Exam 3 Practice Questions Flashcards
Which of the following generates force during sliding filament contraction?
myosin
Which of the following binds calcium?
troponin
Where is calcium stored in skeletal muscle?
sarcoplasmic reticulum
Which of the following are required for actin/myosin contraction?
ATP and Ca
Peter has a condition in which there is no calcium within his skeletal muscle. As a result, he has:
no muscle contraction
Which of the following occurs first in contraction of
skeletal muscle:
motor neuron action potential
Which of the following occurs in skeletal muscle at rest:
Ca storage in sarcoplasmic reticulum
Acetylcholine (ACh) is critical for:
generation of sarcolemmal action potential
A person with a mutation in actin that prevents myosin binding will have:
lack of muscle tone
John is showing off for his friends and tries to use his biceps to lift the front end of a Peterbilt semi truck. This is an example of:
isometric contraction
At rest, which of the following muscle proteins binds calcium:
none of the above; Ca is in the SR at rest
During muscle contraction, which of the following binds ATP:
myosin
When acetylcholine is bound by receptors at the sarcolemma, what happens next?
sarcolemmal action potential
Acetylcholinesterase is an enzyme that breaks down acetylcholine at the neuromuscular junction. Acetylcholinesterase is important for:
ending muscle contraction
Curare is a plant-derived poison, traditionally used by indigenous people of South America for arrows and blowguns. When injected, curare reversibly prevents acetylcholine from binding to its receptor at the sarcolemma.
This will:
prevent muscle contraction
Curare is a plant-derived poison, traditionally used by indigenous people of South America for arrows and blowguns. When injected, curare reversibly prevents acetylcholine from binding to its receptor at the sarcolemma.
This will:
prevent muscle contraction
In a skeletal muscle cell, an action potential is conducted along:
the sarcolemma and t tubules
What causes action potentials in skeletal muscle cells?
ACh binding to its receptors
Acetylcholinesterase degrades Ach in the neuromuscular junction. A drug that inhibits acetylcholinesterase will cause:
increased muscle contraction
What protein binds calcium to activate contraction of
smooth muscle cells?
calmodulin
Smooth muscle is different from skeletal muscle because:
gap junctions allow smooth muscle cells to communicate with each other
Which of the following muscles elevates the ribs for inspiration/inhalation:
external intercostals
What is this muscle(shoulder)?
deltoid
What muscle originates at the zygomatic arch and contracts to close the mouth:
masseter
What muscle is this(upper back):
trapezius
Action potentials are transmitted along:
axons
Which are responsible for forming the myelin sheath around neurons of the Peripheral Nervous System:
Schwann cells
A motor neuron activates muscle fibers in the arm. It is part of:
The efferent division of the peripheral nervous system
During the depolarization phase of an action potential:
Sodium (Na+) channels open in the axolemma.
CNS neurons have a high metabolic demand. Where do they obtain glucose to support metabolism:
astrocytes
