Muscle Physiology Quiz Verified A+

Muscle Physiology Quiz Verified A+ Aerobic exercises have this effect on skeletal muscle TISSUE: ️️Increase mitochondria and increase capillary network How would a drug that competes with acetylcholine for receptors at the synaptic cleft affect skeletal muscle? ️️Reduce Muscle Impulses Muscle Fiber ️️ Myofibril ️️Muscle fiber organelles. Composed of myosin protein (thick filaments) and actin protein (thin filaments) Fascicle ️️bundle of muscle fibers To improve anaerobic endurance, exercises include: ️️Swimming, biking, weight lifting, running Anaerobic Exercises ️️Absence of oxygen, high intensity, short duration, develops force, burns calories even when the body is at rest A body with a higher metabolism would be? ️️More muscular The more the white muscle cells the more likely you would exceed in ️️Sprinting The most important factor in decreasing the intercellular concentration of calcium ion after contraction is ️️Active transport of calcium into the sarcoplasmic reticulum Muscle Atrophy ️️An unused msucle shrinks, capillary networks shrink, mitochondria drops Two different muscles are the same size, but one of them is capable of much finer control than the other, this is because... ️️It is controlled by more neurons than the other muscle The amount of tension produced in the skeletal muscle as a whole is determined by the ️️Force depends upon the number of fibers stimulated Sarcomere ️️the contractile unit of a myofibril, which is made of of thick and thin filaments arranged in sarcomeres A Band ️️Myosin (dark portions) I Band ️️Actin (light poritons) Z LInes ️️where actin filaments are attatched The Neuromuscular Junction ️️A site where motor neurons meets the muscle fiber, separated by a gap called the synaptic cleft Muscle Fiber Contraction Steps ️️1. Acetylcholine is released 2. Muscle fiber is stimulated 3. Calcium ions diffuse out of the sarcoplasmic reticulum 4. Linkages form between actin and myosin, actin slides inward Muscle FIber Contractions ️️"all or none" once it reaches the threshold it will contract (the cell, not the entire organ), different combinations of muscle fiber contractions give different movements. Force depends upon the number of fibers stimulated. Muscles will contract until they run out of energy, leading to muscle fatigue Muscle Fiber Relaxation ️️1. Cholinesterase decomposes acetylcholine, muscle fiber no longer stimulated 2. Calcium ions are transported back into the sarcoplasmic reticulum, calcium pump Muscle Fatigue ️️Muscle loses ability to contract, interruption in blood supply, lack of ATP, accumulation of lactic acid Creatine Phosphate (CP) ️️Muscle cells contain CP, CP transfers energy to ADP to regenerate ATP. CP creates one ATP per creatin phosphate for 15 seconds. This is where muscles go first for energy and it doesn't need ATP, in our muscles right now Anaerobic Respiration ️️Doesn't need oxygen, used when no oxygen is available, Glucose produces ATP (2 ATP per glucose) Lactic acid is produced (burning sensation) Energy for 30-60 seconds, leads to soreness because of lactic acid build up, causes fatigue sooner Aerobic Respiration ️️Needs oxygen, occurs in mitochondria, glucose produces 30 ATP per glucose, lasts for hours, will make carbon dioxide, if we run out of glucose, fatty acids are used as next energy source Slow Twitch Muscle Fiber ️️Contracting with slower intensity, more mitochondria, blood vessel invasion Fast Twitch Muscle Fiber ️️High contracting muscles, fibers prod