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60 questions
Which term does NOT describe smooth muscle cells?
Skeletal
nonstriated
visceral
InvoluntaryCh 6 Skele
The type of muscle shown is this image is ______.
What organelle wraps and surrounds the myofibril and stores calcium?
sarcolemma
cross bridge
sarcomere
sarcoplasmic reticulum
Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ________.
extensibility
contractibility
irritability
elasticity
One neuron and all the skeletal muscles it stimulates is known as a ________.
Motor Unit
Synaptic Cleft
sarcoplasmic reticulum
neuromuscular junction
Striated involuntary muscle tissue found in the heart is ________.
cardiac
skeletal
smooth
dense regular
What is covered by the endomysium?
an individual muscle cell
myofibrils
an entire muscle
fascicles of muscle cells
The plasma membrane of a skeletal muscle cell is called the ________.
sarcomere
sarcoplasmic reticulum
sarcolemma
sarcoplasm
myofilament
What creates the alternating light and dark bands that provides the striation pattern on skeletal muscle tissue?
A bands and I bands
sarcoplasm and sarcolemma
thick filaments and myosin heads
H zones and M lines
Z discs and H zones
_______ muscle contracts most quickly upon stimulation?
Which of the following is NOT a function of the muscular system?
maintenance of posture
stabilization of joints
blood cell formation
production of movement
generation of heat
A sarcomere is ________.
the area between two intercalated discs
the contractile unit between two Z discs
a compartment in a myofilament
the nonfunctional unit of skeletal muscle
the wavy lines on the cell, as seen in a microscope
Which one of the following is composed mostly of the protein myosin?
Z discs
thick filaments
thin filaments
all myofilaments
light bands
The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscle contraction.
motor units
neuromuscular junctions
cross bridges
synapses
The H zone, located within the A band, lacks thin filaments and is represented by label ________.
Cardiac muscle fibers are joined by special gap junctions called intercalated discs; these discs allow heart activity to be closely coordinated.
True
False
Smooth muscles stabilize joints of the skeleton.
True
False
The formation of cross bridges requires both calcium ions and ATP.
True
False
The sarcoplasmic reticulum wraps like a sleeve around the myofibril and stores and releases calcium.
True
False
Cardiac and skeletal muscle both possess striations.
True
False
The epimysium is represented by label ________.
The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine.
True
False
Depolarization of a skeletal muscle cell leads to the opening of more channels that only allow potassium entry.
True
False
Voluntary muscle tissue
Smooth
Skeletal
Cardiac
A neuromuscular junction consists of one neuron and all the skeletal muscles it stimulates.
True
False
Muscle tissue found only in the heart
Smooth
Skeletal
Cardiac
Muscle tissue that activates arrector pili muscles to stand hairs on end
Smooth
Skeletal
Cardiac
The striations seen in skeletal muscle are actually alternating dark A and light I bands.
True
False
Muscle tissue that dilates and constricts the pupils of our eyes
Smooth
Skeletal
Cardiac
Muscle tissue composed of branching cells and intercalated discs
Smooth
Skeletal
Cardiac
Performs very slow, sometimes rhythmic, contractions
Smooth
Skeletal
Cardiac
Muscle tissue that maintains posture, body position, and stabilizes joints
Smooth
Skeletal
Cardiac
The myofilament composed of actin is indicated by label ________.
Specific neurotransmitter that stimulates skeletal muscle cells
Sodium Ions
synaptic cleft
acetycholine
calcium ion
action potential
Chemical that enters a muscle cell upon excitation
Sodium Ions
synaptic cleft
acetycholine
calcium ion
action potential
Muscle tissue that is multinucleate
Smooth
Skeletal
Cardiac
Gap between the axon terminals and the plasma membrane of a neighboring muscle cell
Sodium Ions
synaptic cleft
acetycholine
calcium ion
action potential
Electrical current that travels the length of the sarcolemma that results in the contraction of the muscle fiber
Sodium Ions
synaptic cleft
acetycholine
calcium ion
action potential
You have lost the labels to your muscle tissue slides in laboratory. Explain the characteristics that allow you to distinguish among skeletal muscle, smooth muscle, and cardiac muscle tissue.
Enzyme that breaks down acetylcholine (ACh)
Sodium Ions
synaptic cleft
acetycholinesterase
calcium ion
action potential
During skeletal muscle contraction, to what do myosin heads bind?
actin filaments
Z discs
the H zone
thick filaments
myosin filaments
The movement of a limb toward the body midline
flexion
supination
abduction
adduction
Type of movement that decreases the angle of the joint
flexion
supination
abduction
adduction
Type of movement that allows you to carry a soup bowl
flexion
supination
abduction
adduction
The sarcoplasmic reticulum stores this chemical
Sodium Ions
synaptic cleft
acetycholine
calcium ion
action potential
The movement of a bone around its longitudinal axis
flexion
inversion
plantar flexion
rotation
The movement of a limb away from the body midline
flexion
supination
abduction
adduction
Type of movement that turns the sole of the foot medially
flexion
inversion
plantar flexion
rotation
What enzyme breaks down acetylcholine into acetic acid and choline to prevent continued contraction of the muscle fiber?
sarcoplasmic reticulum
potassium ions
calcium ions
acetylcholinesterase
cross bridges
Fascicle arrangements produce skeletal muscles with different structures and functional properties, and determine their individual range of motion and power. List the seven different fascicle arrangements of human skeletal muscles and give a specific example of each.
The I band within a skeletal muscle fiber is indicated by label________.
The A band within a myofibril is indicated by label ________.
What must rush into a muscle cell to promote its depolarization?
calcium ions
sodium ions
acetylcholinesterase
potassium ions
acetylcholine
The perimysium wraps a fascicle of muscle cells and is represented by label ________.
The muscle fiber (cell) is indicated by label ________.
The endomysium that wraps individual muscle fibers is indicated by label ________..
Why are calcium ions necessary for skeletal muscle contraction?
Calcium ions cause ATP binding to actin.
Calcium ions trigger the binding of myosin heads to actin filaments.
Calcium ions bind to regulatory proteins on the myosin filaments, changing both their shape and their position on the thick filaments.
Calcium ions increase the speed of the action potential transmitted along the sarcolemma.
Calcium ions release the inhibition on Z discs.
The mechanical force of contraction is generated by ________.
shortening of the thick filaments
the temporary disappearance of thin filaments
shortening of the thin filaments
the "accordion-like" folding of thin and thick filaments
a sliding of thin filaments past thick filaments
What is acetylcholine?
a neurotransmitter that stimulates skeletal muscle to contract
a component of thick myofilaments
an oxygen-binding protein
a source of energy for muscle contraction
an ion pump on the postsynaptic membrane
The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell is called the ________.
neuromuscular junction
sarcomere
synaptic cleft
motor unit
cross bridge
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