KINE 433 Muscle questions with verified answers
What muscle is internal organs? What do the blood vessels allow in them? Ans✓✓
-smooth muscle (involuntary)
contract/relax
Which muscle types are striated? Ans✓✓ -skeletal and cardiac
Which muscle is under parasympathetic and sypathetic influence? Ans✓✓ -
cardiac muscle
What does skeletal muscle make up Ans✓✓ -skeleton and muscle
Muscle is made up of Ans✓✓ -bundles (fasciculi)
Several individual muscle fibers enclosed in perimysium tissue Ans✓✓ -fascicule
Muscle cell with myofibrils divided into sarcomeres Ans✓✓ -fiber
How many fibers in muscles Ans✓✓ -100s to millions, 12 cm thick
Plasmalemma Ans✓✓ -plasma membrane
conducts action potential
maintains pH, transports nutrients
Cells btwn plasmalemma and basement membrane
muscle growth/development
response to injury, immobilization, training Ans✓✓ -satellite cells
Sarcoplasm Ans✓✓ -fluid part of the fiber, fills space btwn it
transverse t tubules Ans✓✓ -take AP down deep
connect interior to exterior help remove waste and deliver nutrients
extensions of plasmalemma
Sarcoplasmic Reticulum Ans✓✓ -network of tubules that surrounds the myofibrils
stores Calcium
What stores calcium? Ans✓✓ -sarcoplasmic reticulum
****What is the functional unit of the myofibril? Ans✓✓ -sarcomere
, Sarcomere Ans✓✓ -functional unit of myofibril
contractile unit of skeletal muscle
end to end myofibril length
A band vs I band Ans✓✓ -A band: actin+ myosin (dark)
I band: actin (light)
Actin vs myosin Ans✓✓ -actin: light, thin, on I band
myosin: dark, thick, on H band and A band
H zone Ans✓✓ -has myosin only
Myosin structure Ans✓✓ -2 intertwined filaments + globular heads
stabilized by titin
globular heads protrude 360 degrees from thick filament axis
Structure of Actin Ans✓✓ -3 globular proteins (troponin, tropomyosin, myosin
binding site composed of helix of globular proteins (G-actin)
What innervates muscle fibers? Ans✓✓ -alpha motor neurons
Neuromuscular junction synapse btwn Ans✓✓ -alpha motor neuron and muscle
fiber
Excitation contraction coupling Ans✓✓ -1. AP starts in brain
2. AP arrives at axon terminal & releases ACh
3. ACh crosses synapse, binds to ACh receptors on plamalemma
4. ACh travels down plasmalemma, T-tubules
5. Triggers Ca2+ release from SR
6. Ca2+ enables actin-myosin contraction
Calcium binds to Ans✓✓ -troponin on the thin filament
At rest __________ covers myosin-binding site, blocking actin-myosin attraction.
Ans✓✓ -tropomyosin
Troponin function Ans✓✓ -Ca2+ attaches to troponin and moves tropomyosin out
of the way
What muscle is internal organs? What do the blood vessels allow in them? Ans✓✓
-smooth muscle (involuntary)
contract/relax
Which muscle types are striated? Ans✓✓ -skeletal and cardiac
Which muscle is under parasympathetic and sypathetic influence? Ans✓✓ -
cardiac muscle
What does skeletal muscle make up Ans✓✓ -skeleton and muscle
Muscle is made up of Ans✓✓ -bundles (fasciculi)
Several individual muscle fibers enclosed in perimysium tissue Ans✓✓ -fascicule
Muscle cell with myofibrils divided into sarcomeres Ans✓✓ -fiber
How many fibers in muscles Ans✓✓ -100s to millions, 12 cm thick
Plasmalemma Ans✓✓ -plasma membrane
conducts action potential
maintains pH, transports nutrients
Cells btwn plasmalemma and basement membrane
muscle growth/development
response to injury, immobilization, training Ans✓✓ -satellite cells
Sarcoplasm Ans✓✓ -fluid part of the fiber, fills space btwn it
transverse t tubules Ans✓✓ -take AP down deep
connect interior to exterior help remove waste and deliver nutrients
extensions of plasmalemma
Sarcoplasmic Reticulum Ans✓✓ -network of tubules that surrounds the myofibrils
stores Calcium
What stores calcium? Ans✓✓ -sarcoplasmic reticulum
****What is the functional unit of the myofibril? Ans✓✓ -sarcomere
, Sarcomere Ans✓✓ -functional unit of myofibril
contractile unit of skeletal muscle
end to end myofibril length
A band vs I band Ans✓✓ -A band: actin+ myosin (dark)
I band: actin (light)
Actin vs myosin Ans✓✓ -actin: light, thin, on I band
myosin: dark, thick, on H band and A band
H zone Ans✓✓ -has myosin only
Myosin structure Ans✓✓ -2 intertwined filaments + globular heads
stabilized by titin
globular heads protrude 360 degrees from thick filament axis
Structure of Actin Ans✓✓ -3 globular proteins (troponin, tropomyosin, myosin
binding site composed of helix of globular proteins (G-actin)
What innervates muscle fibers? Ans✓✓ -alpha motor neurons
Neuromuscular junction synapse btwn Ans✓✓ -alpha motor neuron and muscle
fiber
Excitation contraction coupling Ans✓✓ -1. AP starts in brain
2. AP arrives at axon terminal & releases ACh
3. ACh crosses synapse, binds to ACh receptors on plamalemma
4. ACh travels down plasmalemma, T-tubules
5. Triggers Ca2+ release from SR
6. Ca2+ enables actin-myosin contraction
Calcium binds to Ans✓✓ -troponin on the thin filament
At rest __________ covers myosin-binding site, blocking actin-myosin attraction.
Ans✓✓ -tropomyosin
Troponin function Ans✓✓ -Ca2+ attaches to troponin and moves tropomyosin out
of the way
