EXPH 386 Exam 3-Questions And
Correct Solutions Set-2026
coordination and integration of the muscles of the body together with the
nerves that supply them - Ans--Neuromuscular system
Cell body (soma) action - Ans--dictates the critical firing rate of the action
potential
Cell body (soma) contains what - Ans--structures involved in replication and
transmission of the genetic code
Are larger cell bodies (somas) associated with higher or lower critical firing
rates? - Ans--higher
short neural branches that receive impulses through numerous
connections and conduct them toward the cell body - Ans--Dendrites
extends from the cell body to deliver action potentials toward the muscle to
the motor endplate - Ans--Axon
Are larger axons associated with slower or faster conduction velocities? -
Ans--faster
a lipoprotein membrane that wraps around the axon over most of its length -
Ans--Myelin sheath
What does the myelin sheath act as? - Ans--an electrical insulator that
envelops the axon similar to the plastic coating around an electrical wire
specialized cells that create or deposit myelin sheath around the axon -
Ans--schwann cells
structures that interrupt the myelin sheath every 1 to 2 mm along the length
of the axon - Ans--nodes of ranvier
,what do the nodes of ranvier allow? - Ans--they allow the action potential to
jump from node to node covering a larger distance, increasing the speed of
the action potential
when the action potential jumps from node to node because of the
uninsulated gaps - Ans--saltory conduction
What would happen if no myelin were present? - Ans--conduction velocities
would be a lot slower since the action potential would have to be conducted
along the entire length of the axon
multiple extensions of the axon that innervate individual muscle fibers -
Ans--nerve terminal branches
True or False. any one muscle fiber is only going to receive innervation from
one nerve terminal branch - Ans--true
represents the interface between the end of the axon at the terminal branch
and the muscle fiber - Ans--Motor endplate or neuromuscular junction
Break down of skeletal muscle from biggest to smallest (6) - Ans--1. whole
muscle
2. bundle of fibers
3. single fiber
4. myofibrils
5. sarcomere
6. contractile proteins
what are the skeletal muscles of the body composed of? - Ans--multi-
nucleated cylindrical cells called fibers which run parallel to eachother
Force is directed along what? - Ans--the fiber's long axis
fiber length variation - Ans--few millimeters (eye) to approx. 30 cm (leg)
what are the connective tissue layers associated with skeletal muscle? -
Ans--Endomysium
,Perimysium
Fasiculus
Epimysium
Tendons
Periosteum
a fine layer of connective tissue that wraps each muscle fiber and separates
it from the neighboring fibers - Ans--Endomysium
surrounds a bundle of up to 150 fibers - Ans--Perimysium
a large bundle of fibers - Ans--fasiculus
a fascia of fibrous connective tissue that surrounds the entire muscle - Ans--
epimysium
dense connective tissue, the extension of the epimysium at the ends of the
muscle - Ans--tendons
bone's outermost covering; tendons connect the muscle to this covering of
the bone - Ans--periosteum
The 4 skeletal muscle structures - Ans--sarcolemma
basement membrane
sarcoplasm
sarcoplasmic reticulum
the muscle fiber membrane; a thin elastic membrane that encloses the
fiber's cellular contents - Ans--Sarcolemma
What is the true fiber boundary? - Ans--the sarcolemma
a loose collection of glycoproteins and collagen; outside the muscle fiber -
Ans--Basement membrane
contains the nuclei, substrates, and enzymes required for metabolism, the
nuclei, mitochondria, and other specialized organelles - Ans--Sarcoplasm
, highly specialized network of tubular channels - Ans--sarcoplasmic
reticulum
What does the sarcoplasmic reticulum allow for? - Ans--a wave of
depolarization to spread rapidly from the sarcolemma to the inner
environment through the T-Tubules to initiate muscle contraction
What does the sarcoplasmic reticulum store? - Ans--a large concentration
of calcium in the muscle fiber
true muscle fiber nuclei - Ans--Myonuclei
Where do myonuclei reside? - Ans--directly under the sarcolemma at the
periphery of the fiber
Myonuclei represent how much of the total nuclear pool? - Ans--85 to 95%
Explain the myonuclear domain hypothesis - Ans--
normally dormant myoblasts that lie between the basement membrane and
the sarcolemma - Ans--satellite cells
upon activation, this cell's functions include muscle regeneration, muscle
growth, exercise-induced adaptations, and recovery from injury - Ans--
satellite cells
the location where the tendon joins a relatively stable skeletal part,
generally the proximal end of the muscle - Ans--muscle origin
the location where the tendon joins a movable skeletal part, generally the
distal end of the muscle - Ans--muscle insertion
Describe what happens during muscle action - Ans--the force of muscle
action transmits directly from the connective tissue, harness to the tendons,
which then pull on the bone at the point of attachment
Correct Solutions Set-2026
coordination and integration of the muscles of the body together with the
nerves that supply them - Ans--Neuromuscular system
Cell body (soma) action - Ans--dictates the critical firing rate of the action
potential
Cell body (soma) contains what - Ans--structures involved in replication and
transmission of the genetic code
Are larger cell bodies (somas) associated with higher or lower critical firing
rates? - Ans--higher
short neural branches that receive impulses through numerous
connections and conduct them toward the cell body - Ans--Dendrites
extends from the cell body to deliver action potentials toward the muscle to
the motor endplate - Ans--Axon
Are larger axons associated with slower or faster conduction velocities? -
Ans--faster
a lipoprotein membrane that wraps around the axon over most of its length -
Ans--Myelin sheath
What does the myelin sheath act as? - Ans--an electrical insulator that
envelops the axon similar to the plastic coating around an electrical wire
specialized cells that create or deposit myelin sheath around the axon -
Ans--schwann cells
structures that interrupt the myelin sheath every 1 to 2 mm along the length
of the axon - Ans--nodes of ranvier
,what do the nodes of ranvier allow? - Ans--they allow the action potential to
jump from node to node covering a larger distance, increasing the speed of
the action potential
when the action potential jumps from node to node because of the
uninsulated gaps - Ans--saltory conduction
What would happen if no myelin were present? - Ans--conduction velocities
would be a lot slower since the action potential would have to be conducted
along the entire length of the axon
multiple extensions of the axon that innervate individual muscle fibers -
Ans--nerve terminal branches
True or False. any one muscle fiber is only going to receive innervation from
one nerve terminal branch - Ans--true
represents the interface between the end of the axon at the terminal branch
and the muscle fiber - Ans--Motor endplate or neuromuscular junction
Break down of skeletal muscle from biggest to smallest (6) - Ans--1. whole
muscle
2. bundle of fibers
3. single fiber
4. myofibrils
5. sarcomere
6. contractile proteins
what are the skeletal muscles of the body composed of? - Ans--multi-
nucleated cylindrical cells called fibers which run parallel to eachother
Force is directed along what? - Ans--the fiber's long axis
fiber length variation - Ans--few millimeters (eye) to approx. 30 cm (leg)
what are the connective tissue layers associated with skeletal muscle? -
Ans--Endomysium
,Perimysium
Fasiculus
Epimysium
Tendons
Periosteum
a fine layer of connective tissue that wraps each muscle fiber and separates
it from the neighboring fibers - Ans--Endomysium
surrounds a bundle of up to 150 fibers - Ans--Perimysium
a large bundle of fibers - Ans--fasiculus
a fascia of fibrous connective tissue that surrounds the entire muscle - Ans--
epimysium
dense connective tissue, the extension of the epimysium at the ends of the
muscle - Ans--tendons
bone's outermost covering; tendons connect the muscle to this covering of
the bone - Ans--periosteum
The 4 skeletal muscle structures - Ans--sarcolemma
basement membrane
sarcoplasm
sarcoplasmic reticulum
the muscle fiber membrane; a thin elastic membrane that encloses the
fiber's cellular contents - Ans--Sarcolemma
What is the true fiber boundary? - Ans--the sarcolemma
a loose collection of glycoproteins and collagen; outside the muscle fiber -
Ans--Basement membrane
contains the nuclei, substrates, and enzymes required for metabolism, the
nuclei, mitochondria, and other specialized organelles - Ans--Sarcoplasm
, highly specialized network of tubular channels - Ans--sarcoplasmic
reticulum
What does the sarcoplasmic reticulum allow for? - Ans--a wave of
depolarization to spread rapidly from the sarcolemma to the inner
environment through the T-Tubules to initiate muscle contraction
What does the sarcoplasmic reticulum store? - Ans--a large concentration
of calcium in the muscle fiber
true muscle fiber nuclei - Ans--Myonuclei
Where do myonuclei reside? - Ans--directly under the sarcolemma at the
periphery of the fiber
Myonuclei represent how much of the total nuclear pool? - Ans--85 to 95%
Explain the myonuclear domain hypothesis - Ans--
normally dormant myoblasts that lie between the basement membrane and
the sarcolemma - Ans--satellite cells
upon activation, this cell's functions include muscle regeneration, muscle
growth, exercise-induced adaptations, and recovery from injury - Ans--
satellite cells
the location where the tendon joins a relatively stable skeletal part,
generally the proximal end of the muscle - Ans--muscle origin
the location where the tendon joins a movable skeletal part, generally the
distal end of the muscle - Ans--muscle insertion
Describe what happens during muscle action - Ans--the force of muscle
action transmits directly from the connective tissue, harness to the tendons,
which then pull on the bone at the point of attachment
