10 mins of activity 90 atp made aerobically lactic

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Unformatted text preview: enzymes: myokinase & creatine kinase transfer myokinase creatine ATP Sources (cont.) ATP Immediate (cont.)~ • CP (creatine phosphate)= energy-storage molecule that )= donates the P donates • ATP & CP= phosphagen system, provides most energy ATP phosphagen provides used in short bursts of intense activity used Short-term~ above system exhausted, shifts to anaerobic above fermentation until heart/lungs can get more O2 to cells fermentation • 30-40 sec max activity (run diamond, basketball court) • Glycogen & blood glucose used to make ATP + lactic acid • Glycogen-lactic acid system Long-term~ approx. 40 sec, cardiopulmonary functions approx. ‘catch up’ & O2 delivered fast enough for aerobic respiration respiration Fatigue & Endurance Fatigue Long-term (cont.)~ • 10+ mins of activity, 90% ATP made aerobically • [Lactic acid] in muscle is small @ this stage, however, [Lactic aerobic respiration cannot continue indefinitely aerobic • Depletion of glycogen & bld glucose, loss of fluids & Depletion electrolytes limits endurance & performance electrolytes Fatigue= progressive weakness & loss of contractility progressive resulting in prolonged use of muscles resulting Endurance= depends on supply of organic nutrients depends (glucose, fatty & amino acids) amino • Dietary supplements for ‘carbohydrate loading’ • Endurance training doesn’t significantly build strength (& Endurance resistance training doesn’t build endurance) Cardiac & Smooth Muscle Cardiac Know the differences between cardiac, smooth, and skeletal Know cardiac smooth and skeletal muscle (recall Chapter 5’s material) muscle Cardiac~ • Heart tissue; striated muscle fibers (cardiocytes) that are Heart striated that shorter, thicker than skeletal w/ branched ends branched • 1 nucleus/cell, while skeletal has 3-4 nuclei/cell • Intercalated discs join ‘notched, or branched’ ends • Gap junctions w/in discs allow for electrical information to pass rapidly from 1 fiber to adjacent fibers • Desmosomes (mechanical junctions) to hold fibers together when heart contracts • Pacemaker of right atrium contracts heart on own, it does not need the CNS to beat (autorhythmic) need • ANS controls heart rate & contraction length • Involuntary control, while skeletal is voluntary Smooth Muscle Smooth Smooth~ • Forms walls of organs, blood vessels, pulmonary airways, Forms piloerector muscle (hair follicle), iris (eye) piloerector • Fusiform myocytes (short muscle fibers w/ tapering ends), 1 nucleus/cell nucleus/cell • Nonstriated because thick/thin filaments don’t line up, so don’t produce visible striations; Z-discs absent don’t • Intermediate filaments & thin myofilaments bind to Intermediate membrane plaques & dense bodies (protein masses w/in membrane dense cytoplasm) of adjacent fibers cytoplasm) • Involuntary control; some tissues contract w/o CNS control • Hormones, CO2, low pH, low O2; respond to stretch (stomach, respond bladder) • Autonomic nervous system controls rate of contractions (PNS Autonomic (rest & digest) & SNS (fight or flight) (rest...
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This note was uploaded on 01/12/2014 for the course ZOO 250 taught by Professor Staff during the Fall '08 term at S.E. Louisiana.

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