human anatomy chapter 9 part 2
Which place in the body would you be likely to find smooth muscle?
Which unique quality of muscle tissue is defined as the ability to continue to contract over a range of resting lengths?
The fusion of the epimysium, perimysium, and endomysium at the end of a muscle is called a ____________.
Arrange the following terms in order from most superficial (largest) to deepest (smallest): myosin, sarcoplasmic reticulum, sarcolemma, and myofibril.
sarcoplasmic reticulum, sarcolemma, myofibril, myosin
In which part of the body would you be most likely to find muscle with a higher percentage of fast fibers?
Which of the statements is true of a synergistic muscle?
It supports an agonistic muscle and may stabilize a motion.
Action potential propagation in a skeletal muscle fiber ceases when acetylcholine is removed from the synaptic cleft. Which of the following mechanisms ensures a rapid and efficient removal of acetylcholine?
Acetylcholine is degraded by acetylcholinesterase.
The neuromuscular junction is a well-studied example of a chemical synapse. Which of the following statements describes a critical event that occurs at the neuromuscular junction?
Acetylcholine is released by axon terminals of the motor neuron.
Action potentials travel the length of the axons of motor neurons to the axon terminals. These motor neurons __________.
extend from the brain or spinal cord to the sarcolemma of a skeletal muscle fiber
Calcium entry into the axon terminal triggers which of the following events?
Synaptic vesicles fuse to the plasma membrane of the axon terminal and release acetylcholine.
Acetylcholine binds to its receptor in the sarcolemma and triggers __________.
the opening of ligand-gated cation channels
Sodium and potassium ions do not diffuse in equal numbers through ligand-gated cation channels. Why?
The inside surface of the sarcolemma is negatively charged compared to the outside surface. Sodium ions diffuse inward along favorable chemical and electrical gradients.