The Structure Of Skeletal Muscle Biology Essay

The Structure Of Skeletal Muscle Biology Essay Skeletal Muscle is a form of fibrous tissue with the fibers arranged parallel to each other. A muscle fiber (cell) is surrounded by the endomysium. A group of these cells is wrapped by fascicles. Bundles of fascicles are covered by the perimysium and bundles of the perimysium are wrapped by the epimysium to form a muscle. The muscle fibers have contractile properties which enable them to move bony levers in order to produce skeletal movement1. The functional unit of the muscle fiber is the sacomere which consists of most importantly, actin and myosin. The actin and myosin are arranged such that during contraction, they can slide over each other thus shortening the muscle2. Muscles suffer from many diseases, one of which is polymyositis. This is an inflammatory myopathy that affects mainly the muscles of the thorax and those around the torso. It affects all age groups but has been noticed mainly in late childhood and early adulthood. The sypmtomps are nonspecific but results in general muscle weakness and the cause, though believed to be an invasion by the white blood cells, is not very clear10. 2.0 The Structure of Skeletal Muscle. In daily life, structures and arrangements of designs are dictated, to a large extent by the purpose and function for which the design is meant for. Knowing that skeletal muscle is made up mainly of fibrous tissues, the arrangement of these tissues and how they are bound together to maintain a particular shape in order to accomplish different purposes (mainly to generate force and produce movement) may to a large extent, define the structure of the muscle4. At a macro level, the skeletal muscle is composed of bundles of individual muscle fibers, the supporting structure called the basal lamina, and the connective tissue sheaths as shown in figure 1. These connective tissues bind the cells together giving them strength and partly providing mechanical protection2. We can examine these connective tissues and their functions as follows: 2.1 The basal lamina. This is an extracellular matrix that acts as a scaffold on which a cell sits. It has been realized that apart from providing structural support, the basal lamina can orient and constrain cell during the process of regeneartion3. 2.2 The endomysium. This is a fine sheath of connective tissue that surrounds each individual muscle cell. The endomysium consist of loosely interlacing fibers composed mainly of collagen4. 2.3 The perimysium and fascilces. The individual muscle fibers wrapped by the endomysium, are grouped together in what is called fascicles. A layer of fibrous tissue called the perimysium wraps each fascicle4. 2.4 The epimysium. This is the outside layer that finally wraps the whole muscle. It is composed of dense irregular connective tissue4. Figure 1 Source: http://www.web-books.com/eLibrary/Medicine/Physiology/Muscular/muscle_structure.jpg 3.0 The muscle cell Having described how individual muscle cells are organized into a muscle, it is imperative that we look at the structural composition of the cell itself. Just like many other cells in the body are specialized according to their functions, skeletal muscle cells are specialized to produce force and movement5. The skeletal muscle fiber is thus composed of mainly three structural elements:-the myofibrils, the sarcoplasmic reticulum and the mitochondria, each contributing a unique aspect of muscle function. The entire function of the muscle can be attributed to the shifts in proportions of these three structures6. 3.1 The Myofibrills. These are cylindrical specialized sub-units within the muscle fiber. They consist of two types of contractile protein filaments-the thin filaments referred to as actin and the thick filaments referred to as myosin. The two most important parameters of the myofibrils are their diameter which determines its strength and the fiber length which determines it contraction velocity and distance over which the fiber can contract. The myofibril consist of two filaments-actin and myosin6,2. 3.1.1 Actin (thin filament). Actin filaments are responsible for regulation of contraction. The actin filament is formed by a helical arranged of actin monomers which is an ambiguous protein2 (figure 2). Because of the helical nature, a long grove is formed along the filament and the protein troponin is located at intervals along the length of the actin filament. It is troponin which is responsible for turning on contraction2,7. Figure 2.The actin molecule. Source: http://www.ucl.ac.uk/~sjjgsca/Muscleslidingfilament1.gif 3.1.2 The Myosin (thick filament). Myosin filament is about 150nm long. It has a tail and two heads. The tail is formed by two helical shaped fibers that coil around each other. A collection of several of these helical tails together form a myosin filament (figure 3)4b. Figure 3. The myosin molecule. Source: http://webanatomy.net/anatomy/myosin.jpg. 3.2 The sarcoplasmic reticulum (SR). Groups of about 200 thick and thin filaments constitute a myofibril. Each myofibril is thus enclosed in a membrane called the sarcoplasmic reticulum8. The SR membrane stores and releases calcium during muscle contraction and relaxation. The SR can therefore be thought of as the functional unit of the myofibril9. 3.3 The mitochondria. Found within the cell cytoplasm, the mitochondria are responsible for generation of most of the cells energy by the production of adenosine triphosphate (ATP). There are several mitochondria distributed along the length of a myofibril4. 4.0 The mechanism of muscle contraction Muscle contraction can largely be attributed to the structure of actin and myosin, their arrangement within the SR and the interaction between them in order to produce force (Figure 4). This type of arrangement allows the thin actin filaments to slide in and out by the action pull of the myosin heads8b. Figure 4. Actin and myosin arrangement: Source: http://www.exrx.net/Images/ActinMyosin.gif Muscles are composed of a number of actin and myosin filaments arranged in series in a basic unit called the sacomere. The sacomere consists of a thick filament in the meddle and two thin filaments, one overlapping on each side. The heads of the thick filament attach to the thin filament at the overlap and these heads allow movement in only one direction. When activated, each thick filament head rachets repeatedly along the actin, pulling the two actins closer together. Since the actin are attached to the Z line (The distance between two Z lines form the sacomere), ends of the sacomere (Z lines) are pulled in and the sacomere shortens. The sacomeres are arranged in series so that when the muscle fiber contracts, all the sacomeres contract simultaneously transmitting the force to the end of the muscle. The whole process of contraction described above occurs when the muscle is electrically stimulated2b. 5.0 Muscle stimulation. Skeletal muscle cells are stimulated by the motor neurons of the somatic nervous system. The reception of the motor stimulus (action potential) opens the calcium channels allowing calcium which is stored in the SR to be released. The release of calcium causes the release of acetylcholine-Ach (neurotransmitter). The calcium binds to the troponin on the actin filament. Troponin then regulates the tropomyosin which obstructs binding sites for myosin. This allows the tropomyosin to move, unblocking the bonding site. Myosin then binds to the unblocked site on the actin and applies a pull. This will pull the Z bands towards each other thus shortening the sacomere, causing muscle contraction2b. However, as calcium is released, the ATP-dependent calcium pump is activated and it continuously pumps calcium back to the SR to be stored again. This leads to a drop in calcium level within the cytoplasm. When the calcium level is too low, the calcium binding action to troponin is terminated, releasing tropomyosin which again blocks the binding site. This stops the interaction between actin and myosin thus relaxing the muscle2b. 6.0 Muscle Diseases There are a number of muscular diseases and disorders ranging from acquired, familial to congenital. Limiting ourselves to one of the acquired disorders of the muscles, lets look at polymyositis. 6.1 Polymyositis (PM). PM is a type of muscle inflammatory myopathy. Just like the name suggests, this disease causes inflammation of the muscle fiber. Although the causes of the disease are not well understood, it is believed that PM begins when white blood cells, spontaneously invade muscles. This can result in severe muscle weakness. Polymyositis is a persistent disease characterized by periods of increased and reduced or no symptoms. PM affects mainly the muscles of the thorax and is more common in women than men. It is said to affect all age groups although is it commonly noted in early childhood or 20s10. Key pathologic and diagnostic features of the disease. Endomysial inflammation. This is the inflammation of the outer connective tissue that surrounds the muscle fiber. This is done by the white blood cells that leave the blood and enter the tissue, somehow confirming the earlier assertion that the PM begins when white blood cells invade muscles. Invasion of myofibers by autoaggressive lymphocytes. This is when the T lymphocytes begin to attack the intact myofibers. Unlike in muscle dystrophy where inflammation is associated with degenerating myofibers, the invasion of T lymphocytes causes inflammation of health myofibers in PM.This causes inflammation of healthy myofibers. Other diagnostic features that may not be exactly specific to PM include myofiber necrosis, myophagocytosis, myofiber atrophy and fibrosis, a feature of chronic PM10,11. 7.0 Conclusion Human movement is only possible because of the action of muscle contraction. Voluntary contraction of muscle is made possible by the somatic nervous system which sends out an action potential activating the contraction process. The process is accomplished by the sliding of myosin and actin over each other. Many diseases and disorders affect muscles, prominent among them is muscular polymyosis which causes inflammation of the muscles mainly around the torso. Its believed to be caused by the unwanted action of the white blood cells and the symptoms include muscle weakness.

Malunggay Essay

Theoretical Framework The following theories provide framework of this research. This study was anchored on the Theory of Kramer (1995). â€Å"The Texture Measurements of Foods: Psychological Fundamental, Sensory, Mechanical, and Chemical Procedures, and their Interrelationships (1995),† that sensory quality of foods, being a psycho-physical phenomenon, should be systemized or classified accordance with the sense by which the various attributes of quality are perceived by the consumer. The following attributes are used to determine and measure the quality of a product: appearance, taste, texture and aroma. As positioned by the author appearance includes factors such as size, shape, color, and external attributes such as the attractiveness of the icon or logo. Size and shapes are measurements often used as grade standards or to differentiate between items. The assessment of size and shape is often a subjective process although, for many products, visual guide have been developed. Color is the primary indicatory of maturity is the result of the type and quan tity of pigments in the product. Changes in color are often related to freshness or deterioration of the product. Color can be measured by many visual or mechanical methods. On the other hand, taste is the perception of chemical compounds on the tongue and other nerve endings of the mouth. The basic tastes are sweet, sour, bitter, and astringent. Sweetness is directly related to sugars into the food and the sugar to acid ratio. Sourness is the result of the organic acids present. Compounds such as those in citrus fruits or coffee usually impart bitterness, where astringency is often the result of tannins such as the phenolic compounds in grapes (Kramer, 1995). Also, texture is â€Å"the composite of those properties which arise from the structural elements of a product, and the manner in which this composite registrars with the physiological sense† (Szczesniak, 2005). Most textural characteristics, except firmness are evaluated as mouth feels, i.e. the impression on the tongue, palate and teeth. In production , common textural characteristics include tenderness, crispiness, crunchiness, chewiness, and fibrousness. Texture is generally determined by measuring force applied to the food. Lastly, aroma is the sum of the compounds perceived by the nose. It is very difficult to determine objectively since it is a combination of qualitative predominant and quantitative traits in a food product. Fruits and vegetables are rich in  aromatic compounds; many of which are yet to be identified. Thus, in identifying the quality of the ordinary meat burger patties and the quality of the new product innovation which is the malunggay burger patty, the researchers used Kramer’s classification of quality to collect the raw data from the respondents. Another theory to support this study is the â€Å"Diffusion of Innovations Theory† by Thurber and Fahey (2009). This theory is used to describe well the evidence for growth and adoption of dietary Malunggay or Moringa oleifera and it highlights the need for a scientific consensus on the nutritional benefits. Diffusion is the process by which an innovat ion is communicated through curtain channels over time among the members of a social system. According to Thurber and Fahey (2009), the rate of adoption and possibilities of over adoption can be predicted using five characteristics of a new innovation. In order for Moringa oleifera to be adopted and for its wide spread use to be promoted, evidence must be provided for the following attributes: The first attribute is called Relative Advantage which is the extent to which an innovation is perceived as being better or more useful than the idea it supersedes. Then, it is followed by the Compatibility which means the measure of how well an innovation is consistent with existing social and cultural practices, if it is likeable, and whether it meets the need of potential adopters. On the other hand Complexity is the level to which the innovation is perceived to be difficult to understand or use. Another attribute is Observability which is used to describe how well the results of the innovation can be seen and communicated to others. And finally, Trialability which refers to the ability of an innovation to be experimented with. The Diffusion of Innovations Theory is used to determine the rate of adaptation of the Malunggay or Moringa oleifera. Using this theory, it will give accurate knowledge on the effectiveness and health benefits of Malunggay or Moringa oleifera shall be known. Conceptual Framework The conceptual framework of this research shall focus on the independent variables such as the respondent’s age, gender and grade level. Likewise, the dependent variables of the study are the respondent’s evaluation regarding the product in terms of appearance, taste, texture and aroma. Once these dimensions are known, a proposed Food Feeding Program shall be formulated.

My Name Is Jack And I Am Known As A Freak - 1796 Words

My name is Jack and I am known as a freak. I don’t know how or when I have come to accept this but nevertheless it is true. I live in a small shack deep within the forest with my adopted father and 2 older siblings. As I would believe not only I but the rest of my family would be labeled as freaks as well but unlike me they never cared about their labels so why did I. As my thought process began to move faster I heard a knock on my door. â€Å"Jack, are you alright? We haven’t seen you in a while.† I looked at my bedroom do for while then responded. â€Å"I’m fine father, just thinking about some things. Alright,† I heard him say,† come out when you’re ready. I’ll be out doing my runs for today.† I then heard him walk off and the front door closing. I stared at the ceiling for a second then walked in front of bedroom mirror. When I looked through I saw a monster. The monster was wearing black gloves and hoodie covering his head and brown hair. Along with this it was wearing a light blue mask with dried black ooze going down the eyelids. I looked at the monster then cringed in anger and fear and punched the mirror shattering it into pieces. As the mirror pieces hit the ground I stared at my fist and frowned under my mask. As I walked out of my room I saw my older brother Jeff laughing towards my older sister Jane while playing with his knife. He noticed me and grinned. Jeff was like me, a freak of nature. He always wore a white sweatshirt covered in theShow MoreRelatedMuch Ado About Nothing by William Shakespeare as a Satire Essay1103 Words   |  5 Pagesof the wars won, and the bravery of certain soldiers. The mood in this opening dialogue would be deadly serious if it wasnt for Beatrice making a mockery of the brave and valorous Signor Mountanto. How many hath he killed? For I promise to eat all of his killing. She claims here that Benedick doesnt actually have the stomach to kill anybody, and retorts to every sincere statement with a wry satirical comment about Benedicks courage. This sort of language is Read MoreSt. John s Wort Essay11098 Words   |  45 Pagesstores. Requiring a warm and moist climate, the plant had previously been known only around the South Pacific islands - particularly, New Guinea, New Zealand, and Hawaii. There it was renowned for promoting, in those who imbibed it, feelings of relaxation and contentment - and, in large doses, of intoxication. Many old native practices for the preparation of Kava involved chewing bits of the root (where its active ingredients, known as kavalactones, chiefly reside) and spitting them out into a great bowlRead MoreLimitation of Trait Theory12233 Words   |  49 Pagescontingency or situational approach (1960s and 1970s). TRAIT APPROACH. The scientific study of leadership began with a focus on the traits of effective leaders. The basic premise behind trait theory was that effective leaders are born, not made, thus the name sometimes applied to early versions of this idea, the great man theory. Many leadership studies based on this theoretical framework were conducted in the 1930s, 1940s, and 1950s. Leader trait research examined the physical, mental, and social characteristicsRead MoreEssay on Fall of Asclepius95354 Words   |  382 PagesFall of Asclepius By Harm 1 and Icrick Prologue Where should I begin? The apocalypse happened so fast. In less than a month, monsters infested every part of this world. People panicked, people died. They clawed at each other just to get out of all the infested areas around the world. There was problem about fleeing from infested areas. Everywhere was infested. There was no where anyone could go without encountering the walking plague. You know that phrase War is Hell? Well... its deadRead MoreLady Gaga case study11446 Words   |  46 Pagesfor instance, covered the flagship label Interscope Geffen AM as well as The Island Def Jam Music Group and Universal Motown Republic Group, among others. Led by famed music producer Jimmy Iovine, Interscope’s roster included some of the biggest names in music, such as Eminem, Mary J. Blige, the Pussycat Dolls, The Black Eyed Peas, Timbaland, and U2. Collectively, the four major record companies accounted for more than 90% of the U.S. recorded-music market; smaller, independent (â€Å"indie†) labelsRead MoreConstraints and Challenges for the Global Manager13619 Words   |  55 PagesManager Dana Robbins-Murray Account Director Caliber Group Tucson, AZ MY JOB: You’ll be hearing more from this real manager throughout the chapter. I am an account director for Caliber Group, a full-service marketing/PR firm. My main responsibility is to work with our clients to determine what type of marketing or public relations they need to create better brand awareness and increase sales for their business. BEST PART OF MY JOB: Working with a large, diverse group of businesses that each haveRead MoreStrategic Marketing Management337596 Words   |  1351 Pagesorganization’s marketing department, whereas the general thrust of the more recent literature on marketing theory is that marketing is increasingly being conceptualized as an organizational philosophy or ‘an approach to doing † 4 S T R AT E G I C M A R K E T I N G M A N A G E M E N T business’. This strategic as opposed to a functional approach to marketing is captured both by McDonald (1989, p. 8): are utilized to satisfy the needs of selected customer groups in order to achieve the objectivesRead MoreFundamentals of Hrm263904 Words   |  1056 Pagesbetter study smarter save money From multiple study paths, to self-assessment, to a wealth of interactive visual and audio resources, WileyPLUS gives you everything you need to personalize the teaching and learning experience.  » F i n d o u t h ow t o M A K E I T YO U R S  » www.wileyplus.com ALL THE HELP, RESOURCES, AND PERSONAL SUPPORT YOU AND YOUR STUDENTS NEED! 2-Minute Tutorials and all of the resources you your students need to get started www.wileyplus.com/firstday Student

Machiavelli Personal and Political Implications Essay...

Machiavelli: Personal and Political Implications And since it is Fortune that does everything, it is she who wishes us to leave her alone, to be quiet and not give her trouble, and wait until she allows us to act again; then you will do well to strive harder, to observe things more closely.... (67)* Letter to Francesco Vettori in Rome December 10, 1513. Machiavelli is praised for the political implications of his writing in The Prince. However, many do not see the personal implications of Machiavellis work, because the motivations for action are spoken in terms of political domination and the acquisition of power. There are underlying principles that speak of domination not only of cities and nations, but the domination of the†¦show more content†¦Machiavelli analogizes Fortune to a river, a contemplative force that directs its path through weakness where she knows that dikes and embankments are not constructed to hold her (159). Because of this nature, a person who wants to dominate the circumstances instead of being ruled by them must look to see where the river has gone and predict where it will go next. This requires ceaseless planning with little rest, because rest develops into weakness and laziness. Machiavelli states that men who are separated from the rest of those who have ruled in terms of greatness, never enjoye d the benefits of the time, but they enjoyed instead benefits of their strength and prudence; for time brings with it all things and it can bring with it the good as well as the bad and the bad as well as the good (85). Consequently, it does not matter what Fortune brings; what matters is that the receiver of this Fate is prepared for any possible scenario. Notably, the skill to diagnose the ills when they arise is not universal, and is given to only a few men. However, it requires more than just the rare skill of recognizing the path of Fortune. To be a truly notable ruler, or human being in general, one must go beyond recognizing and preparing a plan to actually taking action. This is the point at which Pope Julius II and Cesare Borgia are praised by Machiavelli. Pope Julius entered his rule at a time when the temporal powers of the Pope were littleShow MoreRelatedBooks That Continue To Thrive Centuries After Their Initial1578 Words   |  7 Pagescases, controversy. In the 15th century, Niccolo Machiavelli composed a political treatise that has persisted primarily due to the questionable morality and brutal practices it promotes. Readers have spent centuries wrestling with this small but powerful book, trying to discern Machiavelli’s purpose, as well as how his writing has influenced political leaders since its publication. With a political background during a time of unrest in Italy, Machiavelli wrote with expertise and knowledg e, having seenRead More The Powerful Truth of Machiavellis The Prince Essay1490 Words   |  6 Pageskingdom. Machiavelli saw the conventional thought of the time as a fantasy and only applicable in a utopian society. His work The Prince shatters all previous political thought by stating that a ruler must not only use the traditionally accepted means of maintaining power but also be able to use brute force, deceit and even cruelty as the situation requires. In the tumultuous political climate of renaissance Europe his theories were proven valid repeatedly.    Niccolo Machiavelli was bornRead MoreSocrates And Machiavelli1681 Words   |  7 Pagespolitics, making a comparison or evaluation of a political system in his persona technically impossible. To claim that Socrates would or would not be supportive of any political system might then seem irresponsible, a presumptuous analysis not fitting for an academic recognizing the false equivalence between Socrates’ philosophy and Machiavelli’s political ethics. The strategy to conduct any sort of liable and valid analysis is not to wholly ignore the â€Å"political† part of the system but to evaluate the ethicsRead More Machiavelli And Plato Essay1564 Words   |  7 Pages Niccolio Machiavelli (Born May 3rd, 1469 amp;#8211; 1527 Florence, Italy.) His writings have been the source of dispute amongst scholars due to the ambiguity of his analogy of the amp;#8216;Nature of Politics; and the implication of morality. The Prince, has been criticised due to itamp;#8217;s seemingly amoral political suggestiveness, however after further scrutiny of other works such as The Discourses, one can argue that it was Machiavelliamp;#8217;s intention to infact imply a positiveRead MoreHenry David Thoreau s Civil Disobedience And Machiavelli1360 Words   |  6 Pagessubject that is a title of his essay Civil Disobedience and Machiavelli, author of The Qualities of the Prince, notice a pattern of conformity in society. When a major voting decision is not supported by a majority, people will often wait rather than advertise and fruitfully support their cause. Believing that their cause can only succeed if the majority is supportive, they wait until their chance is best to propose change. Machiavelli takes note of this behavior and writes a â€Å"manifesto† for a would-beRead MoreEssay on Machiavelli’s The Prince and the Modern Executive1943 Words   |  8 Pagesscience (Pollock 43), is alone enough to warrant its classification as a Great Book. Its author, Niccolo Machiavelli, a contemporary of Copernicus, is generally accepted as an early contributor to the scientific revolution, because he looked at power and the nature of sovereignty through the eyes of a scientist, focused completely on the goal without regard for religion and morals and ethics. Machiavelli taught that the way princes actually do govern often differs substantially from than the way they oughtRead MoreIn General Terms, Democracy Is Characterized As A Government1504 Words   |  7 PagesIn general terms, democracy is characterized as a government in which citizens have the capabilities to exercise political autonomy to influence the affairs of the state. To be more precise, citizens are able to exercise direct control over the government—as in the case of pure democracies—or they are able to exercise indirect control—as in the case of representative democracies. Of course this general characterization is an oversimplification of what a democracy is and precisely how it functionsRead More Comparing The Prince and Measure for Measure Essay1759 Words   |  8 PagesMeasure for Measure, is immediately introduced in the first scene, with the Dukes declaration Of government the properties to unfold/ Would seem in me taffect speech and discourse. It is not until the third scene of act one, however, that this political discussion becomes specific and, ultimately, linked to the Machiavellian notion of statecraft. In this scene, which details the exchange between Vincentio and the Friar, we learn the reasons for the formers deputising of Angelo. Both of the DukesRead MoreVirtue and Prince4449 Words   |  18 Pagestraditional. [edit] A Princes Duty Concerning Military Matters (Chapter 14) Machiavelli believes that a princes main focus should be on perfecting the art of war. He believes that by taking this profession a ruler will be able to protect his kingdom. He claims that being disarmed makes you despised. He believes that the only way to ensure loyalty from ones soldiers is to understand military matters. The two activities Machiavelli recommends practicing to prepare for war are physical and mental. PhysicallyRead MoreModern Political Theory : Hobbes And Locke s Difference Essay1544 Words   |  7 Pages Modern Political Theory Hobbes’s and Locke’s Difference in Theories of State (#2) Ramon Roque Jr. Political Science 3341-01 Fall 2016 â€Æ' Modern Political Theory Hobbes’s and Locke’s Difference in Theories of State Thomas Hobbes and John Locke are among the greatest philosophers whose political thoughts have laid down the foundations of modern politics. It’s possible to offer explanation in various endeavors that affect the humans in the modern setting using various concepts and thoughts as presented