Chapter 9 and 10 Practice Quizzes Flashcards
The fibrous outer covering of a muscle that contains the muscle and allows it to slide over adjacent structures is the _________.
epimysium
What is the region of a sarcomere that contains only thick filaments called?
H band
The two muscle proteins that “slide across” each other as described by the sliding filament model are _____________.
actin and myosin
An action potential sweeps across the sarcolemma, and the sarcoplasmic reticulum releases calcium ions during which of the following?
latent period
The power stroke releases energy from ATP that was stored in the resting state of the __________.
myosin head
The smooth, steady increase in muscular tension produced as a movement continues is the result of _______.
recruitment
Which of the following occurs when a high stimulation frequency completely eliminates the relaxation phase?
complete tetanus
Muscle length increases when the load is greater than the contractile force of the muscle during which type of contraction?
eccentric
Which statement regarding glycolysis is FALSE?
It provides a net gain of two ATP molecules and generates two pyruvate molecules.
It is an aerobic process.
It is not the primary source of energy required by active skeletal muscles.
It occurs in the cytoplasm of a cell.
It provides a net gain of two ATP molecules and generates two pyruvate molecules. TRUE
It is an aerobic process. FALSE. Glycolisis in anaerobic; mitochondrial ATP production (95%) is aerobic.
It is not the primary source of energy required by active skeletal muscles. TRUE - ATP is.
It occurs in the cytoplasm of a cell. TRUE - it is a mitochondrial activity
The metabolic cycling of lactate and glucose between the liver and skeletal muscle is the _____________.
Cori cycle
What changes occur to the structural features of a sarcomere, according to the sliding filament theory of muscle contraction?
it shortens
What happens inside the muscle fiber when nervous stimulation ceases?
sarcomeres return to resting potential (refractory period)
Because the tension a muscle fiber produces is related to sarcomere length, what would occur if the zone of overlap were reduced to nothing?
there would be no tension; no action
Why do sprinters usually experience muscle fatigue?
they rely on fast fibers, which are powerful but fatigue rapidly.
What enables neurons and muscle cells to have electrically excitable plasma membranes, whereas most cells depolarize and repolarize only locally?
electrical impulse (action potential) is propogated across the membranes by opening and closing of Na+ and K+ voltage-gated channels.
