Answer Options:
True
False
Answer: True
Question: The extrinsic eye muscle motor units contain only 8 to 12 muscle cells and in some cases as few as 2 or 3 muscle cells.
Answer Options:
True
False
Answer: True
Question: Both first- and second-class levers operate at a mechanical disadvantage.
Answer Options:
A. True
B. False
Answer: B. False
Question: Which type of lever is demonstrated by using scissors?
Answer Options:
A. a first-class lever
B. a fourth-class lever
C. a third-class lever
D. a second-class lever
Answer: A. a first-class lever
Question: Which of the following is the correct sequence of events for muscle contractions?
Answer Options:
neurotransmitter release, motor neuron action potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke
motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments
muscle cell action potential, neurotransmitter release, ATP-driven power stroke, calcium ion release from SR, sliding of myofilaments
Answer: motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments
Question: In an isotonic contraction, the muscle ________.
Answer Options:
does not change in length but increases tension
never converts pyruvate to lactate
rapidly resynthesizes creatine phosphate and ATP
changes in length and moves the “load”
Answer: changes in length and moves the “load”
Question: What is the role of tropomyosin in skeletal muscles?
Answer Options:
Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules.
Tropomyosin is the chemical that activates the myosin heads.
Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the myosin molecules.
Answer: Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules.
Question: Excitation-contraction coupling requires which of the following substances?
Answer Options:
Ca²⁺ only
Ca²⁺ and ATP
ATP only
ATP and glucose
Answer: Ca²⁺ and ATP
Question: Bipolar neurons are commonly ______.
Answer Options:
Found in the retina of the eye
Found in ganglia
Motor neurons
Called neuroglial cells
Answer: Found in the retina of the eye
Question: If L = load, F = fulcrum, and E = effort, what type of lever system is described as LEF?
Answer Options:
A. second-class lever
B. first-class lever
C. third-class lever
D. fourth-class lever
Answer: C. third-class lever
Question: Which of the following is the correct sequence of events for muscle contractions?
Answer Options:
neurotransmitter release, motor neuron action potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke
neurotransmitter release, muscle cell action potential, motor neuron action potential, release of calcium ions from SR, sliding of myofilaments, ATP-driven power stroke
Answer: neurotransmitter release, motor neuron action potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke