BIOL460 EXAM 4 QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
True or False: Skeletal muscles with a low innervation ratio have a low degree of
neural control, i.e. they are not very precise.
False
________ ___________ is characterized by continued attachment of myosin cross
bridge heads to actin filaments due to a lack of ATP.
rigor mortis
What structures carry the action potentials into the interior of the muscle to
cause muscle contraction?
T tubules
Check out the microscope image below. The labeled area X is referring to the
_____ _____. (A band)
A band
True or False: Transverse tubules contain voltage-gated calcium channels that
respond to membrane depolarization and are directly coupled to the calcium
release channels in the sarcoplasmic reticulum.
True
Which of the following is needed for the myosin cross bridge head to undergo a
power stroke?
release of phosphate
, You take a biopsy of a skeletal muscle to determine what type of fibers make up
this particular motor unit. The fibers in your sample are red in color, they have
many mitochondria, and a good bit of myoglobin, yet the diameter of the fibers
appears to be quite small. Of the two fiber types, you have just identified _____
fibers.
oxidative
In regards to the relationship between resting muscle fiber length and tension
generated, maximal tension can be generated when:
thick and thin filaments overlap
In order for skeletal muscles to contract, Ca2+ must bind to _____ in order to
move the _____ out of the myosin binding domain of the G actin molecules.
troponin; tropomyosin
What is the role of ATP in muscle contraction and relaxation?
-It powers the Ca2+ pumps to return Ca2+ to the sarcoplasmic reticulum.
-It is hydrolyzed by the myosin cross bridge head prior to cross bridge
attachment.
-It causes the myosin cross bridge head to detach from actin after the power
stroke.
-all of the above
All of the above
The majority of the Ca2+ required for skeletal muscle contraction comes from the
_____ _____.
sarcoplasmic reticulum
COMPLETE SOLUTIONS VERIFIED
True or False: Skeletal muscles with a low innervation ratio have a low degree of
neural control, i.e. they are not very precise.
False
________ ___________ is characterized by continued attachment of myosin cross
bridge heads to actin filaments due to a lack of ATP.
rigor mortis
What structures carry the action potentials into the interior of the muscle to
cause muscle contraction?
T tubules
Check out the microscope image below. The labeled area X is referring to the
_____ _____. (A band)
A band
True or False: Transverse tubules contain voltage-gated calcium channels that
respond to membrane depolarization and are directly coupled to the calcium
release channels in the sarcoplasmic reticulum.
True
Which of the following is needed for the myosin cross bridge head to undergo a
power stroke?
release of phosphate
, You take a biopsy of a skeletal muscle to determine what type of fibers make up
this particular motor unit. The fibers in your sample are red in color, they have
many mitochondria, and a good bit of myoglobin, yet the diameter of the fibers
appears to be quite small. Of the two fiber types, you have just identified _____
fibers.
oxidative
In regards to the relationship between resting muscle fiber length and tension
generated, maximal tension can be generated when:
thick and thin filaments overlap
In order for skeletal muscles to contract, Ca2+ must bind to _____ in order to
move the _____ out of the myosin binding domain of the G actin molecules.
troponin; tropomyosin
What is the role of ATP in muscle contraction and relaxation?
-It powers the Ca2+ pumps to return Ca2+ to the sarcoplasmic reticulum.
-It is hydrolyzed by the myosin cross bridge head prior to cross bridge
attachment.
-It causes the myosin cross bridge head to detach from actin after the power
stroke.
-all of the above
All of the above
The majority of the Ca2+ required for skeletal muscle contraction comes from the
_____ _____.
sarcoplasmic reticulum
