The actual contractile units of muscles extend from Z disc to Z disc. They are ________
A) sarcomeres B) sarcoplasmic reticulum
C) thick filaments D) myofibrils
Answer: A
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The mentalis muscle has what action?
A. Smiling B. Frowning C. Pouting D. Blowing E. Sucking
One way one can purify myosin from other skeletal muscle proteins is to immobilize actin on a column, pour a mix of the muscle proteins through, wash first to get out the nonspecific proteins and then do a second to wash to obtain myosin. Based on the contraction cycle, your first wash should
a. include ATP, but the second wash should not. b. not include ATP, but the second wash should. c. include ATP, as should the second wash. d. not include ATP, and neither should the second. e. should include calcium, but the second one should not.
Saltatory conduction of an action potential means that
A. once one action potential is created, it moves down the axon. B. the whole axon depolarizes at the same time. C. an action potential is conducted from one node of Ranvier to the next node. D. one action potential stimulates the production of a new action potential at the adjacent site.
This figure compares the organization of the somatic motor system and the autonomic nervous system. Identify structure "B" on the above diagram.
A. Somatic motor neuron B. Effector organ (smooth muscle of GI tract) C. Postganglionic neuron D. Preganglionic neuron E. Autonomic ganglion