ECPI BIO 111 Ch:9 Exam Questions
With 100% Verified Correct Answers.
A Sarcomere consists of the following:
I Band, A Band, H Zone , Z Line (Z Disc), M Line
I Band
Light band composed of thin actin filaments
A Band
Dark band composed of thick myosin filaments with portions overlapped with thin
actin filaments
H Zone
Center of A band; composed of thick myosin filaments
Z Line (Z Disc)
Sarcomere boundary in center of I band; anchors filaments in place
M Line
Center of sarcomere and A band; anchors thick filaments
Thick Filaments in Muscle Fibers
Composed of myosin protein; heads form a cross-bridge with thin filaments
Thin Filaments in Muscle Fibers
Composed of actin protein; associatd with troponin (calcium sensor) and tropomyosin (blocks
myosin from binding to actin), which prevent cross-bridge formation when muscle is not
contracting
Contraction of a Skeletal Muscle Fiber:
, Requires interaction from several chemical and cellular components; results from a movement
within the myofibrils, in which the actin and myosin filaments slide past each other,
shortening the sarcomeres; muscle fibers shortens and pulls on attachment points
Neuromuscular Junction
A type of synapse; site where an axon of motor neuron and skeletal muscle fiber interact;
skeletal muscle fibers contract only when stimulated by a motor neuron
Parts of a Neuromuscular Junction:
Motor neuron; Motor end plate; Synaptic cleft; Synaptic vesicles; Neurotransmitters
Motor Neuron
Neuron that controls skeletal muscle fiber
Motor end plate
Specialized folded portion of skeletal muscle fiber, where fiber binds to neurotransmitter
the only part of the sarcolemma that has receptors for acetylcholine (ACh)
Synaptic Cleft
Space between neuron and muscle fiber, across which neurotransmitter travels
Synaptic Vesicles
Membrane-bound sacs containing neurotransmitters
Neurotransmitters
Chemicals released by motor neuron to deliver message to muscle fiber
Acetylcholine (ACh)
A neurotransmitter that generates muscle impulse that causes release of calcium ions from
SR, which leads to muscle contraction
Acetylcholinesterase
With 100% Verified Correct Answers.
A Sarcomere consists of the following:
I Band, A Band, H Zone , Z Line (Z Disc), M Line
I Band
Light band composed of thin actin filaments
A Band
Dark band composed of thick myosin filaments with portions overlapped with thin
actin filaments
H Zone
Center of A band; composed of thick myosin filaments
Z Line (Z Disc)
Sarcomere boundary in center of I band; anchors filaments in place
M Line
Center of sarcomere and A band; anchors thick filaments
Thick Filaments in Muscle Fibers
Composed of myosin protein; heads form a cross-bridge with thin filaments
Thin Filaments in Muscle Fibers
Composed of actin protein; associatd with troponin (calcium sensor) and tropomyosin (blocks
myosin from binding to actin), which prevent cross-bridge formation when muscle is not
contracting
Contraction of a Skeletal Muscle Fiber:
, Requires interaction from several chemical and cellular components; results from a movement
within the myofibrils, in which the actin and myosin filaments slide past each other,
shortening the sarcomeres; muscle fibers shortens and pulls on attachment points
Neuromuscular Junction
A type of synapse; site where an axon of motor neuron and skeletal muscle fiber interact;
skeletal muscle fibers contract only when stimulated by a motor neuron
Parts of a Neuromuscular Junction:
Motor neuron; Motor end plate; Synaptic cleft; Synaptic vesicles; Neurotransmitters
Motor Neuron
Neuron that controls skeletal muscle fiber
Motor end plate
Specialized folded portion of skeletal muscle fiber, where fiber binds to neurotransmitter
the only part of the sarcolemma that has receptors for acetylcholine (ACh)
Synaptic Cleft
Space between neuron and muscle fiber, across which neurotransmitter travels
Synaptic Vesicles
Membrane-bound sacs containing neurotransmitters
Neurotransmitters
Chemicals released by motor neuron to deliver message to muscle fiber
Acetylcholine (ACh)
A neurotransmitter that generates muscle impulse that causes release of calcium ions from
SR, which leads to muscle contraction
Acetylcholinesterase
