Question | Answer |
a dense layer of collagen fibers, surrounds entire muscle | epimysium |
a fibrous layer that divides the skeletal muscle into a series of compartments. | perimysium |
bundle of muscle fibers | muscle fascicle |
delicate C.T. that surrounds the individual skeletal muscle cells | endomysium |
stem cells that function in the repair of damaged muscle tissue | myosatellite cells |
collagen fibers of the C.T. layers merge to to form a bundle | tendon |
multinucleate cell | myoblast |
plasma membrane in skeletal muscle fibers | sarcolemms |
cytoplasm surrounding the myofibrils | sarcoplasm |
dense region of the sarcomere that contains thick filaments | A bands |
contains thin filaments but no thick filaments, extends from A band of one sarcomere to the A band of the next | I band |
repeating functional units | sarcomeres |
lighter region on either side of the M line | H band |
connects the central portion of each thick filament | M line |
mark the boundary between adjacent sarcomeres | Z line |
proteins that interconnect thin filaments of adjacent sarcomeres | actinins |
narrow tubes that are continuous with the sarcolema and extend into the sarcoplasm at tight angles to the cell surface | T tubules |
forms a tubular network around each individual myofibril | sarcoplasmic reticulum SR |
a graph of tension developing in muscle fibers | myogram |
begins at stimulation and typically lasts about 2msec. muscle fibers doesnt produce tension | latent period |
tension rises to a peak | contraction phase |
calium levels are falling, acitve sites are being covered by tropomyosin, and number of cross-bridges is declining | relaxation phase |
tension rises like the steps in a staircase | treppe |
all the muscle fibers controlled by a single motor neuron | motor unit |
motor units are activated on a rotating basis, some resting and some are active | asynchronous motor unit summation |
resting tension in a skeletal muscle | muscle tone |
tension rises and the skeletal muscle's length changes | isotonic contraction |
load is greater thatn the peak tension the muscle will elongate | eccentric contraction |
muscle as a whole does not change length, and the tension produced never exceeds the load | iosmetric contraction |
anaerobic breakdown of glucose to pyruvate in the cytoplasm of the cell | glycolysis |
normally provides about 95% of the ATP demands of a resting cell | Aerobic metabolism |
high-energy component muscles store | creatine phosphate CP |
can no longer perform at the required level of activity | fatigue |
shuffling lactate to the liver and of glucose back to muscle cells | Cori cycle |
amount of oxygen required to restore normal, pre-exertion conditions | oxygen debt or excess postexercise oxygen consumption (EPOC) |
most skeletal fibers in body called..... can reach peak twitch tension in .01 sec | fast fibers |
only have about half the diameter as fast fibers take three times longer to reach peak tension after stimulation | slow fibers |
fibers that contain little myoglobin and are relatively pale; resemble fast fibers | intermediate fibers |
enlargement of the stimulated muscle | hypertrophy |
reduction of muscle size,tone, and power | atrophy |
virus attacks motor neurons in the spinal cord and brin, causing muscular atrophy and paralysis (loss of movement) | polio |
occurs throughout body, beginning with the smaller muscles of the face, neck, and arms. typically begins 2-7 hours after death and disappears after 1-6 days | rigor mortis |