muscular system old exam questions Flashcards
which muscle protein given muscle elasticity and returns the sarcomere to resting length after relaxation
- titin
- myomesin
- dystrophin
- troponin
titin
skeletal muscle fibers are formed during development through the fusion of embryonic cells called
- sarcomeres
- myofibrils
- myoblasts
- fascicles
myoblasts
according to the sliding filament mechanism
- the A band does not change in length during concentric muscle contraction
- the I band increases in length during concentric muscle contraction
- the zone of overlap decreases during concentric muscle contraction
- the H zone increases during concentric muscle contraction
the A band does not change in length during concentric muscle contraction
electrical signals in the t-tubule membrane cause the sarcoplasmic reticulum to release ___ in the ___ fluid
- acetylcholine; extracellular
- Na+; extracellular
- Ca2+; intracullular
- K+; intracellular
Ca2+, intracellular
place in order the following list of events associated with neuromuscular transmission
- acetylcholine diffuses across the synaptic cleft
- electrical signal is generated in the muscle cell membrane
- synaptic vesicles fuse with the cell membrane and release their contents
- acetylcholine binds to the acetylcholine receptor on the motor end plate
- electrical signal reaches the synaptic terminal of a motor neuron
5,3,1,4,2
motor units..
- are recruited on the basis of size (smallest motor units are recruited first) during voluntary contraction
- consists of all motor neurons that innervate a particular muscle
- can include multiple muscle fiber types in a simple motor unit
- can include multiple muscle fiber types in a single motor unit
are recruited on the basis of size (smallest motor units are recruited first) during voluntary contraction
the type of contraction in which the muscle fibers generate tension while they lengthen is called
- isokinetic
- concentric
- eccentric
- isometric
eccentric
temporal summation in a skeletal muscle fiber occurs when
- there is an increase in the frequency of action potentials sent to the muscle fiber
- aadditional motor units are recruited to increase tension
- one action potential cause increased tension in a muscle fiber
- the thick and thin filaments are maximally overlapped
there is an increase in the frequency of action potentials sent to the muscle fiber
which of the following could contribute to fatigue
- high levels of free phosphate in the sarcoplasm
- depletion of glycogen from the sarcoplasm
- high levels of lactic acid in the sarcoplasm
- all of the above
- all of the above
place in order the following list of the events that occur during skeletal muscle contraction, beginning with the arrival of an electrical signal at the t-tubule membrane
- myosin heads bind to actin forming cross bridges
- calcium ions is released from the SR
- the myosin head pivots toward the center of the sarcomere
- calcium ions binds to troponin
- the myosin head binds an ATP molecule and detaches from actin
2,4,1,3,5
anaerobic glycolysis..
- occurs in the cytoplasm and is very fast
- is the most efficient method to produce ATP
- can support from 40 minutes to several hours of skeletal muscle contraction
- requires oxygen to run for any length of time
occurs in the cytoplasm and is very fast
in skeletal muscle the myosin binding sites on actin become exposed and available for cross bridging formation immediately after
- actin binds to ATP
- calcium binds to tropomyosin on the thick filament
- troponin on the thin filament binds to myosin
- calcium binds to troponin on the thin filament
calcium binds to troponin on the thin filament
the muscle twitch
- is the result of a series of action potentials that quickly stimulate the muscle fiber
- duration is longer in slow oxidative fibers compared to fast glycolytic fibers
- includes the latent period which tension is increasing
- is the primary mechanism of muscle contraction in skeletal muscle contraction while performing daily activities like walking
duration is longer in slow oxidative fibers compared to fast glycolytic fibers
which of the following statements about skeletal muscle fiber types is true
- FG fibers have low levels of creatine phosphokinase
- SO fibers have a lot of mitochondria
- FG fibers have a lot of myoglobin
- SO fibers produce a lot of force
SO fibers have a lot of mitochondria
choose the answer that best completes the following statement. in skeletal muscle cross bridges form between
- actin and tropomyosin
- troponin and tropomyosin
- actin and troponin
- actin and myosin
actin and myosin
in the cori cycle lactic acid
- is converted to creatine after strenuous exercise
- is converted to glucose in liver cells
- is used directly by mitochondria to produce ATP
- is converted by glycolysis in muscle cells
is converted to glucose in liver cells