Kine 433 Exam 2 2026 (Actual Exam) Questions with verified Answers (Latest
Update 2026) UPDATE!!
Skeletal muscle characteristics - (ANSWER)voluntary, regulated by CNS
what is epimysium? - (ANSWER)connective tissue that surrounds entire muscle
what is endomysium? - (ANSWER)connective tissue around individual muscle fibers
what is perimysium? - (ANSWER)connective tissue around bundles of muscle fibers
what is fasciculus? - (ANSWER)bundle of muscle fibers
what is myofibril? - (ANSWER)contractile element inside muscle fiber composed of actin and myosin
what is plasmalemma? - (ANSWER)membrane surrounding muscle fiber that conducts/propagates action
potential
are muscle fibers single or multinucleated? why? - (ANSWER)multinucleated because muscle fibers are
large cells that developed from fusion of many myoblasts, all which had their own nucleus
what are T tubules? - (ANSWER)components of the plasmalemma that run deep into the muscle fiber to
propagate electrical signals
what is sarcomere? - (ANSWER)contractile unit of muscle fiber
what are thick filaments of sarcomere composed of? - (ANSWER)myosin
what are thin filaments of sarcomere composed of? - (ANSWER)actin, tropomyosin, and troponin
what makes up the I band? - (ANSWER)actin
, Kine 433 Exam 2 2026 (Actual Exam) Questions with verified Answers (Latest
Update 2026) UPDATE!!
what makes up the A band? - (ANSWER)The A band spans the entire length of the thick filament
(myosin). Therefore, it includes both the overlap regions where actin and myosin are present together
and the H zone, where only myosin is present.
how does signal (action potential) get from central command to muscle? - (ANSWER)alpha motor neuron
what is motor unit? - (ANSWER)alpha motor nerve and all the muscles it innervates
what blocks the active site at rest? - (ANSWER)tropomyosin
what is bound to the myosin at rest? - (ANSWER)ATP
what does myosin ATPase do when muscle goes from relaxed to contracting? - (ANSWER)hydrolyzes the
ATP into ADP and Pi (phosphate group)
what causes active site to become exposed? - (ANSWER)calcium binds to troponin which pulls
tropomyosin away from active site
what is the power stroke? - (ANSWER)when Pi is released and myosin head pulls actin to produce force.
Power stroke ends when ADP is released
what allows myosin head to release from actin? - (ANSWER)new ATP binds to myosin head
how does contraction stop? - (ANSWER)CC stops intent to exercise, acetylcholine in NMJ degraded,
calcium pumped back into sarcoplasmic reticulum
what are type I fibers? - (ANSWER)slow twitch with high oxidative capacity
Update 2026) UPDATE!!
Skeletal muscle characteristics - (ANSWER)voluntary, regulated by CNS
what is epimysium? - (ANSWER)connective tissue that surrounds entire muscle
what is endomysium? - (ANSWER)connective tissue around individual muscle fibers
what is perimysium? - (ANSWER)connective tissue around bundles of muscle fibers
what is fasciculus? - (ANSWER)bundle of muscle fibers
what is myofibril? - (ANSWER)contractile element inside muscle fiber composed of actin and myosin
what is plasmalemma? - (ANSWER)membrane surrounding muscle fiber that conducts/propagates action
potential
are muscle fibers single or multinucleated? why? - (ANSWER)multinucleated because muscle fibers are
large cells that developed from fusion of many myoblasts, all which had their own nucleus
what are T tubules? - (ANSWER)components of the plasmalemma that run deep into the muscle fiber to
propagate electrical signals
what is sarcomere? - (ANSWER)contractile unit of muscle fiber
what are thick filaments of sarcomere composed of? - (ANSWER)myosin
what are thin filaments of sarcomere composed of? - (ANSWER)actin, tropomyosin, and troponin
what makes up the I band? - (ANSWER)actin
, Kine 433 Exam 2 2026 (Actual Exam) Questions with verified Answers (Latest
Update 2026) UPDATE!!
what makes up the A band? - (ANSWER)The A band spans the entire length of the thick filament
(myosin). Therefore, it includes both the overlap regions where actin and myosin are present together
and the H zone, where only myosin is present.
how does signal (action potential) get from central command to muscle? - (ANSWER)alpha motor neuron
what is motor unit? - (ANSWER)alpha motor nerve and all the muscles it innervates
what blocks the active site at rest? - (ANSWER)tropomyosin
what is bound to the myosin at rest? - (ANSWER)ATP
what does myosin ATPase do when muscle goes from relaxed to contracting? - (ANSWER)hydrolyzes the
ATP into ADP and Pi (phosphate group)
what causes active site to become exposed? - (ANSWER)calcium binds to troponin which pulls
tropomyosin away from active site
what is the power stroke? - (ANSWER)when Pi is released and myosin head pulls actin to produce force.
Power stroke ends when ADP is released
what allows myosin head to release from actin? - (ANSWER)new ATP binds to myosin head
how does contraction stop? - (ANSWER)CC stops intent to exercise, acetylcholine in NMJ degraded,
calcium pumped back into sarcoplasmic reticulum
what are type I fibers? - (ANSWER)slow twitch with high oxidative capacity
