lymph glands. (nature.com)
  • Our results indicate that SNs are additional cell types compromised in ALS and suggest that dysfunctional SOD1G93A muscles affect their sympathetic innervation. (bvsalud.org)
  • In this case, muscle strains, which are very common in sprinters and jumpers such as high jumpers, long jumpers, sprinters, long distance runners and tennis players, occur because of an indirect trauma and application of excessive tensile forces 6 . (aspetar.com)