PE 3070 Study Guide Exam 2
PE 3070 Study Guide Exam 2 PE 3070
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This 10 page Study Guide was uploaded by Aurora Moberly on Saturday October 1, 2016. The Study Guide belongs to PE 3070 at Southern Utah University taught by Dr. Julie Taylor in Fall 2016. Since its upload, it has received 44 views. For similar materials see Exercise Physiology in Physical Education at Southern Utah University.
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Date Created: 10/01/16
Chapter 2 Review Questions 1. What is bioenergetics? Is this different than metabolism? Bioenergetics is the process of converting substrates into energy. Metabolism is all of the chemical reactions in the body. 2. What is a calorie? Is this different than a kilocalorie? 1 kilocalorie is the amount of heat energy needed to raise 1L of water 1°C. 1 kilocalorie is equal to 1000 calories. 3. Ultimately what is the ONLY energy source for cellular work? ATP 4. The dietary substrates commonly used for energy production are the macronutrients (CHO, fat and protein) how many kcals of energy can be produced from one gram of each of these macronutrients? CHO and Protein are 4kcal/gram Fat is 9kcal/gram 5. Consider our body’s stores of CHO, fat and protein. Which of these macronutrients is stored in the human body in the greatest amounts (greatest energy stores)? Fat 6. Of the macronutrients, which substrate (CHO, fat, protein) provides MOST of the energy at rest? Which provides MOST of the energy during high intensity activity? Fat at rest, CHO during activity 7. Which macronutrient contributes very little to total energy production? What part of this type of macronutrient molecule cannot be oxidized and must be processed as urea? Protein, Nitrogen 8. Which macronutrient undergoes betaoxidation? What happens to a molecule during betaoxidation? Fat; The FFA molecule has a bond broken every two carbons and is converted into acetyl CoA. 9. What do the terms anaerobic and aerobic refer to with respect to energy systems? Aerobic requires oxygen for the energy system to work. Anaerobic does not require oxygen for the energy system to work. 10. Be able to describe the major energy pathways? ATPPCr, Glycolysis, Oxidative metabolism. ATPPCr breaks apart PCr to form ATP using creatine kinase. Myokinase system uses 2 ADP and breaks apart on ADP to form ATP with the other ADP. First 1015sec of exercise. Glycolysis begins with blood glucose or muscle glycogen. Blood glucose is broken down by hexokinase. Muscle glycogen is broken down by phosphorylase. PFK is the rate limiting enzyme and requires 1 ATP to work. Fast glycolysis (no oxygen) results in the production of two pyruvate converted into lactic acid. Oxidative glycolysis (oxygen) results in the production of two pyruvate converted into acetyl CoA. H produced during glycolysis are carried to the ETC via NAD. First 90sec of exercise. Oxidative metabolism begins with oxidative glycolysis that results in the production of acetyl CoA. Acetyl CoA enters the Krebs cycle which produces ATP, H and CO . The H 2from glycolysis and the Krebs cycle are transported to the ETC via + + NAD and FAD. The ETC uses H gradient to produce ADP. Oxygen at the end of ETC forms water with H . Virtually unlimited amounts of ATP produced, used for exercise going longer than 90sec. 11. Describe the end products from each of the major energy systems. Phosphagen (ATPPCr) Fast GlycolysisOxidative Phosphorylation (Initial Path Kreb’s Cycle Electron Transport Chain) Phosphagen Products: ATP and Creatine (ATPPCr) ATP and AMP (Myokinase) Fast Glycolysis: 2 ATP (Blood glucose) 3 ATP (Muscle Glycogen) 4 H (NAD) 2 Pyruvate => Lactic acid Oxidative Phosphorylation (CHO): Glycolysis: 2 ATP (Blood glucose) 3 ATP (Muscle Glycogen) 4 H (NAD) 2 Pyruvate => Acetyl CoA Krebs Cycle (2 Rounds): 2 ATP 12 CO 8 H (2 NAD 2 FAD) ETC: 25 ATP from H NAD 3 ATP from H FAD 23 ATP Glycolysis 2 ATP Krebs Water Total: 32 ATP (Blood glucose) 33 ATP (Muscle Glycogen) 12. What would be the primary energy system utilized during a 400 m sprint (less than 1 minute), shotput, 50 m sprint, marathon (3 hours)? During any activity, all energy pathways are active, what determines which is dominant? 400m Sprint: Fast Glycolysis ShotPut: Phosphagen System 50m Sprint: Phosphagen and Fast Glycolysis Marathon: Oxidative Phosphorylation 13. The Cori Cycle is a metabolic pathway in the liver that allows ___lactate___ to be converted to glycogen or glucose and made available to be transported via the bloodstream to working muscles for energy production. 15. When oxygen is present which energy substrates (CHO, protein and/or fat) enter the Kreb’s cycle and in what form do they enter the Kreb’s Cycle? CHO in the form of CoA 16. What is meant by “fat is burned in a CHO flame?” Pyruvate is the precursor to oxaloacetate, which is a critical molecule required for the Krebs cycle to function. If we don’t have CHO in the body, then there is no pyruvate which means that the Krebs cycle will not work efficiently and we won’t be able to burn fat. To burn fat, the body must have some CHO. 17. What is the role of NAD and FAD in metabolic pathways? To carry H to the electron transport chain. 18. Ultimately what is the role of oxygen in oxidative metabolism? To form water with H at the end of the electron transport chain 19. How many ATP can be generated from 1 glucose molecule through fast glycolysis? How about 1 glycogen molecule? 2 ATP; 3 ATP 20. How many ATP can be generated from the complete oxidation of 1 glucose molecule through slow glycolysis and the oxidative energy pathway? Glycogen? 32 ATP; 33 ATP 21. How many ATP can be generated from 1 fatty acid chain (16C, palmitic acid)? How about the entire triglyceride? 106 ATP; 138 ATP Recognize the following terms: Glycolysis: The breakdown of a glucose molecule Glycogenolysis: The breakdown of glycogen to glucose Gluconeogenesis: The process by which protein is converted into glucose Phosphocreatine: High energy molecule used in the ATPPCr system Kcal: The amount of heat energy needed to raise 1L of water 1°C Betaoxidation: Process in which FFAs are converted into acetyl CoA; Requires 2 ATP for activation Pyruvic Acid: End product of glycolysis that can be converted into lactic acid or Acetyl CoA depending on the presence of oxygen Acetyl CoA: The 6carbon molecule that enters and begins the Krebs cycle to produce hydrogen ions and ATP Glycogen: Storage form of glucose Cori Cycle: The enzymatic cycle that takes lactate and converts it to glycogen Aerobic: Process that occurs in the presence of oxygen Myoglobin: The primary oxygencarrying pigment of muscle tissue Lactic acid: Pyruvate is converted to lactic acid in the absence of oxygen Lactate: Lactic acid is disassociated into lactate and a hydrogen ion NAD: Carries hydrogen ions to the ETC, net production of ATP is 2.5 FAD: Carries hydrogen ions to the ETC, net production of ATP is 1.5 Kreb’s Cycle: Second step of oxidative phosphorylation ETC: Electron transport chain, third step in oxidative phosphorylation that produces the most ATP Anaerobic: Process that occurs without oxygen Lipolysis: The breakdown of fat stored as triglyceride into one molecule of glycerol and three molecules of FFA Enzymes: Protein that increases the rate of the reaction by lowering the energy of activation Bioenergetics: Process of converting substrates into energy; Performed at a cellular level Metabolism: Chemical reactions in the body Myosin ATPase: Releases energy from ATP on the myosin head Creatine Kinase: Breaks apart PCr to form ATP in the phosphagen system Myokinase: Breaks apart one ADP to form ATP from another ADP in the phosphagen system Hexokinase: Breaks apart one ATP to form glucose6phosphate from blood glucose to begin glycolysis Phosphorylase: Converts muscle glycogen to glucose6phosphate to begin glycolysis Phosphofructokinase (PFK): Rate limiting enzyme of glycolysis; Uses one ATP to convert molecules early in the glycolysis process Succinate Dehydrogenase: Complex II in the ETC and the only enzyme that participates in the Krebs cycle and the ETC Citrate Synthase: Catalyzes the first reaction in the citric acid cycle; The condensation of acetylCoA and oxaloacetate to form citrate Test: 10/5 PE 3070 Chapter 2: Bioenergetics and Muscle Metabolism Substrates: Fuel sources from which we make energy molecules (ATP): Carbohydrates (CHO), fat, protein Bioenergetics: Process of converting substrates into energy; Performed at a cellular level Metabolism: Chemical reactions in the body Catabolism: Breaks things down Anabolism: Building things ATP Only 40% of total energy consumed is used to generate ATP, 60% is released as heat ATP is a highenergy compound, the primary energy molecule for the human body, derived from food sources and local phosphorylation When the ATP molecule combines with water and ATPase the last phosphate group splits away releasing large amounts of free energy reducing ATP to ADP and P i Phosphorylation: A phosphate group is added to the lowenergy compound, ADP, to form ATP Local Phosphorylation: ATP production that occurs within the muscle cell Substrate Level Phosphorylation: ATP generated independent of oxygen Oxidative Phosphorylation: ATP generation that requires oxygen Energy Kilocalorie (kcal): The amount of heat energy needed to raise 1kg of water 1°C at 15°C CHO and Protein 4kcal/g; Fat 9kcal/g CHO CHO is the primary substrate (fuel) because it is an easier molecule to metabolize and is used in 2 out of 3 energy pathways CHO is found in the body as blood glucose, liver glycogen, muscle glycogen Fat Fat is less readily available because it has to be reduced from triglycerides to glycerol and free fatty acids (FFA) FFA are used to form ATP Protein Only used for energy during very long bouts of exercise or starvation Gluconeogenesis: The process by which protein is converted into glucose Lipogenesis: The process of converting protein into FFA Only the amino acids of protein can be used for energy Rate of Energy Production Rate is determined by: 1. Availability of the primary substrate 2. Enzyme activity 3. Availability of cofactors Mass Action Effect: Increased substrate availability increases the rate of the metabolism Enzymes: Proteins that speed up reactions by lowering the activation energy required to begin a reaction Many enzymes require cofactors to function so their availability can effect enzyme activity as well RateLimiting Enzyme: One enzyme that controls the rate of the reaction The three energy systems are (Fast to Slow): 1. Phosphagen System (Anaerobic metabolism) 2. Glycolysis (Anaerobic metabolism) 3. Oxidative Phosphorylation (Aerobic metabolism) All three systems are always active Phosphagen System: ATPPCr System and Myokinase System Initiates every muscular movement; Substrate level metabolism; CHO only Phosphocreatine (PCr): Highenergy molecule stored in cells This system can sustain the muscle’s energy needs for 315sec during high intensity exercise ATPPCr System: ATPPCr is used more than myokinase system PCr + ADP + Creatine kinase ATP + Creatine The energy released from the break of PCr is used to regenerate ATP Creatine Kinase: Enzyme that breaks the inorganic phosphate (P) from PCr i Activity is increased when concentrations of ADP or P are inireased Activity is inhibited when concentrations of ATP are increased Myokinase System: Not the preferred pathway because we don't have a lot of myokinase 2ADP + Myokinase ATP + AMP Glycolytic System 1. Glycolysis begins with a 6carbon glucose molecule (glucose6phosphate) Blood glucose is converted to glucose6phosphate by the enzyme hexokinase, this process costs one ATP Muscle glycogen is converted to glucose6phosphate by the enzyme phosphorylase, this doesn't cost any ATP 2. Phosphofructokinase (PFK): Rate limiting enzyme for glycolysis; Early in the glycolysis process; Uses 1 ATP If ATP concentrations are high the activity of PFK decreases If ADP and P cincentrations are high the activity of PFK increases 3. Fast Glycolysis: Glycolysis done in the absence of oxygen Produces 2 H that are transported to the electron transport chain (ETC) by coenzyme NAD 4. Aerobic Glycolysis: Glycolysis done in the presence of oxygen Produces 2 H that are transported to the ETC by coenzyme NAD 5. Pyruvate: End product of glycolysis + Fast glycolysis produces pyruvate converts it to lactic acid that dissociates into lactate and H Aerobic glycolysis produces pyruvate converts it to acetyl CoA using oxygen that then travels to the mitochondria to begin oxidative phosphorylation 6. Products of Glycolysis: Blood glucose glycolysis results in a net production of 2 ATP Muscle glycogen glycolysis results in a net production of 3 ATP + Glycolysis results in 4 H ions (2 from fast glycolysis 2 from aerobic glycolysis) Glycolysis results in 2 pyruvate molecules that can be converted to lactic acid or acetyl CoA + Fatigue from glycolysis occurs because of the buildup of H causing acidification of muscle fibers which impairs glycolytic enzyme function Acidification also decreases muscle fibers calciumbinding capacity impeding muscle contraction Glycolysis operates within the cell cytoplasm; Substrate CHO Glycolysis used during the first 2 minutes of exercise Cori Cycle: How the body processes lactic acid/lactate Lactate in the muscle diffuses into the blood stream then travels to the liver Lactate in the liver goes through a series of enzymatic (cori cycle) steps and is converted to glucose that can reenter the blood stream or it is converted to glycogen and stored in the liver Oxidative System: Overview Occurs in the mitochondria; Substrates can be CHO or fats Three main processes: Glycolysis, Krebs cycle, Electron transport chain (ETC) 1. 2 Pyruvic acids from glycolysis are converted to 2 acetyl CoA 2. Each acetyl CoA enters the Krebs cycle and produces ATP, carbon dioxide and H + + 3. H in the cell are carried by two coenzymes NAD and FAD to the ETC 4. ETC recombines H atoms with oxygen to produce ATP and water 5. ATP production results in 32/33 from glucose/glycogen or 100+ from FFA Oxidative System: Krebs Cycle 2 Krebs cycles occur due to the 2 acetyl CoA from glycolysis Products (2 Krebs cycles):8 H (6NAD 2FAD), 12 CO , 2 ATP 2 Oxidative System: Electron Transport Chain Every H that NAD drops off to the ETC results in 3 ATP but nets 2.5 + ATP because it costs energy to transport H + Every H that FAD drops off results in a net of 1.5 ATP At the end of the ETC H combines with oxygen to form water preventing acidification of the cell Net energy production is 33/34 ATP per molecule of glucose/glycogen Oxidative System: Fat Lipolysis: Fat is stored as triglyceride, lipolysis is the process of breaking down triglyceride into one molecule of glycerol and three molecules of FFA Lipases: Enzymes that break down triglycerides; Occurs in the fat cell βoxidation: Process in which FFAs are converted into acetyl CoA; Requires 2 ATP for activation Every two carbons of the FFA are broken off to form acetyl CoA (16carbon FFA would form 8 acetyl CoA) Every bond broken in FFA releases 2 H (1NAD 1FAD) (16carbon FFA would release 14 H ) + FFA requires more oxygen because FFA contains more carbon molecules than a glucose molecule “Fat’s Burn in a CHO Flame” means: Pyruvate is the precursor to oxaloacetate, which is a critical molecule required for the Krebs cycle to function. If we don’t have CHO in the body, then there is no pyruvate which means that the Krebs cycle will not work efficiently and we won’t be able to burn fat. To burn fat, the body must have some CHO Oxidative System: Protein Gluconeogenesis: The process by which protein is converted into glucose When amino acids are catabolized they release nitrogen which cannot be oxidized by the body Deamination: Removal of the nitrogen from amino acids Nitrogen can be used to form new amino acids or is converted to urea and excreted out of the body through urine This conversion requires the use of ATP Only 510% of energy is derived from protein Oxidative Capacity of Muscle Oxidative Capacity of Muscle: The maximal capacity of muscle to use oxygen Oxidative Capacity depends on: 1. Oxidative enzyme concentrations and activity 2. Fiber type composition and number of mitochondria 3. Endurance training 4. Oxygen availability (#1 determinate of the oxidative capacity of a muscle) 1. Oxidative enzyme concentrations and activity Enzyme activity can be measured using the enzymes succinate dehydrogenase and citrate synthase The more oxidative enzyme concentrations/activity a muscle has the greater its oxidative capacity 2. Fiber type composition and number of mitochondria Type I fibers have a greater capacity for aerobic activity because they have more mitochondria and high oxidative enzyme concentrations The more type I fibers a muscle has the greater its oxidative capacity 3. Endurance training Endurance training enhances the oxidative capacity of Type II fibers Endurance training develops more and larger mitochondria as well as more oxidative enzymes per mitochondria 4. Oxygen availability During exercise the body increases respiration, heart rate, force of heart beat, dilates arterioles, ect. to increase oxygen levels in the body The human body stores little oxygen so the oxygen entering the blood is directly proportional to the amount of oxygen used by tissues for oxidative metabolism Chapter 5: Energy Expenditure and Fatigue Measuring Oxidative Capacity Direct Calorimetry: Measures the body’s heat production to calculate energy expenditure Indirect Calorimetry: Calculates energy expenditure from the respiratory exchange ratio (RER) of CO and O2 2 RER RER equation: VCO /VO 2 2 RER value at rest is 0.80 and the range is from 0.701.0 The closer your RER is to 0.70 the more your body is relying on fats for fuel; Closer to 1.0 means your body is relying on CHO for fuel CHO RER: C H O 6> 12 A6 + 6CO + 6H O 2 2 CHO Requires 9 O to fully catabolize the glucose molecule, we already have 3 O from the glucose molecule 2 2 therefore we need 6 O fr2m the environment We get 1.0 for CHO RER because we produce 6 CO2 and consume 6 O therefore 6 CO 26 O = 1.0 2 2 Fat RER: C H 16 32 120ATP + 16CO + 16H O 2 2 Requires 24 O t2 fully catabolize this FFA, we already have 1 O from th2 FFA molecule therefore we need 23 O 2 form the environment We get 0.70 for Fat RER because we produce 16 CO2 and consume 1 O therefore 16 C2 /23 O = 0.70 2 2 Protein is not considered because of its minimal influence Isotopes Isotopes: Radioactive molecules that can be tracked for long term measurements of daily metabolism Carbon 13 can be infused in the body and is selectively traced to determine its movement and distribution 2 Doubly Labeled Water: H (deuterium) is infused with water and ingested; The rate at which the substrate leaves the body is monitored and used to calculate how much energy is expended Measuring Energy Expenditure Metabolic Rate: Rate at which the body expends energy at rest and during exercise measured as wholebody oxygen consumption and its caloric equivalent (Measured in kcals) Metabolism increases as exercise intensity increases Resting Metabolic Rate: Very similar to BMR except for the measurement conditions are not strictly controlled (Higher EE than BMR) Total Daily Energy Expenditure: The energy required for normal daily activity Basal Metabolic Rate: Minimum energy required for essential physiological function; Measured in very controlled conditions Factors that affect BMR: 1. Increased fatfree mass (muscle) increased BMR 2. Increased body surface area increased BMR 3. Increase in age gradually decreases BMR 4. Increased body temperature increased BMR 5. Increased stress increased BMR 6. Increased levels of thyroxine and epinephrine (stress hormones) increased BMR Maximal Oxygen Uptake Maximal Oxygen Uptake (VO 2max): Point at which O c2nsumption doesn’t increase with further increase in intensity Best single measure of aerobic fitness Factors affecting VO 2max 1. Sex 2. Body size 3. Age 4. Level of training Absolute VO 2max: Tells us about the energy expenditure of a person; ml or L of O con2umed per minute Relative VO 2max: Tells us about the fitness of a person; ml of O 2onsumed per kg body weight per min Equation: Body weight * ml of oxygen consumed Resting VO 2max .5 ml*kg *min ; Collegeage VO 2max 50 ml*kg *min 1 VO 2max increases with 812 weeks of training and then plateaus even with continued training but athletes can develop the ability to perform at a higher percentage of their VO 2max Anaerobic Effort Oxygen consumption is required for several minutes to reach fully functional aerobic processes and as a result the body experiences an oxygen deficit Oxygen Deficit: Occurs due to the difference in oxygen needs and supply during the transition from rest to exercise Excess PostExercise Oxygen Consumption (EPOC): Volume of oxygen consumed during the minutes immediately after exercise ends that is above normal consumption at rest Can tell us how much oxygen we got from anaerobic systems at the beginning of exercise Factors Responsible for EPOC: 1. Rebuilding depleted ATP supplies (Main cause of EPOC) 2. Clearing lactate produced by anaerobic metabolism 3. Replenishing O supplies borrowed from hemoglobin and myoglobin 2 4. Removing H and CO that2has accumulated in body tissues 5. Feeding increased metabolic and respiratory rates due to increased body temperature Lactate Threshold: Point during exercise when rate of lactate production exceeds the rate of lactate clearance Expressed as the percentage of maximal oxygen uptake %VO 2max Untrained adults have lactate threshold between 5060% VO 2max Elite endurance athletes have lactate threshold between 7080% VO 2max High VO and a high % VO are two major determinants of a successful endurance athlete 2max 2max The lactate threshold determines the fastest pace that can be tolerated during a longterm endurance event Wingate Test: Assessment of Peak Anaerobic Power and Anaerobic capacity Characteristics of Successful Endurance Athletes (In order of importance) 1. High VO 2max 2. High lactate threshold when expressed as a percentage of VO 2max 3. High economy of effort or a low VO for2a given absolute exercise intensity 4. High percentage of type I muscle fibers Fatigue: Inability to maintain the required power output to continue muscular work at a given intensity; Reversible through rest Can depend on type and intensity of exercise, muscle fiber type, training status and diet Four major causes of fatigue: 1. Inadequate energy delivery/metabolism 2. Accumulation of metabolic byproducts 3. Failure of muscle contractile mechanism 4. Altered neural control of muscle contraction Peripheral Fatigue: Fatigue caused by factors within the muscle Central Fatigue: Fatigue caused by changes in the brain or nervous system Energy Systems and Fatigue: 1. Fatigue coincides with PCr depletion 2. Fatigue is correlated with muscle glycogen depletion Sensation of fatigue in longterm exercise coincides with a decreased concentration of muscle glycogen Selected muscle groups may deplete more quickly than others Glycogen depletion and hypoglycemia limit performance in activities lasting longer than 6090min Glycogen Depletion causes fatigue because it 1. Acts as a regulator of several cellular functions that stop once it is gone 2+ 2. Interferes with excitationcontraction coupling and Ca release from the SR 3. Inorganic Phosphate accumulation during short term exercise contributes to fatigue Largest contributor to fatigue in short term exercise 2+ Piimpairs contractile function of myofibrils and reduces Ca release from the SR Increased ADP and P concentrations inhibits ATP breakdown through negative feedback i 4. Increased muscle temperature during exercise can increase the rate of CHO use and hasten glycogen depletion High muscle temperature impairs both muscle function and muscle metabolism Increased humidity caused early fatigue as well + Shortduration activities depend on anaerobic glycolysis and produce lactate and H + Cells buffer H with bicarbonate (HCO ) to3keep cell pH between 6.4 and 7.1 Bicarbonate Pathway: H + HCO → H3CO → C2 +3H O 2 2 pH below 6.9 inhibits PFK slowing glycolysis pH of 6.4 H levels stop any further glycolysis Acidosis reduces the rate of energy production (glycolysis and ATP production) (inhibits PFK) + H may displace calcium and interfere with crossbridge formation H may be major factor in maximal efforts of 2030 sec + H can inhibit O2 binding with Hb in the lungs + H can stimulate pain receptors pH is the major limiter of performance and the primary cause of fatigue during maximal exercise lasting more than 2030sec Reestablishing the pH of muscle requires 30min of recovery Factors of Neuromuscular fatigue 1. Decrease ACh synthesis and release 2. Altered ACh breakdown in synapse 3. Increase in muscle fiber stimulus threshold 4. Altered muscle resting membrane potential 2+ 5. Fatigue may inhibit Ca release from SR Central Nervous System and Fatigue The recruitment of muscle is partially controlled by the brain Central Government Theory: Processes occur in the brain that regulate power output by the muscles to maintain homeostasis and prevent unsafe levels of exertion that may damage tissues Limits exercise by decreasing the recruitment of muscle fibers Acute Muscle Soreness Muscle Strain: Pain felt during or immediately after exercise as a result of exercise end product accumulation and tissue edema Edema: Caused by fluid shifting from the blood plasma into the tissues and causes acute muscle swelling Acute Muscle Soreness: Soreness felt in the muscles immediately after exercise DelayedOnset Muscle Soreness (DOMS) DOMS: Muscle soreness felt a day or two after exercise Eccentric muscle action is the primary initiator of DOMS DOMS causes a reduction in the forcegenerating capacity of affected muscles due to 1. Physical disruption of the muscle 2. Failure within the excitationcontraction coupling process (most important) 3. Loss of contractile protein Sequence of Events in DOMS 1. High tension in the contractile elastic system of the muscle results in structural damage to the muscle and its cell membrane This structural damage is necessary for muscle hypertrophy 2. The cell membrane damage disturbs calcium homeostasis inhibiting cellular respiration Resulting high calcium concentrations activate enzymes that degrade the Zlines 3. Within a few hours there is a significant elevation in circulating neutrophils that participate in the inflammatory response Neutrophils: White blood cell that invades the injury site and release cytokins (attract other inflammatory cells) 4. The products of macrophage activity and intracellular contents accumulate outside the cells and stimulate the free nerve endings in the muscle Macrophages: Initial phase invades the damaged muscle fibers and remove debris; Second phase invades and aides in muscle regeneration 5. Fluid and electrolytes shift into the area creating edema (causes swelling and pain) Muscle spasms may be present Muscle Cramps ExerciseAssociated Muscle Cramps (EAMSC): Painful, spasmodic, involuntary contractions of muscles that occur during or immediately after exercise 1. Theory 1: EAMSCs occur because neuromuscular control becomes altered Excitation of the muscle spindle and inhibition of the Golgi tendon organ occur in fatigue muscles resulting in abnormal alpha motor neuron activity and reduced inhibitory feedback Stretching should prevent EAMSC 2. Theory 2: Heat cramps caused by electrolyte deficits Specifically deficient in sodium and chloride Fluid shifts from the interstitial compartment to the intravascular compartment causing neuromuscular junctions to become hyper excitable Treat by drinking a high salt solution, massage and ice the affected area
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