Background Context
Studies on muscle typing and its potential to differentiate were widely conducted throughout the last 50 years. It began with publications by Buller et al in 1960 which suggested evidence that the central nervous system controls muscle differentiation. This resulted from the inability of slow muscle differentiation in a cat limb after being operated from the spinal cord. They further postulated that the division and cross-unit of nerves of fast and slow muscles would move the motoneurones that was formerly innervating fast muscle to innervate slow muscle. They then applied this cross-innervation technique to investigate the possible effects in reverse contractile characteristics[1]. It has been documented that chronic electrical stimulation, muscle ablation, hindlimb suspension and hormone manipulation have been used to cause changes in metabolic enzymes, Ca2+ handling proteins , myosin isoforms and regulatory proteins of skeletal muscle and muscle fiber type and size. John Holloszy’s classic paper (1967) provides evidence on the malleability of rat muscles and the adaptation of their energy metabolism to chronic exercise training through simple physiological stimulus. This comes to the two classic papers on hand by Gollnick et al in 1972 and 1973, where they address the idea of fibre type plasticity in human skeletal muscle by using fiber typing and needle biopsy of muscle. The initial interest stemmed from the early work of Reggie Edgerton et al, which provided critical data on the development of fiber type classification systems. Furthermore, Edgerton’s investigation introduced other researchers to the idea of exercise-induced fiber type transformation in rodent muscle.[2] This lead Gollnick and his colle...
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...ghest in type I muscle fibers, average in type IIa and lowest in type IIb. It was also observed that there was significant difference between groups, where lipid content was ~25-50% higher in muscle from type 2 diabetes and obesity than normal subject, Lipid content intensity in muscle was ~40-50% higher in obese and type 2 diabetes than normal subjects.
In Figure 3A, the ratio of glycolytic-oxidative enzyme activities was lowest in type 1 muscle fibers but highest for type IIb, with an average value in type IIa. The ratios were comparatively smaller in normal subjects than obese and type 2 diabetes.
Ratios for oxidative enzyme activity-lipid content in Figure 3B determined that the values were lower in obesity and type 2 diabetes regardless of fiber type. These values were also similar across three fiber types in normal subjects.
Data from Table 1. confirms the theory that as the concentration of glucose increases so will the absorbance of the solution when examined with the glucose oxidase/horseradish peroxidase assay. Glucose within the context of this assay is determined by the amount of ferricyanide, determined by absornace, which is produced in a one to one ratio.1 Furthermore when examining the glucose standards, a linear calibration curve was able to be produced (shown as Figure 1). Noted the R2 value of the y = 1.808x - 0.0125 trend line is 0.9958, which is statistically considered linear. From this calibration curve the absorbance values of unknowns samples can be compared, and the correlated glucose concentration can then be approximated.
The data collected during this experiment has shown that a relationship likely exists between the rate of muscle fatigue and the time spent performing vigorous exercise prior to the set of repetitive movements. This is likely due to a build-up of lactic acid and lactate as a result of anaerobic respiration occurring to provide energy for the muscle cell’s movement. As the pH of the cell would have been lowered, the enzymes necessary in the reactions would likely not be working in their optimum pH range, slowing the respiration reactions and providing an explanation to why the average number of repetitions decreased as the prior amount of exercise increased.
Submaximal and maximal exercise testing are two analytic methods that can be used to examine the cardiovascular, and cardiorespiratory fitness/health levels of the individual being examined. Submaximal testing is usually preferred over maximal mainly because the submaximal exam is more practical in a fitness/health environment. Both test require the individual being examined to perform controlled exercise on a(n) treadmill/ergometer until either steady state has consecutively been reached (submax), or the individual reaches their max (close to it). Being that both test are set to exceed time limits of more than 3 minutes we examine the use of the ATP-PC, Glycolytic, and Oxidative energy systems. Although a huge portion of the test involves the use of the oxidative energy system, we must remember that the three systems are co-occurrent.
The first activity was isolating the gastrocnemius muscle. A cut between the thigh and hip was made so the skin can be pulled down past the lower leg. Then the tendon was cut away from the bone of the heel and one end of the nine-inch string was tied to the tendon. This led to the isolation of the sciatic nerve, found between the hamstring and heel on the lateral side of the thigh. Using fingers, the seams along the quadriceps and hamstring underwent a blunt dissection. In doing so, the glass-dissecting probe was used to free the sciatic nerve embedded in the tissues. A four-inch string was inserted between the nerve and the tissues. Then the transducer was calibrated using a fifty-gram block under the “Frog Muscle” program. Parameter of CAL 1 was changed to zero grams and CAL 2 was changed
Every day we use our skeletal muscle to do simple task and without skeletal muscles, we will not be able to do anything. Szent-Gyorgyi (2011) muscle tissue contraction in rabbit’s muscles and discovered that ATP is a source for muscle contraction and not ADP. He proposed a mechanism to cellular respiration and was later used by Sir Hans Krebs to investigate the steps to glucose catabolism to make ATP. In this paper, I will be discussing the structure of muscle fibers and skeletal muscles, muscle contraction, biomechanics, and how glucose and fat are metabolized in the skeletal muscles.
This lab experiment was conducted in a Texas Woman’s University exercise physiology lab room, on September 20, 2013. It consisted of two main participants: A trained participant (Male; 30 years old; 72 in. tall; 82.9 kg) and an untrained participant (Female; 20 years old; 65 in. tall; 75 kg). They were selected by my Prof. April Hartman to participate because they were best qualified to conduct the study in our class. Both participants were assigned to carry out the same experimental task. The Bruce Protocol (graded test) on a treadmill (mode of exercise) was used to conduct the VO2max test. The materials needed were: 1 metabolic cart (with computers); 2 mouthpieces; 1 nose clip; 1 treadmill; 1 RPE scale; 1 timer; pen; paper; and a HR monitor.
This report will explore the structure and function of skeletal muscle within the human body. There are three muscle classifications: smooth (looks smooth), cardiac (looks striated) and skeletal (looks striated). Smooth muscle is found within blood vessels, the gut and the intestines; it assists the movement of substances by contracting and relaxing, this is an involuntary effort. The heart is composed of cardiac muscle, which contracts rhythmically nonstop for the entire duration of a person’s life and again is an involuntary movement of the body. The main focus of this report is on skeletal muscle and the movement produced which is inflicted by conscious thought unless there is a potentially harmful stimulus and then reaction is due to reflex, as the body naturally wants to protect itself. Skeletal muscle is found attached to bones and when they contract and relax they produce movement, there is a specific process that the muscle fibers go through to allow this to occur.
James’s biopsy of his right gastrocnemius muscle would have shown a degeneration of the muscle or skeletal fibers due to the lack of dystrophyn. Another microscopic change that would be noticed is the accumulation of white blood cells. White blood cells have a very specific function which is to clear the damaged muscle fibers from the debris. Clearly, due to some of the muscle fibers being damaged other healthy fibers that have not been damaged appear denser. By having damaged muscle fibers, all the work rest upon the healthy fibers making them contract to the fullest due to the fact that the myosin and acting would have to overlap even more to make the muscle work.
Skeletal, smooth, and cardiac muscles play a vital role in the everyday processes that allow the human body to function. Without these muscles, everyday tasks and functions could not be conducted. Injury to these muscles could cause serious problems, however, these muscles have the ability to regenerate, repair, and fix multiple problems all by themselves. Repair and regeneration of a muscle are two similar, yet different things. Repair restores muscle continuity so that it can continue to function in the same way as before injury, but does not completely restore the pre-injury structure like regeneration (Huijbregts, 2001). Muscle repair and regeneration take place after an injury, after surgery, after atrophy, and even after working out.
Glycemic index is the measure of how quickly blood glucose rise after eating a particular kind of food. This is used by estimating the how much each gram of carbohydrate consumed raises a person’s glucose level. During intense exercise, the body uses glucose as energy source before it starts relying of fats. “Prolonged exercise can only be continued when there is an adequate amount of carbohydrate available to fuel muscle and the brain”(William,2004). This shows that the amount of carbohydrate/glucose that is found within the body’s tissue has a significant amount of influence to play on how effective the early hours of an exercise would be. Glycemic index helps one to know how effective the carbohydrate/glucose within the body is functioning during exercise.
Exercise has an effect on the body similar to that of insulin by stimulating cell to take up blood glucose fo...
When observing both cell types under a microscope several differences are obvious. Firstly, skeletal muscles are larger than smooth muscle cells (one muscle cell can be up to 100µm in length). They are also multinucleated whilst smooth muscle cells are uninucleate (Alberts et al, 2002: 961). Additionally, skeletal muscle cells appear to be striated, whereas smooth muscle cells do not show this banding pattern; but are instead smooth and tapered. The absence of this patterning in smooth muscle cells suggests that they consist of a less organised collection of contractile fibres (Silverthorn, 2007: 397). This banding pattern in skeletal muscles is known as the sarcomere.
Miller, SI and Wolfe, RR. "Physical exercise as a modulator of adaptation to low and high carbohydrate and low and high fat intakes." European Journal of Clinical Nutrition. 53:112-9, Apr. 1999
Heart failure is a condition in which the heart muscle becomes too weak to maintain an adequate cardiac output to meet the body’s oxygen demands (Wilmore, et al., 2008). Hypertension is a sustained condition when the blood pressure exceeds 140/90 mm Hg. It is estimated that about thirty percent of people ages fifty and over have hypertension. Type II diabetes is considered a milder form of diabetes and is characterized by impaired insulin secretion, impaired insulin action, or excessive glucose output from the liver (Wilmore, et al., 2008). The consequences of uncontrolled and untreated Type II diabetes, however, are the just as serious as those for Type I. This form is also called noninsulin-dependent diabetes, a term that is somewhat misleading. Many people with Type II diabetes can control the condition with diet and oral medications, however, insulin injections are sometimes necessary if treatment with diet and oral medication is not working. Gallbladder diseases from obesity mainly consist of Cholecystitis which is inflammation of the gallbladder. Osteoarthritis is a progressive disorder of the joints caused by gr...
“Fibroblast responses to variation in soft tissue mobilization pressure.” Medicine and Science in Sports and Exercise. April 1999: 531-5. Hargrove, Eugene C., ed. Animal Rights/Environmental Ethics Debate, Inc. Environmental Perspective.