Human Physiology, 14th edition (2016)

358 Chapter 11 If a person has a 50% reduction in insulin sensitivity, what happens to insulin release for the person to remain ...

359 CHAPTER CHAPTER OUTLINE 12.1 Skeletal Muscles 360 Structure of Skeletal Muscles 360 Motor End Plates and Motor Units 361 12. ...

360 12.1 Skeletal Muscles Skeletal muscles are composed of individual muscle fibers that contract when stimulated by a somatic m ...

Muscle 361 an endomysium ( fig. 12.1 ). The endomysium is the basement membrane, or basal lamina, of the muscle fiber. Because t ...

362 Chapter 12 Figure 12.2 The appearance of skeletal muscle fibers through the light microscope. The striations are produced by ...

Muscle 363 terminal by an action potential causes the exocytosis of acetyl- choline (ACh) from about 100 synaptic vesicles, in a ...

364 Chapter 12 Figure 12.5 The components of a skeletal muscle fiber. A skeletal muscle fiber is composed of numerous myofibrils ...

Muscle 365 appearance because they contain only thin filaments. The thin filaments, however, do not end at the edges of the I ba ...

366 Chapter 12 appreciation of the three-dimensional structure of a myofi- bril can be obtained by viewing the myofibril in cros ...

Muscle 367 Figure 12.8 Titin filaments and M lines. The M lines are protein filaments in the middle of the A bands that join thi ...

368 Chapter 12 myosin head will then split ATP to ADP and P i , and—if noth- ing prevents the binding of the myosin head to the ...

Muscle 369 Figure 12.10 Activation of the myosin head. (1) The myosin head has an actin-binding site and an ATP-binding site, wh ...

370 Chapter 12 Role of Ca^2 1 in Muscle Contraction Scientists long thought that Ca^2 1 only served to form the calcium phosphat ...

Muscle 371 The position of the troponin-tropomyosin complexes in the thin filaments is thus adjustable. When Ca^2 1 is not attac ...

372 Chapter 12 action potentials. The stage is now set to explain exactly how a motor neuron stimulates a muscle fiber to contra ...

Muscle 373 The membrane of the sarcoplasmic reticulum also con- tains a type of Ca^2 1 release channel that opens in response to ...

374 Chapter 12 in response to the activation of motor units. By this means, the contractions of skeletal muscles can be graded, ...

Muscle 375 fig. 12.4 ). When the motor axon is activated, all of the muscle fibers it innervates contract. So, how can we produc ...

376 Chapter 12 these muscles also contract eccentrically when you jog down- hill or hike down a steep mountain trail. Series-Ela ...

Muscle 377 In the body, this normal resting length is maintained by reflex contractions in response to passive stretching (descr ...