A & P Exam
4
The role of the drug neostigmine in the treatment of myasthenia gravis is to
partially block the action of acetylcholinesterase (AChE). Blocking AChE will
therefore result in... correct answersincreased stimulation of the muscle cell
The point where the axon terminal synapses with the muscle fiber
sarcolemma is called the . correct answersneuromuscular junction
Events of Excitation-Contraction Coupling in order: correct answers1. A
nerve impulse causes ACh to be released at a neuromuscular junction.
2. The T tubules carry the action potential to the interior of the muscle fiber.
3. Calcium ions are released into the sarcoplasm.
4. Calcium ions bind to troponin molecules on the actin myofilaments.
5.The troponin-tropomysin complex moves, exposing active sites
on the actin myofilaments.
6.The heads of myosin myofilaments bind to sites on the actin
myofilaments, forming cross-bridges.
The organophosphate poisons found in insecticides cause death by spastic
paralysis of the respiratory muscles. Which of the following may be a
mechanism of the poison? correct answersDecrease in acetylcholinesterase
activity
True or False
A skeletal muscle fiber (cell) contains a single nucleus. correct
answersFalse: A single skeletal muscle fiber contains multiple nuclei;
smooth muscle cells contain a single nucleus; cardiac muscle contains one
or two nuclei.
Examples of how muscles are used in include speaking, gesturing, and
facial expression. correct answerscommunication
Examples of how muscles are used to include sitting or standing
erect. correct answersmaintain tone (or posture)
Propelling and mixing food and propelling blood are examples of
functions of the
muscles in digestive tract and muscles of the heart,
respectively. correct answerssmooth; cardiac
The myofilaments that contain two strands of F actin coiled together to
form a double helix are myofilaments, and the
myofilaments that are composed of molecules that are shaped like golf
clubs are myofilaments. correct answersactin; myosin
, Sodium channels and some potassium channels are ; potassium diffuses
the cell. Inside of cell membrane is
charged relative to outside. correct
answersclosed; out of; negatively
Sodium channels are ; sodium diffuses the cell. Inside of cell
membrane becomes charged relative to outside. correct answersopen;
into; positively
The channels close; channels open; potassium diffuses out of
the cell. Again, the becomes negatively charged relative
to the
. correct answerssodium; potassium; inside of
the cell membrane; outside of the cell membrane
When you "pull your tummy in" and compress your abdomen, you use
the rectus abdominis, external abdominal oblique, internal abdominal
oblique, and transversus abdominis muscles. This is an example of
muscles working as .
correct answerssynergists
Why is the supraspinatus tendon the most commonly affected part of the
rotator cuff injury? correct answersIt has a relatively poor blood supply.
A facial muscle that originates on the mandible is the .
correct answersmentalis
Knee extension is performed by muscles of the quadriceps femoris group,
whereas knee flexion is performed by muscles of the hamstring group.
Based on this, which of the following statements is true? correct
answersThe hamstring muscles are antagonists of knee extension.
Supination of the forearm and hand is accomplished by the .
correct answersbiceps brachii and supinator
The fixed end of a muscle correct answersorigin
The mobile end of a muscle correct answersinsertion
A muscle that accomplishes a certain movement correct
answersagonist
A muscle that opposes a muscle that accomplishes a certain
movement correct answersAntagonist
Members of a group of muscles working together to produce a
movement correct answersSynergist
Muscles that hold one bone in place relative to the body while a usually
more correct answersFixator
4
The role of the drug neostigmine in the treatment of myasthenia gravis is to
partially block the action of acetylcholinesterase (AChE). Blocking AChE will
therefore result in... correct answersincreased stimulation of the muscle cell
The point where the axon terminal synapses with the muscle fiber
sarcolemma is called the . correct answersneuromuscular junction
Events of Excitation-Contraction Coupling in order: correct answers1. A
nerve impulse causes ACh to be released at a neuromuscular junction.
2. The T tubules carry the action potential to the interior of the muscle fiber.
3. Calcium ions are released into the sarcoplasm.
4. Calcium ions bind to troponin molecules on the actin myofilaments.
5.The troponin-tropomysin complex moves, exposing active sites
on the actin myofilaments.
6.The heads of myosin myofilaments bind to sites on the actin
myofilaments, forming cross-bridges.
The organophosphate poisons found in insecticides cause death by spastic
paralysis of the respiratory muscles. Which of the following may be a
mechanism of the poison? correct answersDecrease in acetylcholinesterase
activity
True or False
A skeletal muscle fiber (cell) contains a single nucleus. correct
answersFalse: A single skeletal muscle fiber contains multiple nuclei;
smooth muscle cells contain a single nucleus; cardiac muscle contains one
or two nuclei.
Examples of how muscles are used in include speaking, gesturing, and
facial expression. correct answerscommunication
Examples of how muscles are used to include sitting or standing
erect. correct answersmaintain tone (or posture)
Propelling and mixing food and propelling blood are examples of
functions of the
muscles in digestive tract and muscles of the heart,
respectively. correct answerssmooth; cardiac
The myofilaments that contain two strands of F actin coiled together to
form a double helix are myofilaments, and the
myofilaments that are composed of molecules that are shaped like golf
clubs are myofilaments. correct answersactin; myosin
, Sodium channels and some potassium channels are ; potassium diffuses
the cell. Inside of cell membrane is
charged relative to outside. correct
answersclosed; out of; negatively
Sodium channels are ; sodium diffuses the cell. Inside of cell
membrane becomes charged relative to outside. correct answersopen;
into; positively
The channels close; channels open; potassium diffuses out of
the cell. Again, the becomes negatively charged relative
to the
. correct answerssodium; potassium; inside of
the cell membrane; outside of the cell membrane
When you "pull your tummy in" and compress your abdomen, you use
the rectus abdominis, external abdominal oblique, internal abdominal
oblique, and transversus abdominis muscles. This is an example of
muscles working as .
correct answerssynergists
Why is the supraspinatus tendon the most commonly affected part of the
rotator cuff injury? correct answersIt has a relatively poor blood supply.
A facial muscle that originates on the mandible is the .
correct answersmentalis
Knee extension is performed by muscles of the quadriceps femoris group,
whereas knee flexion is performed by muscles of the hamstring group.
Based on this, which of the following statements is true? correct
answersThe hamstring muscles are antagonists of knee extension.
Supination of the forearm and hand is accomplished by the .
correct answersbiceps brachii and supinator
The fixed end of a muscle correct answersorigin
The mobile end of a muscle correct answersinsertion
A muscle that accomplishes a certain movement correct
answersagonist
A muscle that opposes a muscle that accomplishes a certain
movement correct answersAntagonist
Members of a group of muscles working together to produce a
movement correct answersSynergist
Muscles that hold one bone in place relative to the body while a usually
more correct answersFixator
