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WorksheetsMuscle Contraction
Total questions: 54
Worksheet time: 28mins
What neurotransmitter is used at the neuromuscular junction that sends a signal from the motor neuron to the skeletal muscle?
Glutamate
Acetylcholine
Norepinephrine
Dopamine
What is the function of acetylcholine?
ACh binds to receptors on the sarcolemma and opens ion channels
ACh binds to receptors on the sarcolemma and closes ion channels
ACh binds to ion channels and open them
ACh binds to ion channels and closes them
Calcium inside the muscle cell binds to which filament, causing a shape change and revealing the active sites.
Actin
Myosin
Troponin
Tropomyosin
What binds to the active site on actin?
Actin
Myosin
Troponin
Tropomyosin
What is a cross-bridge?
When troponin and tropomyosin undergo a shape change
When the active site of actin is revealed
When the myosin heads bind to the actin active site
When the actin filaments slide past the myosin filaments
How do the actin filaments "slide"?
With the help of acetylcholine
With the help of ADP
With the help of ATP
With the help of calcium
When is ATP needed?
When actin slides
When myosin heads bind to actin
When myosin heads release from actin
When myosin slides
After the muscle is no longer stimulated, what occurs first
Acetylcholinesterase is released and removes ACh
The muscle continues to contract for a few more minutes
Enzymes break down calcium ions
The ion channels pump sodium back out of the cell and potassium back into the cell
Which ways do muscles get their energy from?
Creatine Phosphate
Anaerobic Respiration
Kreb Cycle
Aerobic Respiration
What is the most basic level of the muscular structure?
Sarcolemma
Sarcomeres
Fibers
fascicles
The actin is labeled here as _______.
AD
AC
BC
AB
The myosin is labeled here as _______.
BD
AC
BC
AB
Which of the following occur when ATP binds to the myosin head?
Myosin head change to low energy configuration
Myosin head undergoes power stroke
Myosin head detach from actin
Myosin head forms cross bridge
Ca2+ released by sarcoplasmic reticulum will bind to
Actin
Troponin
Myosin
Tropomyosin
where the terminal branches of a motor neuron and the sarcolemma of a skeletal muscle fiber "join"
plasmodesmata
neuromuscular junction
gap junction
intercalated disc
During a muscle contraction...
actin pulls on the myosin
myosin pulls on the actin
tropomyosin pulls on the myosin
troponin pulls on the actin
Which of the following substances are absolutely necessary for muscle contraction?
ATP and Na+
ATP and Ca2+
ADP+P
ADP and Ca2+
__________ is attached to the Z line?
myosin
actin
thick filament
troponin
What is the contractile unit formed from Z line to Z line?
Sarcomere
T Tubule
Sarcoplasmic reticulum
Fascicle
____________ attaches to actin to form the cross bridge.
Troponin
Tropomyosin
Myosin
Calcium
What is released from the sarcoplasmic reticulum?
Inorganic phosphate
ADP
Calcium
ATP
What causes the muscle to stop contracting?
Lack of effort
Myosin-Heads fail to attach
Calcium Ions are pumped away
Muscle fibre tears
Which of the following are the regulatory protein in muscle contraction? (Multiple answer)
Sarcoplasmic reticulum
Actin
Troponin
Myosin
Tropomyosin
Rigor mortis occur because
Lack of calcium ions attach to tropomyosin
Lack of ATP attach to the myosin head
Muscle stiff due to lack of heat
Lactic acid accumulates in muscle
Which of the following refers to the muscle cell?
Myofibril
Myofilament
Fascicle
Muscle fiber
It is the part of the muscle structure that invaginations of the plasma membrane, which are present exclusively in striated muscle
Sarcolemma
T-tubules
Actin
Myosin
Which among the following is correct?
As long as Ca++ ions remain in the sarcoplasm to bind to troponin, and as long as ATP is available, the muscle fiber will continue to shorten.
As long as Ca++ ions is absent in the sarcoplasm to bind to troponin, and as long as ADP is available, the muscle fiber will continue to shorten.
As long as Na+ ions remain in the sarcoplasm to bind to troponin, and as long as ATP is available, the muscle fiber will continue to shorten.
As long as Ca++ ions remain in the sarcoplasm to bind to troponin, and as long as Na+ is available, the muscle fiber will continue to shorten.
What is the length between Z-lines of an actin molecule called?
fascicle
sarcomere
myosin binding site
sarcoplasmic length
What is the function of the sarcoplasmic reticulum?
stores phosphorus
stores calcium
stores sodium
stores potassium
Why is calcium needed for muscle contraction?
causes the binding of neurotransmitters to receptors
causes the binding of myosin to actin
increases the action potential
changes the shape of myosin
What structure is shown here?
neuromuscular junction
sarcomere
origin and insertion
synaptic cleft
The myosin is labeled here as _______.
BD
AC
BC
AB
The actin is labeled here as _______.
AD
AC
BC
AB
During full muscle contraction the A Band will...
disappear
increase in width
stay the same
decrease in width
During a muscle contraction the 'Z' Lines of the sarcomere will...
disappear
remain in place
move farther apart
move closer together
During a muscle contraction the H Zone will...
remain the same width
decrease in
width
increase in width
Which of the following occurs first in muscle contraction?
calcium ions exit the sarcoplasmic reticulum
Sodium Ion enters the sarcolemma
sodium ions bind to troponin
acetylcholine binds to the receptors in the sarcolemma
Which of the following occurs first in muscle contraction?
Myosin-actin cross bridges form
calcium ions bind to troponin
the troponin-tropomyosin complex moves away from the actin binding sites
ATP binds to the myosin head, which "let's go" of the thin filament
Ca2+ will be released from the sarcoplasmic reticulum when...
impulse reaches neuromuscular junction
ATP binds to sarcoplasmic reticulum
impulse transmitted along T-tubules
acetylcholine binds to ligand gated ion channels
