Types of Muscle Fibers

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The graphs below show the types of music albums purchased by people in Britain according to s3x and age. Write a report for a university lecturer describing the information shown below.You should write at least 150 words. You should spend about 20 minutes on this task. model answer: The three graphs provide an overview of the types of music people purchase in the UK. At first glance we see that classical music is far less popular than pop or rock music. While slightly more women than men buy pop music, the rock market is dominated by men with 30% buying rock, compared to 17% of women. From the first graph we see that interest in pop music is steady from age 16 to 44 with 20% of the population continuing to buy pop CDs after the age of 45. The interest in rock music reaches its peak among the 25 to 34 year olds, though it never sells as well as pop. Interest also drops off after the age of 35 with an even sharper fall from age 45 onwards, a pattern which is the opposite to the classical music graph. Types of Muscle Fibers Types of Muscle Fibers Bởi: OpenStaxCollege Two criteria to consider when classifying the types of muscle fibers are how fast some fibers contract relative to others, and how fibers produce ATP Using these criteria, there are three main types of skeletal muscle fibers Slow oxidative (SO) fibers contract relatively slowly and use aerobic respiration (oxygen and glucose) to produce ATP Fast oxidative (FO) fibers have fast contractions and primarily use aerobic respiration, but because they may switch to anaerobic respiration (glycolysis), can fatigue more quickly than SO fibers Lastly, fast glycolytic (FG) fibers have fast contractions and primarily use anaerobic glycolysis The FG fibers fatigue more quickly than the others Most skeletal muscles in a human contain(s) all three types, although in varying proportions The speed of contraction is dependent on how quickly myosin’s ATPase hydrolyzes ATP to produce cross-bridge action Fast fibers hydrolyze ATP approximately twice as quickly as slow fibers, resulting in much quicker cross-bridge cycling (which pulls the thin filaments toward the center of the sarcomeres at a faster rate) The primary metabolic pathway used by a muscle fiber determines whether the fiber is classified as oxidative or glycolytic If a fiber primarily produces ATP through aerobic pathways it is oxidative More ATP can be produced during each metabolic cycle, making the fiber more resistant to fatigue Glycolytic fibers primarily create ATP through anaerobic glycolysis, which produces less ATP per cycle As a result, glycolytic fibers fatigue at a quicker rate The oxidative fibers contain many more mitochondria than the glycolytic fibers, because aerobic metabolism, which uses oxygen (O2) in the metabolic pathway, occurs in the mitochondria The SO fibers possess a large number of mitochondria and are capable of contracting for longer periods because of the large amount of ATP they can produce, but they have a relatively small diameter and not produce a large amount of tension SO fibers are extensively supplied with blood capillaries to supply O2 from the red blood cells in the bloodstream The SO fibers also possess myoglobin, an O2-carrying molecule similar to O2-carrying hemoglobin in the red blood cells The myoglobin stores some of the needed O2 within the fibers themselves (and gives SO fibers their red color) All of these features allow SO fibers to produce large quantities of ATP, which can sustain muscle activity without fatiguing for long periods of time 1/4 Types of Muscle Fibers The fact that SO fibers can function for long periods without fatiguing makes them useful in maintaining posture, producing isometric contractions, stabilizing bones and joints, and making small movements that happen often but not require large amounts of energy They not produce high tension, and thus they are not used for powerful, fast movements that require high amounts of energy and rapid cross-bridge cycling FO fibers are sometimes called intermediate fibers because they possess characteristics that are intermediate between fast fibers and slow fibers They produce ATP relatively quickly, more quickly than SO fibers, and thus can produce relatively high amounts of tension They are oxidative because they produce ATP aerobically, possess high amounts of mitochondria, and not fatigue quickly However, FO fibers not possess significant myoglobin, giving them a lighter color than the red SO fibers FO fibers are used primarily for movements, such as walking, that require more energy than postural control but less energy than an explosive movement, such as sprinting FO fibers are useful for this type of movement because they produce more tension than SO fibers but they are more fatigue-resistant than FG fibers FG fibers primarily use anaerobic glycolysis as their ATP source They have a large diameter and possess high amounts of glycogen, which is used in glycolysis to generate ATP quickly to produce high levels of tension Because they not primarily use aerobic metabolism, they not possess substantial numbers of mitochondria or significant amounts of myoglobin and therefore have a white color FG fibers are used to produce rapid, forceful contractions to make quick, powerful movements These fibers fatigue quickly, permitting them to only be used for short periods Most muscles possess a mixture of each fiber type The predominant fiber type in a muscle is determined by the primary function of the muscle Chapter Review ATP provides the energy for muscle contraction The three mechanisms for ATP regeneration are creatine phosphate, anaerobic glycolysis, and aerobic metabolism Creatine phosphate provides about the first 15 seconds of ATP at the beginning of muscle contraction Anaerobic glycolysis produces small amounts of ATP in the absence of oxygen for a short period Aerobic metabolism utilizes oxygen to produce much more ATP, allowing a muscle to work for longer periods Muscle fatigue, which has ...9SERVICE TECH Vol.465 03-4 The previous session covered the changes in the environment surrounding the diesel engine and described the ECDsystem (ECD-V series) and the common-rail system. This session describes the types of systems in the ECD-V seriesand their system configurations. Although the injection pump has the same basic construction as the distribution type pump, the ECD-V3 includesthe parts listed below due to the adoption of electronic control.• Solenoid spill valve (SPV) . . . . . . . . . . . . . . . . An actuator that controls the injection volume• NE sensor (NE) . . . . . . . . . . . . . . . . . . . . . . . . A sensor that detects the cam position of the pump• Fuel temperature sensor (THF) . . . . . . . . . . . . A sensor that detects the temperature of the fuel• Correction resistor or ROM . . . . . . . . . . . . . . . A part that corrects the injection volume and injection timing• Timing control valve (TCV). . . . . . . . . . . . . . . . An actuator that controls the injection timing The V1 is the first of the ECD-V series, which appearedin 1982. The V3, a swirl-chamber type diesel injectionsystem, appeared in 1985. The V3, which adopted a solenoid spill valve to controlfuel injection, enabled the control of the injection volumeon a cylinder-by-cylinder basis. Depending on the type of final injection volumecorrection and the solenoid spill valve that are used,three types of ECD-V3 are available: ECD-V3, ECD-V3(ROM), and ECD-V3 direct-acting valve. The V4 direct-injection diesel fuel injection system forsmall trucks and SUVs appeared in 1998. The V4 system, which uses an inner cam pumping mechanism, enables high-pressure injection at 1,300 bars. The V5 direct-injection diesel fuel injection system for passenger vehicles appeared at about the same time. TheV5 system uses pilot injection to reduce the combustion noise of the engine.11Types of Systems in ECD-V Series1-1 ECD-V Series1-2 Injection Pump for ECD-V3 10SERVICE TECH Vol.465 03-4 The ECD-V4, which is based on the ECD-V3, is an electronically controlled distribution type pump that hasadopted a completely new construction. The combustion performance of the engine with the ECD-V4 has beenimproved (by atomizing the fuel into finer particles and optimizing the rise rate of the injection pressure), andproviding the injection volume and injection timing with a higher level of precision and freedom. With respect to themajor changes that have been made from the ECD-V3, an inner cam mechanism, a highly responsive solenoidspill valve and EDU, and a correction ROM have been adopted. The ECD-V5, which is based on the ECD-V3, is a distribution type, electronically controlled fuel injection pump thatoffers higher injection performance and functionality. It provides pilot injection to reduce the combustion noise of theengine.1-3 Injection Pump for ECD-V41-4 Injection Pump for ECD-V5 SERVICE TECH Vol.465 03-411 The configuration of the ECD-V series system can be broadly classified into the following three systems: Intakeair system, Fuel system, and Control system. Intake air system . .This system, which draws the air that is necessary for combustion, consists of the areasfrom the air cleaner to the intake manifold. Fuel system . . . . . .This system, which injects the fuel that is necessary for combustion into the Part I: Introduction1 RationaleMetaphor, based on the association of similarity, is one of the two basic types of semantic transference that have been an interest for many linguistic researchers. Galperin ( 1981: 139-40) states that the term ‘metaphor’ can be understood as the transference of some quality from one object to another. Metaphor is widely used to designate the process in which a word acquires a derivative meaning.In theory, there are at least three communicative functions that metaphor might serve (Ortony 1975). First, they might allow one to express that which is difficult or impossible to express if one is restricted to literal uses of language. Evidence for this "inexpressibility" claim would constitute encouraging support for the necessity-of-metaphors view. A second possible function of metaphors is that they may constitute a particularly compact means of communication. Although conscious experience is continuous in form, the linguistic system we use to talk about it is comprised of discrete elements (lexical items). Unlike more literal forms of language, metaphor may enable us to convey a great deal of information in a succinct manner by obviating the need to isolate the predicates to be expressed into their corresponding lexical representations. Finally, metaphors may help capture the vividness of phenomenal experience. If metaphors convey chunks of information rather than discrete units, they can paint a richer and more detailed picture of our subjective experience than might be expressed by literal language. This we call the "'vividness" claim.In this paper we are interested in the first and last of these possible functions. Thus, we need to examine a discourse domain for which a prima facie case can be made for supposing that literal language will often be inadequate and which lends itself to variations in vividness. There doubtless are many such domains. The one that we selected was that of internal states, in particular, emotional states. The literature on the linguistic expression of emotions suggests a relatively high incidence of figurative language use (Davitz 1969), providing pragmatic reasons An investigation into the role of metaphor in description of emotion in poetic discourse1 for believing that the context of (linguistic) emotional expression may be a profitable one within which to study metaphor production. Emotional states seemed well-suited because they tend to have an elusive, transient quality that is difficult to describe using literal language, although, of course, they can usually be labeled using literal language. Thus, while it might be easy for a person to label an emotional state as, for example, "fear," it is difficult to provide a literal description of the quality of some particular experience of fear. Furthermore, because emotions vary in intensity, one might expect differential levels of vividness.Our thesis is entitled “ An investigation into the role of metaphor in description of emotions in English poetic disscourse” and focused on William Shakespeares’ sonnets. The choice is based on two reasons. Firstly, recent research states Part A: IntroductionI. RationaleIn order to become competent in a foreign language, it is important for language learners not only to acquire new vocabularies and a new set of phonological and syntactic rules but also to learn what Wilson (1986) calls the rules of speaking: the patterns of sociolinguistic behavior of the target language. The rules of speaking involve us in knowing when and how it is suitable to open a conversation, what topics are appropriate to particular speech events, how speech acts are to be given and interpreted. In many cases, this interpretation goes beyond what the language learners might intend to convey and includes assessments such as “polite” and “impolite”. In Vietnam, as the economy grows and international business develops, English proficiency becomes a master tool for young people to get a job. They encounter foreigners in everyday settings where communication is necessary. In the modern society, the need for communication is increasing, especially in the process of globalization, when communication spreads beyond the boundary of a country. During the last decades, linguistic researchers have broadened their focus of their interests from the development of grammatical competence to other areas of target language development, such as discourse and pragmatic competence, common speech routines, for example, requests, apologies, complaints, compliments, refusals, and the like have been most frequently studied in cross-cultural and interlanguage pragmatics. According to Tsui (1994), there seems to be little empirical research that has been conducted in responses to questions. For a long time, question-response has been considered one of the most basic structures of conversation (Schegloff, 1974) but as Tsui (1994; p. 160) points out: “responses have been given little attention in the speech acts literature. Most of the acts characterized and listed in the various taxonomies are illocutionary acts which are often done by making the function of utterance in discourse, and as many responding acts do not have a corresponding responding performative verb, this kind of analysis inevitably neglects responses”A characterization of utterances (based on observation of real-life discourse) is not likely to neglect the importance of responses. Let’s consider an example illustrated by Tsui (1994)A: What’s the time?B: (a) Eleven (b) Time for coffee(c) I haven t got a watch, sorry’1 (d) How hold I know(e) Ask Jack(f) You know bloody well what time it is(g) Why do you ask?(h) What did you say?(i) What do you mean?Various possible responses from (a) to (i) shows us the complicated relationship between question and a proper answer. For the same question, the speaker A may be replied in different ways with different intentions by the addressee. Obviously, a response can be a proper answer, an indirect or implicit reply, an evasive answer, a refusal or denial, an outright lie or even a challenge to the speaker’s questioning act. Moreover, the question-answer exchange cannot always be a simple relationship in the actual communicative process. It is the addressee’s response that may establish, deepen and maintain the conversation, develop the intimacy among interlocutors, or interrupt the interactional process and even badly change the participants’ role, for example, from friends to enemies. There is no doubt that BioMed Central Page 1 of 5 (page number not for citation purposes) Journal of Orthopaedic Surgery and Research Open Access Technical Note Passive mechanical features of single fibers from human muscle biopsies – effects of storage Fredrik Einarsson* †1 , Eva Runesson †2 and Jan Fridén 3 Address: 1 Department of Orthopaedics, Sahlgrenska University Hospital, Göteborg, Sweden, 2 Lundberg Laboratory for Orthopaedic Research, Göteborg, Sweden and 3 Department of Hand Surgery, Sahlgrenska University Hospital, Göteborg, Sweden Email: Fredrik Einarsson* - fredrik.einarsson@vgregion.se; Eva Runesson - eva.runesson@orthop.gu.se; JanFridén-jan.friden@orthop.gu.se * Corresponding author †Equal contributors Abstract Background: The purpose of this study was to investigate the effect of storage of human muscle biopsies on passive mechanical properties. Methods: Stress-strain analysis accompanied by laser diffraction assisted sarcomere length measurement was performed on single muscle fibres from fresh samples and compared with single fibres from stored samples (-20°C, 4 weeks) with the same origin as the corresponding fresh sample. Basic morphological analysis, including cross sectional area (CSA) measurement, fibre diameter measurement, fibre occupancy calculation and overall morphology evaluation was done. Results: Statistical analysis of tangent values in stress-strain curves, corresponding to the elastic modulus of single muscle fibres, did not differ when comparing fresh and stored samples from the same type of muscle. Regardless of the preparation procedure, no significant differences were found, neither in fibre diameter nor the relation between muscle fibres and extra-cellular matrix measured under light microscopy. Conclusion: We conclude that muscle fibre structure and mechanics are relatively insensitive to the storage procedures used and that the different preparations are interchangeable without affecting passive mechanical properties. This provides a mobility of the method when harvesting muscle biopsies away from the laboratory. Background Experiments that may be considered as the foundation for changing clinical practice must rely on data and data anal- yses without obscuring methodological issues. Analysis of mechanical properties of human muscle tissue experi- ments are typically performed using fresh tissue. For prac- tical reasons biopsies are commonly stored for subsequent analysis and therefore any factors related to storage per se affecting mechanical properties and mor- phology need to be addressed. In a current laboratory set-up, we have chosen to test pas- sive mechanical features as part of characterisation of muscles. We use stress-strain measurements of both single fibres and bundles accompanied by measurements of sar- comere length by means of laser diffraction technique as described by Yea et al. [1]. Reports of effects of storage of human muscle biopsies are scarce. Frontera and Larsson [2] investigated human specimens, especially regarding possible variations in test results Published: 7 June 2008 Journal of Orthopaedic Surgery and Research 2008, 3:22 doi:10.1186/1749-799X-3-22 Received: 15 January 2008 Accepted: 7 June 2008 This article is available from: http://www.josr-online.com/content/3/1/22 © 2008 Einarsson et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0 ), which permits ... 2/4 Types of Muscle Fibers Review Questions Muscle fatigue is caused by buildup of ATP and lactic acid levels exhaustion of energy reserves and buildup of lactic acid levels buildup of ATP... none of the above D Critical Thinking Questions Why muscle cells use creatine phosphate instead of glycolysis to supply ATP for the first few seconds of muscle contraction? 3/4 Types of Muscle Fibers. .. anaerobic metabolism in the muscles of the marathon runner aerobic metabolism in the muscles of the sprinter glycolysis in the muscles of the marathon runner A What aspect of creatine phosphate allows