WorksheetsMuscle Physiology Quiz
Total questions: 18
Worksheet time: 6mins
Name
Class
Date
1.
The segment of a myofibril that is called a sarcomere runs from _______________.
a)
one Z line to the next Z line
b)
one H zone to the next H zone
c)
one A band to the next A band
d)
one end of a skeletal muscle to the opposite end
2.
Into what does the neuron release its neurotransmitter at the neuromuscular junction?
a)
motor end plate
b)
cytoplasm of the muscle cell
c)
terminal cisternae
d)
synapse
3.
A motor unit is made up of _______________.
a)
all the muscle fibers within a given muscle
b)
a motor neuron and the muscle fibers it innervates
c)
all the neurons going into an individual section of the body
d)
a fascicle and a nerve
4.
The crossbridges involved in muscle contraction are located on the ________________.
a)
myosin filaments
b)
actin filaments
c)
tropomyosin
d)
troponin
5.
Which of these statements is correct regarding muscle contraction?
a)
All motor units act together
b)
Muscle contraction continues for long periods after nervous stimulation ceases
c)
The crossbridges bind to the actin and shorten the sarcomeres
d)
Troponin is not needed to strengthen the contracting muscle cell.
6.
Each muscle fiber is directly surrounded by connective tissue called the
a)
perimysium
b)
fascia
c)
endomysium
d)
epimysium
7.
Which of the following is not a component of a thin filament?
a)
actin
b)
myosin
c)
troponin
d)
tropomyosin
8.
Which of the following statements concerning the role of Ca2+ in the contraction of skeletal muscle is correct?
a)
The mitochondria act as a store of Ca2+ for the contractile process
b)
Ca2+ entry across the plasma membrane is important in sustaining the contraction of skeletal muscle
c)
A rise in intracellular Ca2+allows actin to interact with myosin
d)
The tension of a skeletal muscle fibre is partly regulated by G proteins.
9.
The functional unit of the contractile system in skeletal muscle is(are)
a)
myofibrils
b)
cross-bridges
c)
sarcomeres
d)
Z-bands
10.
Muscle fatigue sets in due to the nonavailability of
a)
calcium
b)
ATP
c)
actin binding sites
d)
sodium
11.
Which of the following sets of ions are necessary in the chemical events of muscle contraction?
a)
sodium and potassium
b)
calcium and magnesium
c)
sodium and calcium
d)
sodium and magnesium
12.
The neurotransmitter always used at the neuromuscular junction is:
a)
It depends upon the type of muscle being innervated
b)
noradrenaline
c)
acetylcholine
d)
dopamine
13.
A long chain of globular actin forms
a)
troponin
b)
tropomyosin
c)
F-actin
d)
G-actin
14.
Which of the following steps occurs last in this series?
a)
Calcium enters the neuron and attaches to synaptic vesicles that carry acetylcholine
b)
sodium enters and an action potential occurs across the muscle
c)
calcium attaches to troponin and causes a change in the shape of the tropomyosin
d)
the active site of troponin are exposed
15.
Which of the following steps occurs first?
a)
myosin heads attach to actin
b)
myosin heads pivot pulling the actin filament toward the center
c)
cross-bridges detach from actin when a new ATP binds to myosin
d)
another cross-bridge forms
16.
Which of the following occurs when a muscle contracts?
a)
the distance between z-lines decreases
b)
the H-zone disappears
c)
the muscle shortens
d)
the distance between z-lines decreases, the H-zone disappears, and the muscle shortens
17.
The first thing to occur after a muscle contraction is the breakdown of acetylcholine by cholinesterase.
a)
True
b)
False
18.
Rigor mortis sets in when there is no calcium to bind to troponin.
a)
True
b)
False
100 %
