KINE 433 Exam 2 questions with verified answers
Epimysium Ans✓✓ -outer layer surrounding the muscle belly
fasciculi Ans✓✓ -several individual muscle fibers enclosed in perimysium tissue
Perimysium Ans✓✓ -Connective tissue surrounding a fascicle
Muscle fiber Ans✓✓ -muscle cell w/ myofibrils divided into sarcomeres
Where are satellite cells found? Ans✓✓ -Between plasmalemma & basement
membrane
What do satellite cells do? Ans✓✓ -Muscle growth, development
--> response to injury, immobilization, training
What are the 2 "sugar tanks" where glycogen is stored? Ans✓✓ -muscle and liver
Sarcoplasmic Reticulum Ans✓✓ -Longitudinal network of tubules surrounding
myofibrils
--> Ca+ storage necessary for contraction
Sarcomeres Ans✓✓ -Basic contractile element of skeletal muscle contraction
What causes the distinctive striped appearance (striations)? Ans✓✓ -overlapping
of actin & myosin
-->Actin= thin, light myofilament
,--> Myosin= thick, dark myofilament
What does Ca+ bind to? Ans✓✓ -troponin
Motor unit Ans✓✓ -single alpha-motor neuron and all fibers it innervates
--> More operating motor units= more contractile force
--> think of force production when thinking about # of fibers innervated
Dendrites Ans✓✓ -finger-like projections that receive AP and deliver to cell body
What has the greatest sodium density in the motor unit? Ans✓✓ -Axon hillock
Neuromuscular Junction (NMJ) Ans✓✓ -Communication site between neuron &
muscle
--> Consists of synapse between a-motor neuron & muscle fiber
Steps for Skeletal muscle contraction Ans✓✓ -1. AP starts in brain
2. AP arrives at axon terminal, releases ACh
3. Acetylcholine crosses synapse, binds to ACh receptors on plasmalemma
4. AP travels down plasmalemma, T-tubules
5. Triggers Ca+ release from SR
6. Ca+ enables actin-myosin contraction
What is the I band composed of? Ans✓✓ -Compromised only of actin (light)
--> myosin end to myosin end
, What is the H zone composed of? Ans✓✓ -only myosin section
--> goes away during maximal contraction
What is the A band composed of? Ans✓✓ -actin and myosin
What is Myosin-ATPase? Ans✓✓ -an enzyme located in the myosin head that
hydrolyzes ATP
What is the importance of ATP in muscular contraction? Ans✓✓ -important for
bringing Ca+ back to SR
T or F: Muscular relaxation requires ATP. Ans✓✓ -True
What size neuron do type I fibers have? Ans✓✓ -small sized
--> <300 fibers
What size neuron do type II fibers have? Ans✓✓ -large sized
---> >300 fibers
T or F: Type I and II fibers with the same diameter will distribute the same
amounts of force. Ans✓✓ -True
T or F: Fibers w/ same diameter will distribute the same amounts of power
Ans✓✓ -False
--> Type II fibers= more power
Muscle fiber peak power order Ans✓✓ -Type IIx> Type IIa> Type I
Epimysium Ans✓✓ -outer layer surrounding the muscle belly
fasciculi Ans✓✓ -several individual muscle fibers enclosed in perimysium tissue
Perimysium Ans✓✓ -Connective tissue surrounding a fascicle
Muscle fiber Ans✓✓ -muscle cell w/ myofibrils divided into sarcomeres
Where are satellite cells found? Ans✓✓ -Between plasmalemma & basement
membrane
What do satellite cells do? Ans✓✓ -Muscle growth, development
--> response to injury, immobilization, training
What are the 2 "sugar tanks" where glycogen is stored? Ans✓✓ -muscle and liver
Sarcoplasmic Reticulum Ans✓✓ -Longitudinal network of tubules surrounding
myofibrils
--> Ca+ storage necessary for contraction
Sarcomeres Ans✓✓ -Basic contractile element of skeletal muscle contraction
What causes the distinctive striped appearance (striations)? Ans✓✓ -overlapping
of actin & myosin
-->Actin= thin, light myofilament
,--> Myosin= thick, dark myofilament
What does Ca+ bind to? Ans✓✓ -troponin
Motor unit Ans✓✓ -single alpha-motor neuron and all fibers it innervates
--> More operating motor units= more contractile force
--> think of force production when thinking about # of fibers innervated
Dendrites Ans✓✓ -finger-like projections that receive AP and deliver to cell body
What has the greatest sodium density in the motor unit? Ans✓✓ -Axon hillock
Neuromuscular Junction (NMJ) Ans✓✓ -Communication site between neuron &
muscle
--> Consists of synapse between a-motor neuron & muscle fiber
Steps for Skeletal muscle contraction Ans✓✓ -1. AP starts in brain
2. AP arrives at axon terminal, releases ACh
3. Acetylcholine crosses synapse, binds to ACh receptors on plasmalemma
4. AP travels down plasmalemma, T-tubules
5. Triggers Ca+ release from SR
6. Ca+ enables actin-myosin contraction
What is the I band composed of? Ans✓✓ -Compromised only of actin (light)
--> myosin end to myosin end
, What is the H zone composed of? Ans✓✓ -only myosin section
--> goes away during maximal contraction
What is the A band composed of? Ans✓✓ -actin and myosin
What is Myosin-ATPase? Ans✓✓ -an enzyme located in the myosin head that
hydrolyzes ATP
What is the importance of ATP in muscular contraction? Ans✓✓ -important for
bringing Ca+ back to SR
T or F: Muscular relaxation requires ATP. Ans✓✓ -True
What size neuron do type I fibers have? Ans✓✓ -small sized
--> <300 fibers
What size neuron do type II fibers have? Ans✓✓ -large sized
---> >300 fibers
T or F: Type I and II fibers with the same diameter will distribute the same
amounts of force. Ans✓✓ -True
T or F: Fibers w/ same diameter will distribute the same amounts of power
Ans✓✓ -False
--> Type II fibers= more power
Muscle fiber peak power order Ans✓✓ -Type IIx> Type IIa> Type I
