Which of the following statements regarding contraction in skeletal and smooth muscle is TRUE?
A. In skeletal muscle, calcium initiates contraction by binding to troponin, while in smooth muscle calcium initiates contraction by binding directly to myosin.
B. In skeletal muscle, calcium ions bind to a regulatory protein on thin filaments; in smooth muscle, calcium ions bind to a regulatory protein on thick filaments.
C. In skeletal muscle, calcium initiates contraction by binding to myosin light-chain kinase, while in smooth muscle calcium initiates contraction by binding directly to tropomyosin.
D. In skeletal muscle, calcium initiates contraction by binding to troponin, while in smooth muscle calcium initiates contraction by binding to calmodulin.
E.
All of the choices are true.
D
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A) calcitriol B) calcitonin C) inhibin D) cholecystokinin E) pancreatic polypeptide
Which of the following statements represents the force-velocity relationship for muscle tissue?
A. contraction is faster when the load is heavier B. contraction is slower when the load is heavier C. contraction is slower when the load is lighter D. the speed of contraction is not affected by the nature of the load
The external ear is called the:
a. auricle b. tympanic membrane c. pinna d. both A and C above
Which is TRUE about the condition anemia?
A. It can be caused by too little iron in the diet. B. It can be caused by kidney failure. C. It can be caused by abnormal hemoglobin. D. It results in reduced oxygen-carrying capacity of the blood. E. All of the above are true.