BIOL 2213 EXAM 3 WITH ACCURATE ANSWERS
muscle fiber - ANSWER single muscle cell
Z lines - ANSWER thin dark lines in the middle of the I bands
myofibril - ANSWER subunit of muscle fiber
myofilaments - ANSWER each myofibril is a bundle of parallel protein microfilaments
called
thick - ANSWER A bands contain _____ filaments
myosin - ANSWER thick filaments are primarily composed of
thin - ANSWER the I bands contain ____ filaments
actin ANSWER thin filaments primarily made of
sarcomere ANSWER basic subunit of striated muscle contraction
motor unit ANSWER a somatic motor neuron plus all the skeletal muscle fibers it
innervates
graded contractions ANSWER contractions of varying strength resulting from the
stimulation of different numbers of motor units
, excitation-contraction coupling ANSWER sequence of events from the action potential
to contraction of the sarcomere
calcium - ANSWER excitation-contraction coupling links the muscular system to the
nervous system using
tropomyosin, low - ANSWER in a relaxed muscle when ______ blocks attachment of cross
bridges to actin, the calcium concentration in the sarcoplasm is very ___
rise - ANSWER when a muscle cell is stimulated to contract, the calcium concentration
in the sarcoplasm is quick to
Ach - ANSWER calcium enables ____ to be released across the space between the axon
terminal and motor end plate
Ach - ANSWER skeletal excitation-contraction coupling step 1: somatic neurons release
____ which binds to nicotinic receptors on postsynaptic cell
voltage-gated calcium channels - ANSWER skeletal excitation-contraction coupling step
2: AP produced in postsynaptic cell and conducted alone sarcolemma to open _________
in T-tubules
opened - ANSWER skeletal excitation-contraction coupling step 3: calcium release
channels in s. reticulum are _____
increases - ANSWER skeletal excitation-contraction coupling step 4: calcium
concentration in s. reticulum ____
troponin, tropomyosin - ANSWER skeletal excitation-contraction coupling step 5:
calcium binds to ____ and _______ is removed from the binding site on actin
muscle fiber - ANSWER single muscle cell
Z lines - ANSWER thin dark lines in the middle of the I bands
myofibril - ANSWER subunit of muscle fiber
myofilaments - ANSWER each myofibril is a bundle of parallel protein microfilaments
called
thick - ANSWER A bands contain _____ filaments
myosin - ANSWER thick filaments are primarily composed of
thin - ANSWER the I bands contain ____ filaments
actin ANSWER thin filaments primarily made of
sarcomere ANSWER basic subunit of striated muscle contraction
motor unit ANSWER a somatic motor neuron plus all the skeletal muscle fibers it
innervates
graded contractions ANSWER contractions of varying strength resulting from the
stimulation of different numbers of motor units
, excitation-contraction coupling ANSWER sequence of events from the action potential
to contraction of the sarcomere
calcium - ANSWER excitation-contraction coupling links the muscular system to the
nervous system using
tropomyosin, low - ANSWER in a relaxed muscle when ______ blocks attachment of cross
bridges to actin, the calcium concentration in the sarcoplasm is very ___
rise - ANSWER when a muscle cell is stimulated to contract, the calcium concentration
in the sarcoplasm is quick to
Ach - ANSWER calcium enables ____ to be released across the space between the axon
terminal and motor end plate
Ach - ANSWER skeletal excitation-contraction coupling step 1: somatic neurons release
____ which binds to nicotinic receptors on postsynaptic cell
voltage-gated calcium channels - ANSWER skeletal excitation-contraction coupling step
2: AP produced in postsynaptic cell and conducted alone sarcolemma to open _________
in T-tubules
opened - ANSWER skeletal excitation-contraction coupling step 3: calcium release
channels in s. reticulum are _____
increases - ANSWER skeletal excitation-contraction coupling step 4: calcium
concentration in s. reticulum ____
troponin, tropomyosin - ANSWER skeletal excitation-contraction coupling step 5:
calcium binds to ____ and _______ is removed from the binding site on actin
