ANP1105 EXAM QUESTIONS WITH 100%
CORRECT ANSWERS | LATEST
VERSION 2025/2026.
Afferent neurons - ANS Aka sensory neutrons, they bring stimuli from the sensors
(skin,eyes,ears ect) to the CNS
Efferent neurons - ANS Aka motor neurons, they bring the responses from the brain to the
muscles and the glands
The overlapping functions of the nervous system are sensory input,integration and motor
output. True or false? - ANS True
Which neurological cell is the most abundant in the CNS? - ANS Astrocytes
What is the function of astrocytes within the CNS? - ANS They support neurons and anchor
them to their nutrient source
What is the function of oligodendrocytes? - ANS They form myelin sheaths working the white
matter of the CNS
What is the neuromuscular junction? - ANS The neuromuscular junction is a chemical
synapse. An electrical signal (known as an action potential) from the motor neuron is converted
into a chemical signal (ACh release). The skeletal muscle fiber responds to the chemical signal
(ACh) by depolarizing and initiating an action potential. This action potential is propagated
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,along the sarcolemma of the muscle fiber, which triggers sliding of the myofilaments for muscle
contraction.
Excitation-contraction coupling is a series of events that occur after the events of the
neuromuscular junction have transpired. The term excitation refers to which step in the
process? - ANS Excitation, in this case, refers to the propagation of action potentials along
the sarcolemma.
Excitation of the sarcolemma is coupled or linked to the contraction of a skeletal muscle fiber.
What specific event initiates the contraction? - ANS Calcium release from the sarcoplasmic
reticulum initiates the contraction.
A triad is composed of a T-tubule and two adjacent terminal cisternae of the sarcoplasmic
reticulum. How are these components connected? - ANS A series of proteins that control
calcium release
What is the Sarcoplasmic reticulum? - ANS Sarcoplasmic reticulum is the specific name given
to the smooth endoplasmic reticulum in muscle cells. It is especially abundant and convoluted
in skeletal muscle cells. It functions in the storage, release, and reuptake of calcium ions.
What is name given to the regularly spaced infoldings of the sarcolemma? - ANS transverse
or T tubules
What is most directly responsible for the coupling of excitation to contraction of skeletal muscle
fibers? - ANS Calcium ions.
Action potentials propagating down the T-tubule cause a voltage-sensitive protein to change
shape. This shape change opens calcium release channels in the sarcoplasmic reticulum,
allowing calcium ions to flood the sarcoplasm. This flood of calcium ions is directly responsible
for the coupling of excitation to contraction in skeletal muscle fibers.
What is the relationship between the number of motor neurons recruited and the number of
skeletal muscle fibers innervated? - ANS Typically, hundreds of skeletal muscle fibers are
innervated by a single motor neuron.
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, The cross bridge cycle is a series of molecular events that occur after excitation of the
sarcolemma. What is a cross bridge? - ANS A myosin head bound to actin.
What structure is the functional unit of contraction in a skeletal muscle fiber? - ANS The
sarcomere
What is a sarcomere? - ANS A sarcomere is a regular arrangement of thin and thick
myofilaments that extends from one Z disc to the next. A myofibril consists of a series of
sarcomeres.
(The Cross Bridge cycle)
Calcium ions couple excitation of a skeletal muscle fiber to contraction of the fiber. Where are
calcium ions stored within the fiber? - ANS Calcium ions are stored in the sarcoplasmic
reticulum
(The Cross Bridge cycle)
After a power stroke, the myosin head must detach from actin before another power stroke
can occur. What causes cross bridge detachment?
After a power stroke, the myosin head must detach from actin before another power stroke
can occur. What causes cross bridge detachment? - ANS ATP binds to the myosin head. The
binding of ATP to the myosin head weakens the bond between myosin and actin, forcing the
myosin head to detach. ATP also provides the energy for the next power stroke.
Steps of the Cross Bridge cycle. - ANS 1) Cross bridge formation: The activated myosin head
binds to actin forming a cross bridge. Inorganic phosphate is released. Bond between actin and
myosin becomes stronger.
2)The power stroke: ADP is released and the activated myosin head pivots, sliding the thin
myofilament towards the sarcomere.
3) Cross bridge detachment: When another ATP binds to the myosin head the link between the
myosin head and actin weakens and the myosin head detaches.
4) Reactivation of the myosin head: ATP is hydrolyzed to ADP and inorganic phosphate. The
energy released during hydrolysis reactivates the myosin head, returning it to the cocked
position.
3 | Page @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
CORRECT ANSWERS | LATEST
VERSION 2025/2026.
Afferent neurons - ANS Aka sensory neutrons, they bring stimuli from the sensors
(skin,eyes,ears ect) to the CNS
Efferent neurons - ANS Aka motor neurons, they bring the responses from the brain to the
muscles and the glands
The overlapping functions of the nervous system are sensory input,integration and motor
output. True or false? - ANS True
Which neurological cell is the most abundant in the CNS? - ANS Astrocytes
What is the function of astrocytes within the CNS? - ANS They support neurons and anchor
them to their nutrient source
What is the function of oligodendrocytes? - ANS They form myelin sheaths working the white
matter of the CNS
What is the neuromuscular junction? - ANS The neuromuscular junction is a chemical
synapse. An electrical signal (known as an action potential) from the motor neuron is converted
into a chemical signal (ACh release). The skeletal muscle fiber responds to the chemical signal
(ACh) by depolarizing and initiating an action potential. This action potential is propagated
1 | Page @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
,along the sarcolemma of the muscle fiber, which triggers sliding of the myofilaments for muscle
contraction.
Excitation-contraction coupling is a series of events that occur after the events of the
neuromuscular junction have transpired. The term excitation refers to which step in the
process? - ANS Excitation, in this case, refers to the propagation of action potentials along
the sarcolemma.
Excitation of the sarcolemma is coupled or linked to the contraction of a skeletal muscle fiber.
What specific event initiates the contraction? - ANS Calcium release from the sarcoplasmic
reticulum initiates the contraction.
A triad is composed of a T-tubule and two adjacent terminal cisternae of the sarcoplasmic
reticulum. How are these components connected? - ANS A series of proteins that control
calcium release
What is the Sarcoplasmic reticulum? - ANS Sarcoplasmic reticulum is the specific name given
to the smooth endoplasmic reticulum in muscle cells. It is especially abundant and convoluted
in skeletal muscle cells. It functions in the storage, release, and reuptake of calcium ions.
What is name given to the regularly spaced infoldings of the sarcolemma? - ANS transverse
or T tubules
What is most directly responsible for the coupling of excitation to contraction of skeletal muscle
fibers? - ANS Calcium ions.
Action potentials propagating down the T-tubule cause a voltage-sensitive protein to change
shape. This shape change opens calcium release channels in the sarcoplasmic reticulum,
allowing calcium ions to flood the sarcoplasm. This flood of calcium ions is directly responsible
for the coupling of excitation to contraction in skeletal muscle fibers.
What is the relationship between the number of motor neurons recruited and the number of
skeletal muscle fibers innervated? - ANS Typically, hundreds of skeletal muscle fibers are
innervated by a single motor neuron.
2 | Page @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, The cross bridge cycle is a series of molecular events that occur after excitation of the
sarcolemma. What is a cross bridge? - ANS A myosin head bound to actin.
What structure is the functional unit of contraction in a skeletal muscle fiber? - ANS The
sarcomere
What is a sarcomere? - ANS A sarcomere is a regular arrangement of thin and thick
myofilaments that extends from one Z disc to the next. A myofibril consists of a series of
sarcomeres.
(The Cross Bridge cycle)
Calcium ions couple excitation of a skeletal muscle fiber to contraction of the fiber. Where are
calcium ions stored within the fiber? - ANS Calcium ions are stored in the sarcoplasmic
reticulum
(The Cross Bridge cycle)
After a power stroke, the myosin head must detach from actin before another power stroke
can occur. What causes cross bridge detachment?
After a power stroke, the myosin head must detach from actin before another power stroke
can occur. What causes cross bridge detachment? - ANS ATP binds to the myosin head. The
binding of ATP to the myosin head weakens the bond between myosin and actin, forcing the
myosin head to detach. ATP also provides the energy for the next power stroke.
Steps of the Cross Bridge cycle. - ANS 1) Cross bridge formation: The activated myosin head
binds to actin forming a cross bridge. Inorganic phosphate is released. Bond between actin and
myosin becomes stronger.
2)The power stroke: ADP is released and the activated myosin head pivots, sliding the thin
myofilament towards the sarcomere.
3) Cross bridge detachment: When another ATP binds to the myosin head the link between the
myosin head and actin weakens and the myosin head detaches.
4) Reactivation of the myosin head: ATP is hydrolyzed to ADP and inorganic phosphate. The
energy released during hydrolysis reactivates the myosin head, returning it to the cocked
position.
3 | Page @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
