1 after ach attaches to its receptors at the

This preview shows page 36 - 45 out of 55 pages.

1.After ACh attaches to its receptors at the neuromuscular junction,the next step is:a)K+-gated channels openb)Ca++binds to troponinc)the T tubules depolarized)cross bridges attache)ATP is hydrolyzed
2.Which of these bands or lines does NOT narrow when skeletalmuscle contracts?
3.is a continuous contraction that shows no evidence ofrelaxation.
2.3.3.3 Define the optimal length-tension relationship formuscle in terms of muscle anatomyideallength-tension relationshipwhen muscle slightlystretched(Why??)supported by attachment to bonesFig. 9.20-
Figure 9.19: Length-tension relationships of sarcomeres in skeletal muscle
J. Carnegie, U of O2.3.3.4 Indicate the influence of load on the velocity and durationof skeletal muscle contractionFig. 9.24Velocity & Duration of Contraction depends on:1)Load:greater load = longer latent period = slower contraction = shortercontraction durationFig. 9.21
2.3.4.1 List the 4 sources of energy for musclecontraction and the conditions under whicheach energy source would be used1.Stored ATP:ATP for cross bridge movement & detachment;Ca++pumponly 4-6 sec stored ATP; regeneratedimmediately & continuously by(A2-A4)2.Direct phosphorylation of ADP by creatinephosphate:CP = unique high-energy molecule stored inmusclesCP+ADPcreatine+ATPenzyme =creatine kinase;butCP reservesquickly gone (CP & ATP = 15-20 sec; @maximum muscle power)J. Carnegie, U ofO
3.Aerobic respiration:high ATP yieldbutslower (many steps); requires continuous O2/nutrients4.Anaerobic glycolysis:only 2 ATP/glucose but O2not used and isfastusuallypyruvic acidthen enters aerobic pathway; but if ~70% activity forlong period, blood vessels compressed by muscles & aerobicrespiration tooslowpyruvic acidconverted tolactic acid; reconverted back to pyruvic acid onceexercise over; aerobic respiration used to replenish ATP storesanaerobic pathwayproduces ~5% ATP ofaerobicpathway, but is 2.5x faster>> important duringvigorousmuscle activitykbind/pubbooks/mcmurrygob/medialib/media_portfolio/text_images/FG23_09-02UN02.JPG
Fig. 9.20:Energy sources during short- and long-duration exercise
2.3.5.2define muscle fatigue, oxygen debtEnergy systems used during sports activities:weight lifting, diving, sprinting:ATP & CP-WHY??tennis, soccer, 100 m swim: almost entirelyanaerobic-WHY??Short bursts of doing something intenselymarathon runs, jogging:mainlyaerobic; butanaerobicmay function untilaerobicreaches full efficiencyaerobic endurance:length of time a muscle can useaerobicanaerobic threshold:point at which muscle converts toanaerobicMuscle Fatigue= state ofphysiological inability to contractmajor contributor:ion imbalances(e.g. K+imbalancesinfluence membrane potential of muscle cells anddecreases Ca+release from SR)J. Carnegie, UofO
C.Oxygen Debtpost exercise need to:replenishO2reserves, convertlactic acidtopyruvic acid, replaceglycogen

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 55 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Spring
Professor
KCalvin
Tags
pH, muscles, J Carnegie

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture