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are a number of terms used in the naming of muscles including those relating to size, shape, action, location, their orientation, and their number of heads. Fiber types. Broadly there are two types of muscle fiber: Type I, which is slow, and Type II which are fast. Type II has two divisions of type IIA (oxidative), and type IIX (glycolytic), giving three main fiber types. These fibers have relatively distinct metabolic, contractile, and motor unit properties. The table below differentiates these types of properties. These types of properties—while they are partly dependent on the properties of individual fibers—tend

Skeletal muscle

to be relevant and measured at the level of the motor unit, rather than individual fiber. Fiber color. Traditionally, fibers were categorized depending on their varying color, which is a reflection of myoglobin content. Type I fibers appear red due to the high levels of myoglobin. Red muscle fibers tend to have more mitochondria and greater local capillary density. These fibers are more suited for endurance and are slow to fatigue because they use oxidative metabolism to generate ATP (adenosine triphosphate). Less oxidative Type II fibers are white due to relatively low myoglobin and a reliance on glycolytic enzymes. Twitch

Skeletal muscle

speed. Fibers can also be classified on their twitch capabilities, into fast and slow twitch. These traits largely, but not completely, overlap the classifications based on color, ATPase, or MHC. Some authors define a fast twitch fiber as one in which the myosin can split ATP very quickly. These mainly include the ATPase type II and MHC type II fibers. However, fast twitch fibers also demonstrate a higher capability for electrochemical transmission of action potentials and a rapid level of calcium release and uptake by the sarcoplasmic reticulum. The fast twitch fibers rely on a well-developed, anaerobic, short term

Skeletal muscle

, glycolytic system for energy transfer and can contract and develop tension at 2–3 times the rate of slow twitch fibers. Fast twitch muscles are much better at generating short bursts of strength or speed than slow muscles, and so fatigue more quickly. The slow twitch fibers generate energy for ATP re-synthesis by means of a long term system of aerobic energy transfer. These mainly include the ATPase type I and MHC type I fibers. They tend to have a low activity level of ATPase, a slower speed of contraction with a less well developed glycolytic capacity. Fibers that become

Skeletal muscle

slow-twitch develop greater numbers of mitochondria and capillaries making them better for prolonged work. Individual muscles tend to be a mixture of various fiber types, but their proportions vary depending on the actions of that muscle. For instance, in humans, the quadriceps muscles contain ~52% type I fibers, while the soleus is ~80% type I. The orbicularis oculi muscle of the eye is only ~15% type I. Motor units within the muscle, however, have minimal variation between the fibers of that unit. It is this fact that makes the size principal of motor unit recruitment viable. The total number

Skeletal muscle

of skeletal muscle fibers has traditionally been thought not to change. It is believed there are no sex or age differences in fiber distribution; however, proportions of fiber types vary considerably from muscle to muscle and person to person. Among different species there is a much variation in the proportions of muscle fiber types. Sedentary men and women (as well as young children) have 45% type II and 55% type I fibers. People at the higher end of any sport tend to demonstrate patterns of fiber distribution e.g. endurance athletes show a higher level of type I fibers. Sprint athletes

Skeletal muscle

, on the other hand, require large numbers of type IIX fibers. Middle-distance event athletes show approximately equal distribution of the two types. This is also often the case for power athletes such as throwers and jumpers. It has been suggested that various types of exercise can induce changes in the fibers of a skeletal muscle. It is thought that if you perform endurance type events for a sustained period of time, some of the type IIX fibers transform into type IIA fibers. However, there is no consensus on the subject. It may well be that the type IIX fibers

Skeletal muscle

show enhancements of the oxidative capacity after high intensity endurance training which brings them to a level at which they are able to perform oxidative metabolism as effectively as slow twitch fibers of untrained subjects. This would be brought about by an increase in mitochondrial size and number and the associated related changes, not a change in fiber type. Fiber typing methods. There are numerous methods employed for fiber-typing, and confusion between the methods is common among non-experts. Two commonly confused methods are histochemical staining for myosin ATPase activity and immunohistochemical staining for myosin heavy chain (MHC) type

Skeletal muscle

. Myosin ATPase activity is commonly—and correctly—referred to as simply "fiber type", and results from the direct assaying of ATPase activity under various conditions (e.g. pH). Myosin heavy chain staining is most accurately referred to as "MHC fiber type", e.g. "MHC IIa fibers", and results from determination of different MHC isoforms. These methods are closely related physiologically, as the MHC type is the primary determinant of ATPase activity. However, neither of these typing methods is directly metabolic in nature; they do not directly address oxidative or glycolytic capacity of the fiber. When "type I" or "type II" fibers are

Skeletal muscle

referred to generically, this most accurately refers to the sum of numerical fiber types (I vs. II) as assessed by myosin ATPase activity staining (e.g. "type II" fibers refers to type IIA + type IIAX + type IIXA ... etc.). Below is a table showing the relationship between these two methods, limited to fiber types found in humans. Subtype capitalization is used in fiber typing vs. MHC typing, and some ATPase types actually contain multiple MHC types. Also, a subtype B or b is not expressed in humans by either method. Early researchers believed humans to express a MHC IIb, which

Skeletal muscle

led to the ATPase classification of IIB. However, later research showed that the human MHC IIb was in fact IIx, indicating that the IIB is better named IIX. IIb is expressed in other mammals, so is still accurately seen (along with IIB) in the literature. Non human fiber types include true IIb fibers, IIc, IId, etc. Further fiber typing methods are less formally delineated, and exist on more of a spectrum. They tend to be focused more on metabolic and functional capacities (i.e., oxidative vs. glycolytic, fast vs. slow contraction time). As noted above, fiber typing by ATPase or MHC

Skeletal muscle

does not directly measure or dictate these parameters. However, many of the various methods are mechanistically linked, while others are correlated "in vivo". For instance, ATPase fiber type is related to contraction speed, because high ATPase activity allows faster crossbridge cycling. While ATPase activity is only one component of contraction speed, Type I fibers are "slow", in part, because they have low speeds of ATPase activity in comparison to Type II fibers. However, measuring contraction speed is not the same as ATPase fiber typing. Microanatomy. Skeletal muscle exhibits a distinctive banding pattern when viewed under the microscope due to the

Skeletal muscle

arrangement of two contractile proteins myosin, and actin – that are two of the myofilaments in the myofibrils. The myosin forms the thick filaments, and actin forms the thin filaments, and are arranged in repeating units called sarcomeres. The interaction of both proteins results in muscle contraction. The sarcomere is attached to other organelles such as the mitochondria by intermediate filaments in the cytoskeleton. The costamere attaches the sarcomere to the sarcolemma. Every single organelle and macromolecule of a muscle fiber is arranged to ensure that it meets desired functions. The cell membrane is called the sarcolemma with the cytoplasm known

Skeletal muscle

as the sarcoplasm. In the sarcoplasm are the myofibrils. The myofibrils are long protein bundles about one micrometer in diameter. Pressed against the inside of the sarcolemma are the unusual flattened myonuclei. Between the myofibrils are the mitochondria. While the muscle fiber does not have smooth endoplasmic cisternae, it contains sarcoplasmic reticulum. The sarcoplasmic reticulum surrounds the myofibrils and holds a reserve of the calcium ions needed to cause a muscle contraction. Periodically, it has dilated end sacs known as terminal cisternae. These cross the muscle fiber from one side to the other. In between two terminal cisternae is a

Skeletal muscle

tubular infolding called a transverse tubule (T tubule). T tubules are the pathways for action potentials to signal the sarcoplasmic reticulum to release calcium, causing a muscle contraction. Together, two terminal cisternae and a transverse tubule form a triad. Development. All muscles are derived from paraxial mesoderm. During embryonic development in the process of somitogenesis the paraxial mesoderm is divided along the embryo's length to form somites, corresponding to the segmentation of the body most obviously seen in the vertebral column. Each somite has three divisions, sclerotome (which forms vertebrae), dermatome (which forms skin), and myotome (which forms muscle

Skeletal muscle

). The myotome is divided into two sections, the epimere and hypomere, which form epaxial and hypaxial muscles, respectively. The only epaxial muscles in humans are the erector spinae and small vertebral muscles, and are innervated by the dorsal rami of the spinal nerves. All other muscles, including those of the limbs are hypaxial, and innervated by the ventral rami of the spinal nerves. During development, myoblasts (muscle progenitor cells) either remain in the somite to form muscles associated with the vertebral column or migrate out into the body to form all other muscles. Myoblast migration is preceded by the formation

Skeletal muscle

of connective tissue frameworks, usually formed from the somatic lateral plate mesoderm. Myoblasts follow chemical signals to the appropriate locations, where they fuse into elongated multinucleated skeletal muscle cells. Between the tenth and the eighteenth weeks of gestation, all muscle cells have fast myosin heavy chains; two myotube types become distinguished in the developing fetus – both expressing fast chains but one expressing fast and slow chains. Between 10 and 40 per cent of the fibers express the slow myosin chain. Fiber types are established during embryonic development and are remodelled later in the adult by neural and hormonal influences. The

Skeletal muscle

population of satellite cells present underneath the basal lamina is necessary for the postnatal development of muscle cells. Function. The primary function of muscle is contraction. Following contraction, skeletal muscle functions as an endocrine organ by secreting myokines – a wide range of cytokines and other peptides that act as signalling molecules. Myokines in turn are believed to mediate the health benefits of exercise. Myokines are secreted into the bloodstream after muscle contraction. Interleukin 6 (IL-6) is the most studied myokine, other muscle contraction-induced myokines include BDNF, FGF21, and SPARC. Muscle also functions to produce body heat. Muscle contraction is

Skeletal muscle

responsible for producing 85% of the body's heat. This heat produced is as a by-product of muscular activity, and is mostly wasted. As a homeostatic response to extreme cold, muscles are signaled to trigger contractions of shivering in order to generate heat. Contraction. Contraction is achieved by the muscle's structural unit the muscle fiber, and by its functional unit, the motor unit. Muscle fibers are excitable cells stimulated by motor neurons. The motor unit consists of a motor neuron and the many fibers that it makes contact with. A single muscle is stimulated by many motor units

Skeletal muscle

. Muscle fibers are subject to depolarization by the neurotransmitter acetylcholine, released by the motor neurons at the neuromuscular junctions. In addition to the actin and myosin myofilaments in the myofibrils that make up the contractile sarcomeres, there are two other important regulatory proteins – troponin and tropomyosin, that make muscle contraction possible. These proteins are associated with actin and cooperate to prevent its interaction with myosin. Once a cell is sufficiently stimulated, the cell's sarcoplasmic reticulum releases ionic calcium (Ca), which then interacts with the regulatory protein troponin. Calcium-bound troponin undergoes a conformational change that leads to the movement

Skeletal muscle

of tropomyosin, subsequently exposing the myosin-binding sites on actin. This allows for myosin and actin ATP-dependent cross-bridge cycling and shortening of the muscle. Excitation-contraction coupling. Excitation contraction coupling is the process by which a muscular action potential in the muscle fiber causes the myofibrils to contract. This process relies on a direct coupling between the sarcoplasmic reticulum calcium release channel RYR1 (ryanodine receptor 1), and voltage-gated L-type calcium channels (identified as dihydropyridine receptors, DHPRs). DHPRs are located on the sarcolemma (which includes the surface sarcolemma and the transverse tubules), while the RyRs reside across

Skeletal muscle

the SR membrane. The close apposition of a transverse tubule and two SR regions containing RyRs is described as a triad and is predominantly where excitation–contraction coupling takes place. Excitation–contraction coupling occurs when depolarization of skeletal muscle cell results in a muscle action potential, which spreads across the cell surface and into the muscle fiber's network of T-tubules, thereby depolarizing the inner portion of the muscle fiber. Depolarization of the inner portions activates dihydropyridine receptors in the terminal cisternae, which are in close proximity to ryanodine receptors in the adjacent sarcoplasmic reticulum. The activated dihydropyridine receptors

Skeletal muscle

physically interact with ryanodine receptors to activate them via foot processes (involving conformational changes that allosterically activates the ryanodine receptors). As the ryanodine receptors open, is released from the sarcoplasmic reticulum into the local junctional space and diffuses into the bulk cytoplasm to cause a calcium spark. Note that the sarcoplasmic reticulum has a large calcium buffering capacity partially due to a calcium-binding protein called calsequestrin. The near synchronous activation of thousands of calcium sparks by the action potential causes a cell-wide increase in calcium giving rise to the upstroke of the calcium transient. The released into the

Skeletal muscle

cytosol binds to Troponin C by the actin filaments, to allow crossbridge cycling, producing force and, in some situations, motion. The sarco/endoplasmic reticulum calcium-ATPase (SERCA) actively pumps back into the sarcoplasmic reticulum. As declines back to resting levels, the force declines and relaxation occurs. Muscle movement. The efferent leg of the peripheral nervous system is responsible for conveying commands to the muscles and glands, and is ultimately responsible for voluntary movement. Nerves move muscles in response to voluntary and autonomic (involuntary) signals from the brain. Deep muscles, superficial muscles, and internal muscles all correspond with dedicated regions in

Skeletal muscle

the primary motor cortex of the brain, directly anterior to the central sulcus that divides the frontal and parietal lobes. In addition, muscles react to reflexive nerve stimuli that do not always send signals all the way to the brain. In this case, the signal from the afferent fiber does not reach the brain, but produces the reflexive movement by direct connections with the efferent nerves in the spine. However, the majority of muscle activity is volitional, and the result of complex interactions between various areas of the brain. Nerves that control skeletal muscles in mammals correspond with neuron groups

Skeletal muscle

along the primary motor cortex of the brain's cerebral cortex. Commands are routed through the basal ganglia and are modified by input from the cerebellum before being relayed through the pyramidal tract to the spinal cord and from there to the motor end plate at the muscles. Along the way, feedback, such as that of the extrapyramidal system contribute signals to influence muscle tone and response. Deeper muscles such as those involved in posture often are controlled from nuclei in the brain stem and basal ganglia. Proprioception. In skeletal muscles, muscle spindles convey information about the degree of muscle

Skeletal muscle

length and stretch to the central nervous system to assist in maintaining posture and joint position. The sense of where our bodies are in space is called proprioception, the perception of body awareness, the "unconscious" awareness of where the various regions of the body are located at any one time. Several areas in the brain coordinate movement and position with the feedback information gained from proprioception. The cerebellum and red nucleus in particular continuously sample position against movement and make minor corrections to assure smooth motion. Energy consumption. Muscular activity accounts for much of the body's energy consumption. All

Skeletal muscle

muscle cells produce adenosine triphosphate (ATP) molecules which are used to power the movement of the myosin heads. Muscles have a short-term store of energy in the form of creatine phosphate which is generated from ATP and can regenerate ATP when needed with creatine kinase. Muscles also keep a storage form of glucose in the form of glycogen. Glycogen can be rapidly converted to glucose when energy is required for sustained, powerful contractions. Within the voluntary skeletal muscles, the glucose molecule can be metabolized anaerobically in a process called glycolysis which produces two ATP and two lactic acid molecules

Skeletal muscle

in the process (note that in aerobic conditions, lactate is not formed; instead pyruvate is formed and transmitted through the citric acid cycle). Muscle cells also contain globules of fat, which are used for energy during aerobic exercise. The aerobic energy systems take longer to produce the ATP and reach peak efficiency, and requires many more biochemical steps, but produces significantly more ATP than anaerobic glycolysis. Cardiac muscle on the other hand, can readily consume any of the three macronutrients (protein, glucose and fat) aerobically without a 'warm up' period and always extracts the maximum ATP yield from any molecule

Skeletal muscle

involved. The heart, liver and red blood cells will also consume lactic acid produced and excreted by skeletal muscles during exercise. Skeletal muscle uses more calories than other organs. At rest it consumes 54.4 kJ/kg (13.0 kcal/kg) per day. This is larger than adipose tissue (fat) at 18.8 kJ/kg (4.5 kcal/kg), and bone at 9.6 kJ/kg (2.3 kcal/kg). Efficiency. The efficiency of human muscle has been measured (in the context of rowing and cycling) at 18% to 26%. The efficiency is defined as the ratio of mechanical work output to the total metabolic cost

Skeletal muscle

, as can be calculated from oxygen consumption. This low efficiency is the result of about 40% efficiency of generating ATP from food energy, losses in converting energy from ATP into mechanical work inside the muscle, and mechanical losses inside the body. The latter two losses are dependent on the type of exercise and the type of muscle fibers being used (fast-twitch or slow-twitch). For an overall efficiency of 20 percent, one watt of mechanical power is equivalent to 4.3 kcal per hour. For example, one manufacturer of rowing equipment calibrates its rowing ergometer to count burned calories as

Skeletal muscle

equal to four times the actual mechanical work, plus 300 kcal per hour, this amounts to about 20 percent efficiency at 250 watts of mechanical output. The mechanical energy output of a cyclic contraction can depend upon many factors, including activation timing, muscle strain trajectory, and rates of force rise & decay. These can be synthesized experimentally using work loop analysis. Muscle strength. Muscle strength is a result of three overlapping factors: "physiological strength" (muscle size, cross sectional area, available crossbridging, responses to training), "neurological strength" (how strong or weak is the signal that tells the muscle to contract), and "mechanical

Skeletal muscle

strength" (muscle's force angle on the lever, moment arm length, joint capabilities). Vertebrate muscle typically produces approximately of force per square centimeter of muscle cross-sectional area when isometric and at optimal length. Some invertebrate muscles, such as in crab claws, have much longer sarcomeres than vertebrates, resulting in many more sites for actin and myosin to bind and thus much greater force per square centimeter at the cost of much slower speed. The force generated by a contraction can be measured non-invasively using either mechanomyography or phonomyography, be measured in vivo using tendon strain (if a prominent

Skeletal muscle

tendon is present), or be measured directly using more invasive methods. The strength of any given muscle, in terms of force exerted on the skeleton, depends upon length, shortening speed, cross sectional area, pennation, sarcomere length, myosin isoforms, and neural activation of motor units. Significant reductions in muscle strength can indicate underlying pathology, with the chart at right used as a guide. The "maximum holding time" for a contracted muscle depends on its supply of energy and is stated by Rohmert's law to exponentially decay from the beginning of exertion. The "strongest" human muscle. Since three factors affect muscular

Skeletal muscle

strength simultaneously and muscles never work individually, it is misleading to compare strength in individual muscles, and state that one is the "strongest". But below are several muscles whose strength is noteworthy for different reasons. Force generation. Muscle force is proportional to physiological cross-sectional area (PCSA), and muscle velocity is proportional to muscle fiber length. The torque around a joint, however, is determined by a number of biomechanical parameters, including the distance between muscle insertions and pivot points, muscle size and architectural gear ratio. Muscles are normally arranged in opposition so that when one group of muscles contracts, another

Skeletal muscle

group relaxes or lengthens. Antagonism in the transmission of nerve impulses to the muscles means that it is impossible to fully stimulate the contraction of two antagonistic muscles at any one time. During ballistic motions such as throwing, the antagonist muscles act to 'brake' the agonist muscles throughout the contraction, particularly at the end of the motion. In the example of throwing, the chest and front of the shoulder (anterior deltoid) contract to pull the arm forward, while the muscles in the back and rear of the shoulder (posterior deltoid) also contract and undergo eccentric contraction to slow the motion

Skeletal muscle

down to avoid injury. Part of the training process is learning to relax the antagonist muscles to increase the force input of the chest and anterior shoulder. Contracting muscles produce vibration and sound. Slow twitch fibers produce 10 to 30 contractions per second (10 to 30 Hz). Fast twitch fibers produce 30 to 70 contractions per second (30 to 70 Hz). The vibration can be witnessed and felt by highly tensing one's muscles, as when making a firm fist. The sound can be heard by pressing a highly tensed muscle against the ear, again a firm fist is a

Skeletal muscle

good example. The sound is usually described as a rumbling sound. Some individuals can voluntarily produce this rumbling sound by contracting the tensor tympani muscle of the middle ear. The rumbling sound can also be heard when the neck or jaw muscles are highly tensed. Signal transduction pathways. Skeletal muscle fiber-type phenotype in adult animals is regulated by several independent signaling pathways. These include pathways involved with the Ras/mitogen-activated protein kinase (MAPK) pathway, calcineurin, calcium/calmodulin-dependent protein kinase IV, and the peroxisome proliferator γ coactivator 1 (PGC-1). The Ras/MAPK signaling pathway links the motor neurons

Skeletal muscle

and signaling systems, coupling excitation and transcription regulation to promote the nerve-dependent induction of the slow program in regenerating muscle. Calcineurin, a Ca/calmodulin-activated phosphatase implicated in nerve activity-dependent fiber-type specification in skeletal muscle, directly controls the phosphorylation state of the transcription factor NFAT, allowing for its translocation to the nucleus and leading to the activation of slow-type muscle proteins in cooperation with myocyte enhancer factor 2 (MEF2) proteins and other regulatory proteins. Ca2+/calmodulin-dependent protein kinase activity is also upregulated by slow motor neuron activity, possibly because it amplifies the slow-type calcineurin-generated

Skeletal muscle

responses by promoting MEF2 transactivator functions and enhancing oxidative capacity through stimulation of mitochondrial biogenesis. Contraction-induced changes in intracellular calcium or reactive oxygen species provide signals to diverse pathways that include the MAPKs, calcineurin and calcium/calmodulin-dependent protein kinase IV to activate transcription factors that regulate gene expression and enzyme activity in skeletal muscle. PGC1-α (PPARGC1A), a transcriptional coactivator of nuclear receptors important to the regulation of a number of mitochondrial genes involved in oxidative metabolism, directly interacts with MEF2 to synergistically activate selective slow twitch (ST) muscle genes and also serves as a target for calcineurin

Skeletal muscle

signaling. A peroxisome proliferator-activated receptor δ (PPARδ)-mediated transcriptional pathway is involved in the regulation of the skeletal muscle fiber phenotype. Mice that harbor an activated form of PPARd display an "endurance" phenotype, with a coordinated increase in oxidative enzymes and mitochondrial biogenesis and an increased proportion of ST fibers. Thus—through functional genomics—calcineurin, calmodulin-dependent kinase, PGC-1α, and activated PPARδ form the basis of a signaling network that controls skeletal muscle fiber-type transformation and metabolic profiles that protect against insulin resistance and obesity. The transition from aerobic to anaerobic metabolism during intense work requires that several systems

Skeletal muscle

are rapidly activated to ensure a constant supply of ATP for the working muscles. These include a switch from fat-based to carbohydrate-based fuels, a redistribution of blood flow from nonworking to exercising muscles, and the removal of several of the by-products of anaerobic metabolism, such as carbon dioxide and lactic acid. Some of these responses are governed by transcriptional control of the fast twitch (FT) glycolytic phenotype. For example, skeletal muscle reprogramming from an ST glycolytic phenotype to an FT glycolytic phenotype involves the Six1/Eya1 complex, composed of members of the Six protein family. Moreover, the

Skeletal muscle

hypoxia-inducible factor 1-α (HIF1A) has been identified as a master regulator for the expression of genes involved in essential hypoxic responses that maintain ATP levels in cells. Ablation of HIF-1α in skeletal muscle was associated with an increase in the activity of rate-limiting enzymes of the mitochondria, indicating that the citric acid cycle and increased fatty acid oxidation may be compensating for decreased flow through the glycolytic pathway in these animals. However, hypoxia-mediated HIF-1α responses are also linked to the regulation of mitochondrial dysfunction through the formation of excessive reactive oxygen species in mitochondria. Other pathways

Skeletal muscle

also influence adult muscle character. For example, physical force inside a muscle fiber may release the transcription factor serum response factor from the structural protein titin, leading to altered muscle growth. Exercise. Physical exercise is often recommended as a means of improving motor skills, fitness, muscle and bone strength, and joint function. Exercise has several effects upon muscles, connective tissue, bone, and the nerves that stimulate the muscles. One such effect is muscle hypertrophy, an increase in size of muscle due to an increase in the number of muscle fibers or cross-sectional area of myofibrils. Muscle changes depend on

Skeletal muscle

the type of exercise used. Generally, there are two types of exercise regimes, aerobic and anaerobic. Aerobic exercise (e.g. marathons) involves activities of low intensity but long duration, during which the muscles used are below their maximal contraction strength. Aerobic activities rely on aerobic respiration (i.e. citric acid cycle and electron transport chain) for metabolic energy by consuming fat, protein, carbohydrates, and oxygen. Muscles involved in aerobic exercises contain a higher percentage of Type I (or slow-twitch) muscle fibers, which primarily contain mitochondrial and oxidation enzymes associated with aerobic respiration. On the contrary, anaerobic exercise is associated with exercise

Skeletal muscle

or short duration but high intensity (e.g. sprinting and weight lifting). The anaerobic activities predominately use Type II, fast-twitch, muscle fibers. Type II muscle fibers rely on glucogenesis for energy during anaerobic exercise. During anaerobic exercise, type II fibers consume little oxygen, protein and fat, produces large amounts of lactic acid and are fatigable. Many exercises are partially aerobic and anaerobic; for example, soccer and rock climbing. The presence of lactic acid has an inhibitory effect on ATP generation within the muscle. It can even stop ATP production if the intracellular concentration becomes too high. However, endurance training mitigates

Skeletal muscle

the buildup of lactic acid through increased capillarization and myoglobin. This increases the ability to remove waste products, like lactic acid, out of the muscles in order to not impair muscle function. Once moved out of muscles, lactic acid can be used by other muscles or body tissues as a source of energy, or transported to the liver where it is converted back to pyruvate. In addition to increasing the level of lactic acid, strenuous exercise results in the loss of potassium ions in muscle. This may facilitate the recovery of muscle function by protecting against fatigue. Delayed onset muscle

Skeletal muscle

soreness is pain or discomfort that may be felt one to three days after exercising and generally subsides two to three days later. Once thought to be caused by lactic acid build-up, a more recent theory is that it is caused by tiny tears in the muscle fibers caused by eccentric contraction, or unaccustomed training levels. Since lactic acid disperses fairly rapidly, it could not explain pain experienced days after exercise. Clinical significance. Muscle disease. Diseases of skeletal muscle are termed myopathies, while diseases of nerves are called neuropathies. Both can affect muscle function or cause muscle pain, and

Skeletal muscle

fall under the umbrella of neuromuscular disease. The cause of many myopathies is attributed to mutations in the various associated muscle proteins. Some inflammatory myopathies include polymyositis and inclusion body myositis Neuromuscular diseases affect the muscles and their nervous control. In general, problems with nervous control can cause spasticity or paralysis, depending on the location and nature of the problem. A number of movement disorders are caused by neurological disorders such as Parkinson's disease and Huntington's disease where there is central nervous system dysfunction. Symptoms of muscle diseases may include weakness, spasticity, myoclonus and myalgia. Diagnostic procedures that

Skeletal muscle

may reveal muscular disorders include testing creatine kinase levels in the blood and electromyography (measuring electrical activity in muscles). In some cases, muscle biopsy may be done to identify a myopathy, as well as genetic testing to identify DNA abnormalities associated with specific myopathies and dystrophies. A non-invasive elastography technique that measures muscle noise is undergoing experimentation to provide a way of monitoring neuromuscular disease. The sound produced by a muscle comes from the shortening of actomyosin filaments along the axis of the muscle. During contraction, the muscle shortens along its length and expands across its width, producing vibrations

Skeletal muscle

at the surface. Hypertrophy. Independent of strength and performance measures, muscles can be induced to grow larger by a number of factors, including hormone signaling, developmental factors, strength training, and disease. Contrary to popular belief, the number of muscle fibres cannot be increased through exercise. Instead, muscles grow larger through a combination of muscle cell growth as new protein filaments are added along with additional mass provided by undifferentiated satellite cells alongside the existing muscle cells. Biological factors such as age and hormone levels can affect muscle hypertrophy. During puberty in males, hypertrophy occurs at an accelerated rate as

Skeletal muscle

the levels of growth-stimulating hormones produced by the body increase. Natural hypertrophy normally stops at full growth in the late teens. As testosterone is one of the body's major growth hormones, on average, men find hypertrophy much easier to achieve than women. Taking additional testosterone or other anabolic steroids will increase muscular hypertrophy. Muscular, spinal and neural factors all affect muscle building. Sometimes a person may notice an increase in strength in a given muscle even though only its opposite has been subject to exercise, such as when a bodybuilder finds her left biceps stronger after completing a

Skeletal muscle

regimen focusing only on the right biceps. This phenomenon is called cross education. Atrophy. Every day between one and two percent of muscle is broken down and rebuilt. Inactivity, malnutrition, disease, and aging can increase the breakdown leading to muscle atrophy or sarcopenia. Sarcopenia is commonly an age-related process that can cause frailty and its consequences. A decrease in muscle mass may be accompanied by a smaller number and size of the muscle cells as well as lower protein content. Human spaceflight, involving prolonged periods of immobilization and weightlessness is known to result in muscle weakening and atrophy resulting

Skeletal muscle

in a loss of as much as 30% of mass in some muscles. Such consequences are also noted in some mammals following hibernation. Many diseases and conditions including cancer, AIDS, and heart failure can cause muscle loss known as cachexia. Research. Myopathies have been modeled with cell culture systems of muscle from healthy or diseased tissue biopsies. Another source of skeletal muscle and progenitors is provided by the directed differentiation of pluripotent stem cells. Research on skeletal muscle properties uses many techniques. Electrical muscle stimulation is used to determine force and contraction speed at different frequencies related to fiber-type

Skeletal muscle

composition and mix within an individual muscle group. In vitro muscle testing is used for more complete characterization of muscle properties. The electrical activity associated with muscle contraction is measured via electromyography (EMG). Skeletal muscle has two physiological responses: relaxation and contraction. The mechanisms for which these responses occur generate electrical activity measured by EMG. Specifically, EMG can measure the action potential of a skeletal muscle, which occurs from the hyperpolarization of the motor axons from nerve impulses sent to the muscle. EMG is used in research for determining if the skeletal muscle of interest is being activated, the amount

Skeletal muscle

of force generated, and an indicator of muscle fatigue. The two types of EMG are intra-muscular EMG and the most common, surface EMG. The EMG signals are much greater when a skeletal muscle is contracting verses relaxing. However, for smaller and deeper skeletal muscles the EMG signals are reduced and therefore are viewed as a less valued technique for measuring the activation. In research using EMG, a maximal voluntary contraction (MVC) is commonly performed on the skeletal muscle of interest, to have reference data for the rest of the EMG recordings during the main experimental testing for that same

Skeletal muscle

skeletal muscle. Research into the development of artificial muscles includes the use of electroactive polymers. Skeletal muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system that are mostly attached by tendons to bones of the skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle tissue, and are often known as muscle fibers. The muscle tissue of a skeletal muscle is striated – having a striped appearance due to the arrangement of the sarcomeres. Skeletal muscles are voluntary muscles under the control of the somatic nervous system. The

Skeletal muscle

Santo Cilauro Santo Cilauro Santo Luigi Cilauro (born 25 November 1961) is an Australian comedian, television and feature film producer, screenwriter, actor, author and cameraman who is also a co-founder of "The D-Generation". Known as the weatherman in "Frontline", he is also an author and former radio presenter on the Triple M Network, and achieved worldwide fame with the viral video "Elektronik Supersonik". Early life. Cilauro was born in 1961 in Melbourne, Australia to parents of Italian descent. Cilauro attended the University of Melbourne in the 1980s and graduated with a Bachelor of Arts and a Bachelor of Laws in

Santo Cilauro

1987. Acting and production work. Cilauro started collaborating with Rob Sitch and Tom Gleisner in comedy theatre productions and tours. He is one of the co-founders of "The D-Generation". Cilauro wrote for, and performed in, the troupe's show during its 1986–87 run on ABC TV (which also led to the album "The Satanic Sketches"). Cilauro continued as a member of the D-Gen when the team hosted their "Breakfast Show" on Triple M radio (1986–1992), appearing as the simple-minded "Wayne from St. Albans" and "Gino Tagliatoni" amongst other roles. Cilauro was a writer/performer on the

Santo Cilauro

D-Generation's 1992–1993 sketch comedy "The Late Show", appearing on such segments as "Graham & the Colonel", "The Oz Brothers" and "Jeff & Terry Bailey". After the second and last season of "The Late Show", Cilauro starred as Stix in the 1994 ABC cop show satire "Funky Squad", which he also co-created and served as one of the writer/producer/directors. He went on to help set up the Working Dog production company and was one of the writer/producer/directors of "Frontline" (1994–97), in which he also had a recurring onscreen role as weatherman Geoffrey Salter. Since then, Cilauro

Santo Cilauro

co-wrote Working Dog's popular films "The Castle" (1997) and "The Dish" (2000) and appeared as a regular member (and occasional host) of the 1998–2003 Network Ten programme "The Panel". Cilauro has been an executive producer of several Working Dog productions, including "The Panel", "A River Somewhere" (1997–98), and "All Aussie Adventures" (2001–02). He played the Head of Market Research, Theo Tsolakis, on "The Hollowmen" (2008), a series which Cilauro co-wrote and co-produced. Cilauro also played IT technician Griffin on the Shaun Micallef sitcom "Welcher & Welcher" (2003) and K2 on the 1996 Working Dog radio sketch "Johnny

Santo Cilauro

Swank". During the 2010 FIFA World Cup, he hosted a nightly comedy/variety show called "Santo, Sam and Ed's Cup Fever!" live from Melbourne alongside Ed Kavalee and Sam Pang. In 2014 Cilauro joined his Working Dog colleagues, Sitch and Gleisner to stage the group's first play, "The Speechmaker". Zladko Vladcik. Cilauro, along with Rob Sitch and Tom Gleisner, created the popular Internet phenomenon character Zladko "ZLAD!" Vladcik, a Molvanian synth-pop musician. Zlad was performed by Cilauro to accompany the Jetlag Travel Guide to Molvanîa. Cilauro was, with Sitch and Gleisner, co-author of the Jetlag Travel

Santo Cilauro

Guides to Molvanîa, Phaic Tăn and San Sombrèro. Two music videos were performed by Cilauro as Zladko, for "Elektronik – Supersonik" and "I Am The Anti-Pope". Santo Cilauro Santo Luigi Cilauro (born 25 November 1961) is an Australian comedian, television and feature film producer, screenwriter, actor, author and cameraman who is also a co-founder of "The D-Generation". Known as the weatherman in "Frontline", he is also an author and former radio presenter on the Triple M Network, and achieved worldwide fame with the viral video "Elektronik Supersonik". Early life. Cilauro was born in 1961 in Melbourne, Australia to

Santo Cilauro

Hopkinton, Massachusetts Hopkinton, Massachusetts Hopkinton is a town in Middlesex County, Massachusetts, United States, less than west of Boston. The town is best known as the starting point of the Boston Marathon, held annually on Patriots' Day in April, and as the headquarters for the enterprise-oriented Dell EMC. At the 2020 census, the town had a population of 18,758. The U.S. Census recognizes a village within the town known as Woodville, reporting a population of 2,651 as of the 2020 census. History. The town of Hopkinton was incorporated on December 13, 1715. Hopkinton was named for an early colonist of Connecticut

Hopkinton, Massachusetts

, Edward Hopkins, who left a large sum of money to be invested in land in New England, the proceeds of which were to be used for the benefit of Harvard University. The trustees of Harvard purchased 12 500 acres of land from the Native American residents with money from the fund and incorporated the area, naming it in honor of its benefactor. Grain was the first production crop grown in the area, while fruit and dairy industries were developed later. Agriculture predominated until 1840 when the boot and shoe industries were introduced into the town. By 1850 eleven boot and

Hopkinton, Massachusetts

shoe factories were established in Hopkinton. Fires in 1882 and the migration of those industries to other parts of the country eliminated these industries from Hopkinton. There are 215 Hopkinton properties listed in the State Register of Historic Places. The majority, 187, are located within the Cedar Swamp Archaeological District in Hopkinton and Westborough. The properties are also listed in the National Register of Historic Places. Twenty-three properties are included within the Hopkinton Center Historic District, a local historic district which comprises properties around the Town Common, on East Main St. and the south side of Main St. The

Hopkinton, Massachusetts

district was expanded in 2000 to include the Town Hall and in 2001 to include Center School. The Hopkinton Supply Company Building on Main St., located slightly west of the district, is listed in the National Register of Historic Places. Former factory worker housing in the center of town, contrasted against the more rural areas surrounding it, are visual reminders of Hopkinton's past. In 2005 the town established a second historic district in the village of Woodville. Ninety-seven properties are included within this district. The village of Woodville has retained its distinctive village atmosphere and strong architectural connection

Hopkinton, Massachusetts

to Hopkinton's industrial development and growth from the mid-to-late 19th century. The area was an early cotton clothmaking center and the site of a major shoe factory. When Boston seized Lake Whitehall for its water supply in 1894, the factories along its shores were closed or moved to other sites, as they were considered sources of pollution. Remaining factories and other buildings were destroyed in a fire in 1909. In the 18th century, it was an agricultural area with a few farms scattered north of the much smaller Lake Whitehall and its accompanying cedar swamp, and was

Hopkinton, Massachusetts

the site of a grist mill on Whitehall Brook as early as 1714. Within or near the Miscoe-Warren-Whitehall Watersheds ACEC (Area of Critical Environmental Concern), remains of large pits have been found. The pits were lined with bark by the Native Americans and used to store corn over the winter months. At one time, it was believed that the waters flowing from the large swamp south of Pond St., under Pond St. and into Lake Whitehall contained magical healing powers. As a result, the area quickly was built up as a resort area. Visitors came by stagecoach to

Hopkinton, Massachusetts

the Hopkinton Hotel, which was located between Pond St. and the lake. The mineral baths and their powers lured the visitors to the area. The baths can still be viewed by the edge of the stream that drains from the swamp. Within the ACEC area are also two beehive shaped stone structures, about tall. Their origin and use are unknown. Hopkinton gains national attention once a year in April as it hosts the start of the Boston Marathon, a role the town has enjoyed since 1924. The town takes pride in its hospitality as runners from all over the world

Hopkinton, Massachusetts

gather in Hopkinton to begin the run to Boston. It is also a sister city of Marathon, Greece. Geography. According to the United States Census Bureau, the town has a total area of , of which is land and , or 5.82%, is water. Hopkinton is east of Worcester, west of Boston, and from New York City. According to the United States Census Bureau, the census-designated place for the village has a total area of , of which is land and 0.22% is water. Adjacent towns. Hopkinton is located in eastern Massachusetts, bordered by six towns: Climate. The climate in Hopkinton tends

Hopkinton, Massachusetts

to be hot and humid during the summer, with daily high temperatures averaging in the 80s. Temperatures in the 90s are also known to occur between June and August as high-pressure air masses push in from the south. Winters are typical of areas inland and west of Boston. Snowfall averages around 45" but can vary tremendously from season to season. The warmest month of the year is July with an average minimum and maximum temperature of and respectively. The coldest month of the year is January with an average minimum and maximum temperature of respectively. Temperature variations between night

Hopkinton, Massachusetts

and day tend to be fairly limited during summer with a difference that can reach , and fairly limited during winter with an average difference of . The annual average precipitation at Hopkinton is . Rainfall is fairly evenly distributed throughout the year. The wettest month of the year is November with an average rainfall of . Demographics. Between the 2010 census and 2020 census, Hopkinton was the fastest-growing community in Greater Boston. As of the census of 2010, there were 14,925 people, 4,957 households, and 3,978 families residing in the town. The population density was . There were 5,128 housing units at an

Hopkinton, Massachusetts

average density of . The racial makeup of the town was 93.1% White, 0.8% Black or African American, 0.1% Native American, 4.4% Asian, 0.4% from other races, and 1.2% from two or more races. Hispanic or Latino of any race were 1.8% of the population. There were 4,957 households, out of which 48.1% had children under the age of 18 living with them, 70.5% were married couples living together, 6.9% had a female householder with no husband present, and 19.7% were non-families. 16.0% of all households were made up of individuals, and 5.6% had someone living alone who was 65

Hopkinton, Massachusetts

years of age or older. The average household size was 2.99 and the average family size was 3.38. Population was well-distributed by age, with 33.6% under the age of 20, 3.4% from 20 to 24, 22.0% from 25 to 44, 33.0% from 45 to 64, and 7.9% who were 65 years of age or older. The median age was 40.3 years. For every 100 females, there were 96.8 males. For every 100 females age 18 and over, there were 93.4 males. As of 2000, the median income for a household in the town was $89,281, and the median

Hopkinton, Massachusetts

income for a family was $102,550. Males had a median income of $71,207 versus $42,360 for females. The per capita income for the town was $41,469. About 1.3% of families and 1.7% of the population were below the poverty line, including 1.4% of those under age 18 and 3.4% of those age 65 or over. Hopkinton village. As of the census of 2000, there were 2,628 people, 1,003 households, and 672 families residing in the CDP. The population density was 611.3/km (1,584.3/mi). There were 1,024 housing units at an average density of 238.2/km

Hopkinton, Massachusetts

(617.3/mi). The racial makeup of the CDP was 97.14% White, 0.38% Black or African American, 0.15% Native American, 0.91% Asian, 0.08% Pacific Islander, 0.68% from other races, and 0.65% from two or more races. Hispanic or Latino of any race were 2.05% of the population. There were 1,003 households, out of which 34.5% had children under the age of 18 living with them, 55.4% were married couples living together, 9.2% had a female householder with no husband present, and 33.0% were non-families. 28.9% of all households were made up of individuals, and 14.5% had someone living alone who

Hopkinton, Massachusetts

was 65 years of age or older. The average household size was 2.52 and the average family size was 3.17. In the CDP the population was spread out, with 26.5% under the age of 18, 4.3% from 18 to 24, 32.0% from 25 to 44, 20.5% from 45 to 64, and 16.7% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 85.7 males. For every 100 females age 18 and over, there were 82.3 males. The median income for a household in the CDP was $52,250, and the

Hopkinton, Massachusetts

median income for a family was $68,050. Males had a median income of $48,050 versus $37,862 for females. The per capita income for the CDP was $23,878. About 2.9% of families and 3.3% of the population were below the poverty line, including 5.1% of those under age 18 and 4.0% of those age 65 or over. Government. Since its incorporation in 1715, Hopkinton has retained its original Open Town Meeting form of government. The town's day-to-day affairs had been directly overseen by an elected Board of Selectmen until 2007, when the Town's

Hopkinton, Massachusetts

Charter Commission created a Town Manager position with more discretion, although the Town Manager still reports to the Selectmen. Town Meeting. Begins on the first Monday in May and continues on consecutive evenings until the entire warrant is voted on. Warrant. The Town Meeting Warrant is a document composed of the articles to be voted on. Any elected or appointed board, committee, or town officer or ten petitioning voters may request that an article be included on the warrant. Each article to be voted on is directed by the Board of Selectmen to an appropriate board or committee to hear

Hopkinton, Massachusetts

and provide the original motion at Town Meeting. All articles which require expending of funds are directed to the Finance Committee; articles dealing with planning and zoning to the Planning Board; articles relating to by-laws to the By-Law Committee, and so forth. Annual town election. Held on the third Monday in May. Polls are open 7:00am–8:00pm. All Hopkinton precincts vote at the Hopkinton Middle School (88 Hayden Rowe St). County government. Massachusetts has 14 counties which were regional administrative districts before the Revolutionary War. In 1997, the county governments of Middlesex, Berkshire, Essex, Hampden and Worcester were abolished

Hopkinton, Massachusetts

. Many of their functions were turned over to state agencies. Its county seats are Cambridge and Lowell. Library. The Hopkinton Public Library was founded in 1867. It has been located in the heart of downtown, just steps away from the Town Common, since 1895. Until 1955, bequests were the only source of funding for the library. Since that time, the town government has been appropriating public funds for employee salaries, cost of cleaning the Library, utilities and assistance with the purchase of books. The library is now funded through various sources that include the Town Government, The McGovern Trust Fund

Hopkinton, Massachusetts

, Annual State Aid and Friends of the Library. The town library was established by the Young Men's Christian Association in 1867. Seven members served as the Trustees, incorporated the Library and adopted by-laws for the government of the Library in 1890. The current building was built in 1895 with contributions from local and former residents of Hopkinton. The second floor was used as a lecture hall and was remodeled later as a children's room. A gallery was built to connect the Library building with the adjacent Episcopal Church after extensive renovation in 1967. This new section was

Hopkinton, Massachusetts

named after the head librarian at the time, Mrs. Betty Strong. A special feature of the reading room is a stained glass window with a motif of water fountain bubbling water flowing over an open book and the inscription on the page reads "The fountain of wisdom flows through books." The large hall clock that still stands near the circulation desk was presented to the Library by Mrs. F.V. Thompson and Mr. Abram Crooks. The library was transferred to the town government in May 2010. Five members were appointed as the Library Trustees. Starting from May 2011, elections have been

Hopkinton, Massachusetts

held annually for the members of the Library Board according to the new town charter. In January 2016, the library announced they would make renovations to the building and moved to a temporary location at 65 South Street while the historic building on Main Street undergoes a major renovation and expansion. In October 2017, the renovated and expanded library reopened in its downtown location at 13 Main Street. Education. Public schools. The Town of Hopkinton has a public school system which serves students from pre-kindergarten through twelfth grade. The Hopkinton Public Schools maintains a district website with a subpage

Hopkinton, Massachusetts

for each Hopkinton school. Kindergarten students and first-graders attend Marathon Elementary School. Grades 2 and 3 attend Elmwood School. Grades 4 and 5 attend Hopkins School. Grades 6 through 8 attend Hopkinton Middle School. Grades 9 through 12 attend Hopkinton High School. The town also has an integrated preschool currently located in the Marathon Elementary School building. Hopkinton offered a fee-based full-day kindergarten option for the first time during the 2010–2011 school year via a lottery system. Free full-day Kindergarten was made available to all Kindergarten students starting in the 2014–2015 school year. Hopkinton Public Schools

Hopkinton, Massachusetts

does not offer any foreign language education before Grade 7. Since residents approved the Center School Feasibility Study in May 2008, Hopkinton had been involved in an Elementary School Building Project with the Massachusetts School Building Authority. The solution approved unanimously by the Hopkinton Elementary School Building Committee and the MSBA was to build a new K–5 Elementary School on the town-owned Fruit Street property and then decommission the aging Center School. Residents voted down the new school at the March 21, 2011 Special Town Meeting and again at a Special Town Election on March 28, 2011. In May

Hopkinton, Massachusetts

2013 voters approved funding a new Center School Feasibility Study. The solution proposed by the new Elementary School Building Committee was to build a new Preschool, Kindergarten and Grade 1 School at 135 Hayden Rowe Street (Route 85), on property newly purchased by the town for this purpose. This proposal was approved by voters at a November 2015 Special Town Meeting. The new school, Marathon Elementary School, opened in fall 2018. It is located near the Hopkins School, Middle School and High School, on the same two-lane road, Route 85, which is the main north-south road in Hopkinton

Hopkinton, Massachusetts

. Hopkinton High's school mascot is the Hiller "H", as the sports teams are known as the Hopkinton Hillers. Previously the teams were known as the Hopkinton Stonethrowers. The school primary colors are green and white, with orange as a secondary color. Economy and business. Hopkinton is the corporate headquarters of Dell EMC, a global manufacturer of software and systems for information management and storage. Dell EMC, in addition to providing $1 million in annual real estate tax revenues, is a major contributor to the town's schools and recreational services. On September 7, 2016, Dell and EMC merged

Hopkinton, Massachusetts

, creating Dell EMC. Transportation. Hopkinton is situated west of Boston in the MetroWest region of Massachusetts. Interstate Route 495 divides the town into east and west zones, which are connected by numerous spokes providing direct access to the airport and other communities in the Greater Boston Metropolitan Area. Major highways. Hopkinton is served by two interstate highways and two state highways. Interstates 90 (the Massachusetts Turnpike) and 495, form an interchange on the northern border of Hopkinton and neighboring Westborough. Proximity to Route 9 (The Boston/Worcester Turnpike) and Route 30 in Westborough, gives additional access to east/west destinations

Hopkinton, Massachusetts

. Principal highways are: Mass transit. Rail. There is no passenger or freight rail service in Hopkinton. Hopkinton is served by the Southborough MBTA Station, located on the border of Hopkinton and Southborough on Route 85 at Southville Road. MBTA commuter rail service is available to South Station and Back Bay Station, Boston, via the MBTA Framingham-Worcester Commuter Rail Line which connects South Station in Boston and Union Station in Worcester. Travel time to Back Bay is about 50 minutes. Originally called the Framingham Commuter Rail Line, Framingham was the end of the line until rail traffic was expanded to

Hopkinton, Massachusetts

Worcester in 1996. The line also serves the communities of Newton, Wellesley, Natick, Ashland, Southborough, Westborough and Grafton. Direct rail service to Boston, to New York, and to many other points on the Amtrak network (National Railroad Passenger Corporation) is available through nearby Framingham. CSX Transportation provides freight rail service and operates an auto transloading facility in nearby Framingham. Air. Boston's Logan International Airport is easily accessible from nearby Framingham. MassPort provides public transportation to all airport terminals from Framingham via the Logan Express bus service seven days per week. The bus terminal and paid parking facility are located

Hopkinton, Massachusetts

on the Shoppers' World Mall property, off the Massachusetts Turnpike Exit 13, between Route 9 and Route 30, at the intersections of East Road and the Burr Street connector. Worcester Regional Airport, a Primary Commercial (PR) facility with scheduled passenger service, is easily accessible. It has two asphalt runways long. Instrument approaches available include precision and non-precision. JetBlue, American Eagle, and Delta all fly into Worcester. Commuter services. Park and ride services: Media. Newspapers. Hopkinton has two local newspapers: "The Hopkinton Independent" and "The Hopkinton Crier", and three online news outlets, HCAM, Hopkinton Patch and HopNews. The town is

Hopkinton, Massachusetts

also served by "The Boston Globe", "The MetroWest Daily News", and the "Telegram & Gazette". Television. Hopkinton has a PEG television network known as HCAM, which controls two channels. Many HCAM shows can be viewed directly on their website. HCAM-TV. HCAM-TV is the most-received of HCAM's channels, available in every household with cable television in the area. It can be found on Comcast channel 8 and Verizon channel 30. The channel's daily schedule consists mostly of programming aimed at a family audience. Along with series and informative programming, HCAM-TV broadcasts the filming of one-time

Hopkinton, Massachusetts

events (such as performances on the Hopkinton Common and films by the Hopkinton Center for the Arts). HCAM-ED. HCAM-ED, sister channel to HCAM-TV, is received by fewer households and has lower programming standards than HCAM-TV. It is found on Comcast channel 96 and Verizon channel 31. The HCAM website also includes news articles and photos, updated daily. Historic homes. Historical commission. The Town of Hopkinton established a historical commission which manages "the preservation, protection and development of the historical or archeological assets of such city or town". Projects include conducting research for places of historic or

Hopkinton, Massachusetts

archeological value, assisting cooperatively with others engaged in such research, and carrying out other initiatives for the purpose of protecting and preserving such places. National Register of Historic Places. Hopkinton has two properties in the register. Hopkinton, Massachusetts Hopkinton is a town in Middlesex County, Massachusetts, United States, less than west of Boston. The town is best known as the starting point of the Boston Marathon, held annually on Patriots' Day in April, and as the headquarters for the enterprise-oriented Dell EMC. At the 2020 census, the town had a population of 18,758. The U.S. Census recognizes a village

Hopkinton, Massachusetts

Li River Li River The Li River or Li Jiang () is the name for the upper reaches of the Gui River in northwestern Guangxi, China. It is part of the Xijiang River system in the Pearl River Basin. The river flows from Xing'an County to Pingle County, where the karst mountains and river sights highlight the famous Li River cruise. Background. The Li River originates in the Mao'er Mountains in Xing'an County and flows in the general southern direction through Guilin, Yangshuo and Pingle. In Pingle the Li River merges with the Lipu River and the Gongcheng River and continues south as

Li River

the Gui River, which falls into the Xi Jiang, the western tributary of the Pearl River, in Wuzhou. The upper course of the Li River is connected by the ancient Lingqu Canal with the Xiang River, which flows north into the Yangtze; this in the past made the Li and Gui rivers part of a highly important waterway connecting the Yangtze Valley with the Pearl River Delta. The course of the Li and Gui Rivers is flanked by green hills. Cormorant fishing is often associated with the Lijiang (see bird intelligence). Li River cruises from Guilin to Yangshuo are famous

Li River

, attracting millions of visitors a year. Geology. The Li River and tributaries drain the area from Guilin to Yangshuo, descending from 141 m at Guilin to 103 m at Yangshuo. Mean flow past Guilin is 215 cubic metre per second, and alluvium sediments consisting of well sorted gravels covered by silty sand, form floodplains and terraces along its route. Yet, it is the 2,600 m of Devonian and Carboniferous limestones and karst terrain within the Guilin Basin, that gives the area a dramatic landscape. Two distinctive types of karst are found, Fengcong, and Fenglin, which have evolved for the past

Li River

10-20 million years, within the Cenozoic. Fengcong karst dominates the course of the Li River and is defined as a group of limestone hills with a common limestone base, with deep depressions or dolines between the peaks, and sometime described as peak cluster depression karst. Hundreds of caves are present in this terrain, with 23 having passages longer than -1 km alongside the Li River gorge. The longest is the Guanyan Cave System that extends from Caoping to Nanxu. Fenglin dominates the area around Yangshuo and south of Guilin and is defined as isolated limestone hills separated by a

Li River