Question: The inside of a muscle fiber membrane has a __ charge compared to the outside.
Answer Options:
neutral
positive
negative
Answer: negative
Question: The function of the Na+/K+ pump is to
Answer Options:
prevent Na+ from entering the cell
keep all negative ions inside the cell
make new ATP for the cell
maintain the ion gradients
Answer: maintain the ion gradients
Question: The concentration of sodium (Na+) is greatest
Answer Options:
outside the cell
in the bone matrix
inside the cell
Answer: outside the cell
Question: What is the average resting membrane potential of a neuron?
Answer Options:
90 mV
-70 mV
-55 mV
-40 mV
Answer: -70 mV
Question: If sodium channels in the membrane of a cell were opened, you would expect
Answer Options:
the permeability of sodium to decrease
the space-time continuum to be disrupted
the cell to hyperpolarize
sodium to diffuse into the cell
Answer: sodium to diffuse into the cell
Question: In order for a muscle cell to contract, ___ must be present inside the cell.
Answer Options:
acetylcholine and norepinephrine
a bolt of lightning
calcium and ATP
acetylcholine esterase
Answer: calcium and ATP
Question: The region of the sarcolemma that is found at the neuromuscular junction is the
Answer Options:
transverse tubule
synaptic cleft
motor end plate
neurotransmitter vesicles
Answer: motor end plate
Question: The function of acetylcholine esterase is to
Answer Options:
break down acetylcholine into acetate and choline
stimulate the release of acetylcholine from the axon terminal
produce acetylcholine
Answer: break down acetylcholine into acetate and choline
Question: The space between the nerve cell and the muscle cell at the neuromuscular junction is known as the
Answer Options:
motor end plate
acetylcholine
synaptic cleft
axon terminal
Answer: synaptic cleft
Question: The vesicles found in the axon terminal of a neuromuscular junction contain
Answer Options:
calcium
calmodulin
acetylcholinesterase
acetylcholine
Answer: acetylcholine
Question: Choose the correct order for the events of excitation and contraction of a muscle cell
Answer Options:
calcium enters the axon terminal of the neuron
a wave of depolarization travels along the sarcolemma into the T tubules
calcium flows from the sarcoplasmic reticulum and combines with troponin to begin the contraction
acetylcholine is released and moves across the synaptic cleft
acetylcholine binds to its receptor on the motor end plate
Answer: 1, 4, 5, 2, 3 (In this order)
Question: The force exerted by a muscle to move a weight is the
Answer Options:
fulcrum
extension
load (resistance)
effort (tension)
Answer: effort (tension)
Question: A large muscle like the gastrocnemius in the lower leg has ___ as/than a smaller muscle like the lateral rectus muscle of the eye.
Answer Options:
smaller motor units made up of fewer muscle cells
no motor units
the same motor units
larger motor units made up of more muscle cells
Answer: larger motor units made up of more muscle cells
Question: Immediately following the arrival of the stimulus at a skeletal muscle cell there is a short period during which the events of excitation-contraction coupling occur.
Answer Options:
refractory
lag (latent)
relaxation
contraction
Answer: lag (latent)
Question: A weightlifter attempts to lift a weight from the floor but the weight is so heavy that he is unable to do so and his muscles stay the same length. The type of muscle contraction the lifter used was mostly
Answer Options:
isotonic contraction
isometric contraction
concentric contraction
eccentric contraction
Answer: isometric contraction
Question: If a muscle fiber is stimulated so frequently that there is no relaxation phase at all, this is called
Answer Options:
treppe
incomplete (unfused) tetanus
wave summation
complete (fused) tetanus
Answer: complete (fused) tetanus
Question: Muscle fatigue is
Answer Options:
lack of oxygen in a muscle cell
the length of time a muscle can make ATP
when a muscle is unable to contract
when metabolism switches to glycolysis
Answer: when a muscle is unable to contract