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A muscle fiber can be innervated by multiple motor neurons.
a) True
b) False - correct answer ✔✔f
The contraction time of a skeletal muscle is the time between initiation of stimulation and
peak contraction of the muscle.
a) True
b) False - correct answer ✔✔f
During contraction of all types of muscle cells, Ca++ initiates contraction by entering the
cytoplasm of the muscle cell by the process of facilitated diffusion.
a) True
b) False - correct answer ✔✔t
The plateau phase of the contractile cell action potential is caused by Na+ entering the cell.
a) True
b) False - correct answer ✔✔f
The radii of arterioles can be adjusted independently to variably distribute cardiac output
among organs.
a) True
, b) False - correct answer ✔✔t
Platelets contain actin and myosin.
a) True
b) False - correct answer ✔✔t
Ischemic heart disease is
a) Rapid but regular depolarizations and contractions
b) Rapid irregular uncoordinated depolarizations contractions
c) Action potentials not conducted between atria and ventricles
d) Over excitation of non-SA node autorhythmic regions of heart
e) Reduced blood supply to heart - correct answer ✔✔e
The steps of synaptic transmission at a neuromuscular junction are listed below, out of order.
Choose the correct order.
1. Acetylcholine binds to receptors on muscle cell.
2. Acetylcholine is released.
3. A graded potential is produced on the motor end plate.
4. An action potential is produced on the muscle cell membrane.
5. Channels for both sodium and potassium are opened.
6. Voltage-gated calcium channels on the plasma membrane open.
7. An action potential arrives at the axon terminal. - correct answer ✔✔7621534
The parasympathetic nervous system can act as a stimulus to which types of muscle cells?
a) Single-unit smooth
b) Cardiac autorhythmic