-
Individual skeletal muscle cells are known as
muscle fibers
-
All of the following are functions of skeletal muscle tissue except
cooling of the body
-
The three types of muscle tissue are
skeletal, cardiac, and smooth
-
The layer of dense irregular connective tissue that surrounds the entire
skeletal muscle is the
epimysium
-
What is the cell membrane of a muscle fiber called?
sarcolemma
-
Each of the following is an attribute of skeletal muscle fibers except
lack striations
-
A thick, fibrous connective tissue cord that attaches a muscle to a bone is
called
a tendon
-
What are the principal proteins of muscle contraction?
actin and myosin
-
Which structures extend into the sarcoplasm as a network of deep invaginations
of the sarcolemma?
transverse tubules
-
The functional contractile units of a skeletal muscle fiber are the
sarcomeres
-
A nerve impulse triggers the release of what chemical at a neuromuscular
junction?
acetylcholine (ACh)
-
Which term describes the expanded tip of an axon at a neuromuscular junction?
synaptic knob
-
Which part of a sarcomere contains entire thick filaments and lateral end
regions with overlapping thin filaments?
A band
-
When a muscle fiber contracts, what slides toward the center of each sarcomere?
the thin filaments of actin
-
A reduction in muscle size, tone, and power is called
atrophy
-
A muscle impulse travels deep into the muscle fiber along
T-tubule membranes
-
A single motor neuron, the muscle fibers it controls, and the neuromuscular
junctions in between constitute a
motor unit
-
When stimulated by a muscle impulse, what do the terminal cisternae release into
the sarcoplasm?
calcium ions, Ca2+
-
The arrangement of tendons and fascicles in a ____________ muscle resembles the
structure of a feather.
pennate
-
Types of skeletal muscle fibers include
- fast
- intermediate
- slow
- all of the above
-
Muscle fibers are arranged concentrically in
circular muscles
-
Types of pennate muscles include which of the following?
- multipennate
- bipennate
- unipennate
- all of the above
-
Attributes of a convergent muscle include all of the following except
fascicles insert obliquely onto a tendon extending through the muscle
-
The most common levers in the body are ____________ levers
third-class
-
Most muscles are attached at one end to a less movable point known as the
it is the main muscle that contracts to produce a particular movement
-
Which of the following describes a first-class lever
the fulcrum is situated between the force and the resistance
-
All of the following characteristics are used in naming muscles except
color
-
The deltoid muscle is named on the basis of its
shape
-
Of the following terms used in muscle names, which one refers to a specific body
region?
gluteus
-
Which of the following characterizes both skeletal and smooth muscle
cells?
excitable
-
The "muscular system" includes muscles in which of these locations?
surrounding the orbit
-
How do skeletal muscle fibers get multiple nuclei?
fusion of embryonic myoblasts
-
In skeletal muscle fibers, where do calcium ions occur at varying concentrations?
- in the terminal cisternae of the sarcoplasmic reticulum
- throughout the sarcoplasm
- in regions where the thin and thick filaments overlap
- all of the above
-
In what order would a scalpel first penetrate these layers of connective tissue
upon cutting into the biceps brachii muscle: (1) endomysium (2) epimysium (3)
perimysium
2, 3, 1
-
Which list of muscle structures proceeds from smaller to larger in diameter?
myofilament, myofibril, muscle fiber, fascicle
-
What are satellite cells?
unfused myoblasts
-
Blood vessels and nerve fibers that supply skeletal muscle fibers must penetrate
the
epimysium, perimysium, and endomysium
-
Synaptic knobs are to axons as ____________ are to
sarcolemmae, in that both are structural modifications involved in
transmitting electrochemical signals across the synaptic cleft.
motor end plates
-
Skeletal muscle contraction involves which of the following events?
- a nerve impulse followed by a muscle impulse
- release of calcium ions from terminal cisternae
- tropomyosin moving to expose active sites on actin molecules
- all of the above
-
Of the following, which is the first to occur during muscle contraction?
crossbridges link thick and thin filaments
-

In the sliding
filament mechanism, crossbridges are
myosin heads that bind to active sites on a thin filament
-

Interactions
between thick and thin filaments during muscle contraction occur in which
sequence?
attach, pivot, detach, return
-

What actually
shortens when a muscle fiber contracts?
sarcomeres, H zones, and I bands
-

How many motor
end plates does a typical skeletal muscle fiber contain?
only one
-

Rigor mortis
demonstrates that skeletal muscle tissue
- normally requires energy to end as well as to start a contraction
- can survive and function for some time after the heart stops beating
- maintains powerful contractions even with no ATP, until autolysis occurs
- all of the above
-

For any given
muscle, the total force exerted by a contraction depends on
the number of activated motor units
-

Physical
conditioning can effectively decrease the proportion of which type of
muscle fibers?
fast
-

Reflecting
their different needs, fast muscle fibers contain large ____________ reserves
whereas slow fibers contain the oxygen-carrying pigment ____________.
glycogen; myoglobin
-

An overdose of
cholinesterase inhibitors could produce effects most similar to those of
tetanus
-

Among the
patterns of fascicle arrangements, ____________ muscles can move their tendons
farther but ____________ muscles of the same size are stronger.
parallel; pennate
-

In the limbs,
the insertion of a muscle typically lies
distal to the origin
-

In terms of
ability to produce ATP, cardiac muscle fibers are most like
slow skeletal muscle fibers
-
Z discs
are to skeletal muscle as ____________ are to smooth muscle.
dense bodies
-

Aging affects
the muscular system in all of the following ways except
decrease in amount of connective tissue within muscles
-
The unit of muscle structure that is composed of bundles of myofibrils, enclosed
within a sarcolemma, and surrounded by a connective tissue covering called
endomysium is a
muscle fiber.
-

During the
contraction of a muscle fiber, myofibrils
shorten.
-

In a convergent
muscle, the fibers are
widespread over a broad area and joined at a common attachment site.
-

The plasma
membrane of a skeletal muscle fiber is called the
sarcolemma.
-

In a skeletal
muscle fiber, a triad is composed of
one transverse tubule and two terminal cisternae.
-

During
development, the ___ of a somite gives rise to skeletal muscle.
myotome
-

What is a
synaptic knob?
tendon.
-

The muscle that
assists the prime mover is called the
synergist.
-

Which of the
following changes in skeletal muscles is associated with aging?
Muscle fibers increase in diameter.
-
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