10 mins of activity 90 atp made aerobically lactic

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

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...
View Full Document

Ask a homework question - tutors are online