A & P - Chapter 10 Practice Test

An example of an activity that requires anaerobic endurance is: running a marathon a 10-mile bicycle ride a 50-yard dash a 3-mile run

a 50-yard dash

Which of the following has been correlated with muscle fatigue? increased muscle performance resulting from an increased pain threshold an increase in metabolic reserves within the muscle fibers a decline in pH within the muscle altering enzyme activities an increase in pH within the muscle fibers affecting storage of glycogen

a decline in pH within the muscle altering enzyme activities

The thick filaments consist of: a helical array of actin molecules a pair of protein strands wound together to form chains of myosin molecules a helical array of myosin molecules a pair of protein strands wound together to form chains of actin molecules

a helical array of myosin molecules

The thin filaments consist of: a helical array of myosin molecules a pair of protein strands wound together to form chains of myosin molecules a pair of protein strands together to form chains of actin molecules a helical array of actin molecules

a pair of protein strands together to form chains of actin molecules

The length of time a muscle can continue to contract while supported by mitochondrial activities is referred to as: recruitment hypertrophy aerobic endurance anaerobic endurance

aerobic endurance

The two mechanisms used to generate ATP from glucose are: aerobic respiration and anaerobic glycolysis ADP and creatine phosphate cytoplasm and mitochondria none of the above

aerobic respiration and anaerobic glycolysis

Layers of smooth muscle in the reproductive tract of the female are important in: movement of oocytes movement of sperm if present expelling of the fetus at delivery all of the above

all of the above

The amount of tension produced in the skeletal muscle as a whole is determined by the: internal tension produced by the stimulated muscle fibers external tension produced by the stimulated muscle fibers total number of muscle fibers stimulated all of the above

all of the above

Which of the following could cause muscle atrophy? paralysis a lack of regular stimulation of muscle fibers wearing a cast on a broken limb all of the above

all of the above

Which of the following is necessary for smooth muscle contraction? Sarcomeres must contract as a result of crossbridges forming between actin and myosin. Calcium ions must interact with calmodulin to trigger muscle contraction. The zone of overlap must increase, but the length of the M line remains constant. T tubules must transmit the action potential to the sarcoplasmic reticulum.

Calcium ions must interact with calmodulin to trigger muscle contraction.

Which of the following would not be an effective source of energy for muscle contraction? DNA glycogen ATP creatine

DNA

The area of the A band in the sarcomere consists of: Z line, H band, M line thin filaments only M line, H band, zone of overlap overlapping thick and thin filaments

M line, H band, zone of overlap

A blending of epimysium, perimysium, and endomysium that forms a broad sheet at the end of a muscle is known as a(n): ligament myofibril sarcomere aponeurosis

aponeurosis

The order of the sequential-cyclic reactions that occur at an active site during cross-bridging is: attach, return, pivot, detach attach, detach, pivot, return attach, return, detach, pivot attach, pivot, detach, return

attach, pivot, detach, return

Mitochondrial activities are relatively efficient, but their rate of ATP generation is limited by the: availability of oxygen presence of enzymes energy demands of other organelles availability of carbon dioxide and water

availability of oxygen

The cardiovascular system uses which types of muscle? cardiac, smooth, and skeletal cardiac and smooth skeletal and cardiac smooth and skeletal

cardiac and smooth

Peak tension production occurs when all motor units in the muscle contract in a state of: wave summation twitch treppe complete tetanus

complete tetanus

Troponin and tropomyosin are two proteins that can prevent the contractile process by: covering the active site and blocking the actin-myosin interaction inactivating the myosin to prevent cross-bridging combining with calcium to prevent active site binding causing the release of calcium from the sacs of the sarcoplasmic reticulum

covering the active site and blocking the actin-myosin interaction

In an isotonic contraction, the: muscle length does not change as a result of the resistance crossbridges must produce enough tension to overcome the resistance tension in the muscle decreases as the resistance increases tension in the muscle varies as it shortens

crossbridges must produce enough tension to overcome the resistance

After contraction, a muscle fiber returns to its original length through: elastic forces and the movement of opposing muscles the tension produced by the initial length of the muscle fiber the active mechanism for fiber elongation involvement of all the sarcomeres along the myofibrils

elastic forces and the movement of opposing muscles

Excitation-contraction coupling forms the link between: the release of Ca++ to bind with the troponin molecule electrical activity in the sarcolemma and the initiation of a contraction depolarization and repolarization the neuromuscular junction and the sarcoplasmic reticulum

electrical activity in the sarcolemma and the initiation of a contraction

During the recovery period, the body's oxygen demand is: elevated above normal resting levels an irrelevant factor during recovery decreased below normal resting levels unchanged

elevated above normal resting levels

Nerves and blood vessels are contained within the connective tissues of the: epimysium and perimysium epimysium and endomysium endomysium only perimysium only

epimysium and perimysium

The hormone responsible for stimulating muscle metabolism and increasing the force of contraction during a sudden crisis is: thyroid hormone epinephrine testosterone growth hormone

epinephrine

The type of skeletal muscle fibers that have low fatigue resistance are: intermediate fibers fast fibers type I fibers slow fibers

fast fibers

Athletes training to develop anaerobic endurance perform: stretching, flexibility, and relaxation exercises frequent, brief, intensive workouts a combination of weight training and marathon running infrequent, long, relaxing workouts

frequent, brief, intensive workouts

The phases of a single twitch, in sequential order, are: latent period, relaxation phase, contraction phase latent period, contraction phase, relaxation phase contraction phase, latent phase, relaxation phase relaxation phase, latent phase, contraction phase

latent period, contraction phase, relaxation phase

The reason that control over leg muscles is less precise than control over the muscles of the eye is: many muscle fibers are controlled by many motor neurons a single muscle fiber is controlled by a single motor neuron single muscle fibers are controlled by many motor neurons many muscle fibers are controlled by a single motor neuron

many muscle fibers are controlled by a single motor neuron

All of the muscle fibers controlled by a single motor neuron constitute a: crossbridge myoneural junction motor unit sarcomere

motor unit

The amount of tension produced by an individual muscle fiber ultimately depends on the: number of pivoting crossbridges all-or-none principle number of calcium ions released number of contracting sarcomeres

number of pivoting crossbridges

The major support that the muscular system gets from the cardiovascular system is: nutrient and oxygen delivery and carbon dioxide removal decreased volume of blood and rate of flow for maximal muscles contraction a direct response by controlling the heart rate and the respiratory rate constriction of blood vessels and decrease in heart rate for thermoregulatory control

nutrient and oxygen delivery and carbon dioxide removal

Repeating contractile units that make up a myofibril are called: sarcomeres thick filaments thin filaments A bands

sarcomeres

A high blood concentration of the enzyme creatine phosphokinase (CPK) usually indicates: the mitochondria are malfunctioning serious muscle damage the release of stored energy an excess of energy is being produced

serious muscle damage

The three types of muscle tissue are: elastic, collagen, fibrous skeletal, cardiac, smooth voluntary, involuntary, resting epimysium, perimysium, endomysium

skeletal, cardiac, smooth

Extensive blood vessels, mitochondria, and myoglobin are found in the greatest concentration in: type II fibers intermediate fibers fast fibers slow fibers

slow fibers

Which type of muscle fiber would be dominant in a muscle like the gastrocnemius, a calf muscle that contracts during standing and walking? intermediate fibers slow fibers fast fibers white fibers

slow fibers

What type(s) of muscle tissue do(es) not contain sarcomeres? cardiac skeletal smooth all of the above

smooth

The transmission of an action potential along the T tubules stimulates the release of calcium from which structure in the sarcomere? troponin terminal cisternae tropomyosin myofibril sarcolemma

terminal cisternae

Cardiac muscle has the feature of automaticity, which is the ability to contract without neural stimulation. Which of the following statements accurately explains this unique feature? The heart is full of fast muscle fibers and can contract quickly enough not to require neural stimulation. Calmodulin interacting with calcium and myosin light chain kinase triggers interactions between actin and myosin. Because cardiac muscle is not under voluntary control, it does not respond to neural stimulation. Specialized pacemaker cells within the heart determine the rate of contraction of heart muscle. None of the above.

Specialized pacemaker cells within the heart determine the rate of contraction of heart muscle.

On average, girls have smaller muscles and therefore less muscle mass than boys. Which hormones cause this difference between girls and boys? growth hormone and testosterone epinephrine and thyroid hormone thyroid hormone and growth hormone epinephrine and testosterone

growth hormone and testosterone

Which of the following is an example of an isometric contraction? walking picking up a toddler who is sitting on the floor flexing the biceps muscle while holding a 10-pound weight holding a heavy stack of books above the ground

holding a heavy stack of books above the ground

A muscle producing peak tension during rapid cycles of contraction and relaxation is said to be in: recruitment incomplete tetanus treppe complete tetanus

incomplete tetanus

Smooth muscle contractions in the respiratory passageways cause: decreased resistance to air flow no change in resistance to air flow immediate death increased resistance to air flow

increased resistance to air flow

The process of reaching complete tetanus is obtained by: activation of additional motor units applying a second stimulus before the relaxation phase has ended decreasing the concentration of calcium ions in the cytoplasm increasing the rate of stimulation until the relaxation phase is completely eliminated

increasing the rate of stimulation until the relaxation phase is completely eliminated

The bacterium Clostridium tetani causes prolonged muscle contractions by doing which of the following? competing for the ACh receptor sites on the motor end plate inhibiting the mechanism that suppresses motor neuron activity causing a decrease in the amount of available ACh releasing a toxin that causes flaccid paralysis

inhibiting the mechanism that suppresses motor neuron activity

Johnny, a 55-pound 6-year-old boy, wants to be as strong as some of the professional weight lifters he sees on television. He goes outside, grabs the front bumper of his mother's SUV, and attempts to raise it off the ground. The SUV does not move, but Johnny has succeeded in demonstrating which kind of muscle contraction? eccentric isotonic isometric concentric

isometric

Structurally, smooth muscle cells differ from skeletal muscle cells because smooth muscle cells: contain a network of T tubules lack myofibrils and sarcomeres possess striations contain many nuclei

lack myofibrils and sarcomeres

In anaerobic glycolysis, glucose is broken down to pyruvic acid, which is converted to: glycogen acetyl-CoA citric acid lactic acid

lactic acid

The sliding filament theory explains that the physical change that takes place during contraction is that: the thin filaments are sliding toward the center of the sarcomere alongside the thick filaments the thick and thin filaments are sliding toward the center of the sarcomere together the thick filaments are sliding toward the center of the sarcomere alongside the thin filaments the Z lines are sliding toward the H zone

the thin filaments are sliding toward the center of the sarcomere alongside the thick filaments

Skeletal muscles are often called voluntary muscles because: connective tissue harnesses generated forces voluntarily the skeletal muscles contain myoneural junctions they contract when stimulated by motor neurons of the central nervous system ATP activates skeletal muscles for contraction

they contract when stimulated by motor neurons of the central nervous system