Exercise Physiology Exam #2
Four-to-ten weeks of anaerobic training (high intensity exercise lasting 10-30 seconds) can increase the peak anaerobic capacity by ______ across individuals
3-25%
Following a single bout of resistance exercise training, muscle proteins synthesis can remains elevated about sedentary levels for as much as ______ in both trained and untrained individuals.
35-50 hours
Which of the following factors DO NOT contribute to a decline in VO2 observed during 84 days of detraining?
A decrease in maximal heart rate
The specific tension (i.e force production per cross sectional area of fiber) differs between fiber types. Which of the following answers is correct relative to specific force production?
both Type IIx is greater than type I and IIa and Type IIx is slightly greater than type IIa are correct
The increase in VO2 max that occurs following 16 months of endurance exercise training results from
both an increase in the maximal a-VO2 difference and an increase in maximal cardiac output are correct
The excitatory neurotransmitter
both result in graded depolarization of the dendrites and cell body and promotes excitatory postsynaptic potentials are correct
Which of the following has been shown to cause muscle fatigue?
both the accumulation H+ and the accumulation of inorganic phosphate are correct
The motor cortex is concerned with voluntary movement and is located within the
cerebrum
The term kinesthesia refers to
conscious recognition of the position of body parts with respect to each other
Which of the following factors DO NOT contribute to the endurance exercise training-induced increases in fat metabolism during exercise?
increased fat storage in the liver
Which of the following factors does NOT contribute to the endurance exercise training-induced improvement in stroke volume during exercise?
increased peripheral resistance
One of the proposed mechanisms to explain the positive impact of postactivation potential on muscle performace is that low intensity muscle contractions result in phosphorylation
increasing the muscles sensitivity to calcium
Which of the following statements about multiple sclerosis (MS) are NOT true
MS results in damage to neurons with the basal ganglia
Which of the following statements are true about muscle chemoreceptors
Muscle chemoreceptors respond to changes in the concentration of hydrogen ions
A highly successful endurance athlete would likely have _____ compared a sedentary person
a higher percentage of type I fibers
Several factors contribute to neural drive. Which one of the following factors is NOT a contributor to neural drive?
activation of the Golgi tendon organ
A muscle (i.e. prime mover) that results in movement of a limb in the desired direction is labeled as
an agonist
The thin muscle cells located within the muscle spindle are called
intrafusal fibers
Their removal of damaged mitochondria in skeletal muscle and other cells is called
mitochondria endocytosis
Endurance exercise training results in an increase in mitochondria volume within skeletal muscle fibers. The process of synthesizing mitochondria in cells is called
mitochondrial biogenesis
A "movement plan" is first developed by the ______ before being sent to spinal centers for modification
motor cortex
The motor neuron and all the muscle fibers it innervates is called a
motor unit
The phenomenon that previous strength training accelerates the re-acquisition of both muscular strength and hypertrophy is commonly referred to as
muscle memory
Action potential is generated when an excitatory stimulus
opens sodium channels
Neurons are negatively charged on the inside of the cell with respect to the charge on the exterior of the cell. The electrical charge difference is called
resting membrane potential
The cell membrane around a muscle fiber is called
sarcolemma
Cross-sectional studies demonstrate that the physiological variable responsible for the large variation in VO2 max across the normal (untrained) population is maximal
stroke volume
Postactivation potentiation is defined as
the increase in muscle force production that occurs following a bout of non-fatiguing, submaximal contractions
The ________ is the organ located in the inner ear and is responsible for maintaining the general equilibrium
vestibular apparatus
Research reveals that resistance training included muscle hypertrophy is associated with an increase in myonuclei. The source of these additional myonuclei is
via satellite cell activation
Endurance exercise training programs (e.g. 3 days/week @ 60% VO2 max for 12 weeks) typically results in a
15-25% improvement in VO2 max
The average VO2 max value for the young (e.g. 21 yrs old) male sedentary population is approximately
45 ml*kg^-1 * min^-1
Heritability (i.e. genetics) determines approximately _____% of VO2 max variability in sedentary adults
50
High responders to endurance exercise training (i.e. individuals that achieve large increases in VO2 max) can achieve up tp _____% improvement in VO2 max following a prolonged and intense training program.
50
In theory, concurrent resistance and endurance exercise training can impair muscle protein synthesis following a bout of resistance exercise. The proposed mechanisms to explain this inhibition is
AMP kinase activation of TSC2
The principle of specificity of training refers to the fact that exercise training is specific to
- the muscles involved in the activity - the fiber types recruited - the principle energy system (i.e. aerobic vs anaerobic) involved in the activity
A single bout of resistance exercise training increases muscle protein synthesis by as much as _____% above resting levels?
50-150
It is estimated that ____% of differences in muscle mass between individuals can be explained by genetic variation
80
It is estimated that ____% of the differences in muscle mass between individuals can be explained by genetic variation
80
The breakdown of ATP in muscle is accomplished via the enzyme
ATPase
The two major contractile proteins found in skeletal muscle are
actin and myosin
Disease-related muscle wasting is termed
cachexia
Anatomically, the nervous system can be divided into two main parts:
central and peripheral
The area of the brain that aids in control of movement and may initiate fast ballistic movements is the
cerebellum
resistance training results in a
fast-to-slow shift muscle fiber types
Which of the following physiological factors does NOT contribute to the endurance exercise training-induced increase in the maximal a-VO2 difference?
increased hemoglobin in the blood
Endurance training has been shown to reduce the oxygen deficit in subjects performing a bout of submaximal exercise. This is likely due to
increases in the number of mitochondria and capillaries
The sodium-potassium pump neurons is an active transport pump that
moves 3 molecules of sodium out of the cell and returns 2 molecules of potassium into the cell
The peak power generated by any skeletal muscle increases with velocities of movement up to movement speed of 200-300 degrees per second; at higher shortening velocities, the peak power output declines. Which of the following factors can explain this oberservation?
muscle force production decreases with high shortening velocities because fewer cross-bridges are connected and therefore, les force is produced.
During the first four months of an endurance exercise training program, the initial increase in VO2 max is primarily due to
neural adaptations
Endurance training results in increased mitochondrial and capillary density in muscle but has no effect on muscle glycolytic capacity. This is an example of what training principle?
specificity
The summing of many excitatory post-synaptic potentials (EPSPs) from a single pre-synaptic neuron over a short time period is called
temporal summation
The term cross-education refers to
the observation that if one limb engages in resistance training, muscular strength increases in the untrained (contralateral) limb
Which type of muscles fiber has been shown to be the most efficient
type I
The amount of force exerted during muscular contraction is dependent on the
type of motor units recruited, the initial length of the muscle, and the nature of the neural simulation
Aging is associated with the loss of muscle mass; this is called sarcopenia. Which of the following statements about sarcopenia are correct?
- muscle mass begins to decline around age 25 - the slow phase of age-related muscle decline ranges from age 25 to 50 years - by age 80, 50% of the total muscle mass can be lost
increased production of radicals in skeletal muscles during periods of prolonged inactivity (prolonged bedrest) and promotes muscle atrophy because:
- oxidative stress activates in muscle fibers - oxidative stress decreases protein synthesis in muscle fibers -oxidative stress prevents mTOR activation
Which of the following statements are true about the effect of endurance training or detraining on mitochondria volume in human skeletal muscle?
-Five weeks of endurance training can increase skeletal muscle mitochondrial volume by two times about normal -seven days of detraining can reduce mitochondrial volume by 50 % below trained level -After a period of detraining, approx. 4 weeks of retraining is required to regain the lost mitochondrial volume
A popular belief among some athletes is that exercise-induced muscle cramps in a single muscle (e.g. gastrocnemius) results from dehydration and blood electrolyte imbalance. Which of the following observations DO NOT support this position?
-dehydration and electrolyte imbalance would likely impact all skeletal muscles -exercise-induced muscle cramps can occur without any change in blood electrolyte concentrations -static stretching of the cramping muscle often relieves the cramp
A single bout of resistance exercise training results in an increase in skeletal muscle protein synthesis. This exercise-induced increase in muscle protein synthesis can occur within _____ following the exercise session.
hours
Following an acute bout of endurance exercise training, the increase in mitochondria biogenesis occurs within _____ following the completion of the exercise session.
hours
Which of the following factors do not contribute to the endurance exercise training-induced improvement in VO2 max?
increase maximal heart rate
Which of the following endurance training adaptations does NOT results in lower lactate production in the contracting muscles?
increased glycogen utilization
Which of the following endurance training adaptations assist in maintain acid-base balance during exercise?
increased mitochondria volume in skeletal muscle
Following an acute bout of endurance exercise training, the rise in the activity of calcinuneurin, calmodulin kinase, and AMP kinases occurs within ___ following the exercise session.
minutes
During the first 8 weeks of resistance training program, the initial increase in muscular strength is primarily due to
neural adaptations
Muscles receive a neural activation signal from motor neurons located in the spinal cord. This is neural signal is referred to as
neural drive
Chronic traumatic encephalopathy is associated with
neuronal death, loss of axons, chronic inflammation
Which of the following training adaptations does NOT occur in skeletal muscles following 4-10 weeks of anaerobic exercise training?
none of these answers are correct -increased muscle buffer capacity -increased activities of myokinase and creatine phosphokinase
Several mechanisms have been proposed to explain why concurrent endurance resistance (strength) training alone. Which of the following mechanisms have NOT been proposed to explain why concurrent training impedes strength development?
none of these are correct neural factors, overtraining, depressed muscle protein synthesis
It is established that resistance exercise training promotes an increase in muscle protein synthesis by activating the mechanistic target of rapamycin (mTOR) which results in increased protein synthesis. Recent evidence suggests that two signaling molecules interact to directly activate mTOR. These molecules are
phosphatidic acid and Ras homologue enriched brain (Rheb)
The connecting point between a motor neuron and muscle fiber is called the
Neuromuscular junction
Which of the following statements about neurons are NOT true
Neurons repolarize by opening chloride channels on the membrane
The neurotransmitter used in the parasympathetic nervous system is
acetylcholine
Nerve fibers that carry impulses toward the central nervous system are called
afferent
resistance training results in an increase of the rate of contractile protein synthesis which is matched by
an increase in the synthesis of collagen in tendons and ligaments
The term hyperplasia refers to
an increase in the total number of muscle fibers
Endurance exercise training has been shown to improve brain function in numerous ways. Which of the following exercise-induced changes in the brain are NOT linked to exercise-induced improvement in cognition
angiogenesis in the cerebellum
Prolonged inactivity of skeletal muscle leads to rapid muscle atrophy, this occurs due to:
both a decrease in muscle protein synthesis and increased protein breakdown in muscle fibers are correct
A potential mechanism that could contribute to central fatigue includes
both depletion of excitatory neurotransmitters in the brain and a decrease in the excitability of the motor cortex are correct
The negative membrane potential in a resting neuron is primarily due to
both diffusion of potassium out of the cell and a higher permeability of the membrane for potassium compared to sodium are correct
The resting membrane potential of neurons is determined by
both the permeability of the cell membrane to various ions and the difference in ion concentration between the intercellular and extracellular fluids are correct
The joint receptors that provide the central nervous system with information about the body position are called
proprioceptors
Which of the following statements about resistance training is NOT true?
resistance training DOES NOT promote hypertrophy and strength gains in people greater than 65 yrs old
Aging is associated with a decline in strength, with most of the decline occurring after the age of 50. The loss of strength is due, in part, to a loss of muscle mass; this age-related loss of muscle mass is termed
sarcopenia
Calcium is stored in muscle within the
sarcoplasmic reticulum
By comparison to the rate of detraining following endurance training, the rate of detraining (i.e. loss of muscular strength) following resistance training program is
slower
The mechanism responsible for the size principle is that compared to large motor neurons
small motor neurons have a small surface area and are easier to depolarize
Fast-twitch fibers (i.e., IIx) contain a relatively
small number if mitochondria and high ATPase activity
Higher brain centers are responsible for developing a general pattern of movement; the specific details of this movement are redefined via a process known as
spinal tuning
Relative to brain health, regular aerobic exercise has been shown to
stimulate neuron info, improve blood flow, enhance learning and memory
The autonomic nervous system can be divided into two functional and anatomical divisions called
sympathetic and parasympathetic
The Golgi tendon organs monitor
tension produced by muscular contraction
several hormones have the potential to increase muscle protein synthesis. These include:
testosterone, insulin-like growth factor-1 (IGF-1), and growth hormone
An important physiological factor that may contribute to the inhibition of motor unit activation during resistance training is
the Golgi tendon organ
Growing evidence reveals that, independent of resistance exercise, _________ can activate mTOR and promote small increase in muscle protein synthesis
the amino acid leucine
Following several weeks of endurance exercise training, the capacity to transport glucose into skeletal muscle fibers is increased. which of the following training-induced changes contribute to this training effect?
the increase in the number of GLUT4 glucose transporters
The formation of cross-bridges that initiates the contractile process in skeletal muscle is triggered by
calcium binding troponin
Neurons can be divided into three basic parts:
cell body, dendrites, axon
Satellite Cells
contribute to muscle growth by dividing and contributing nuclei to existing muscle fibers, reside above the sarcolemma, are undifferentiated cells that play a key role in muscle growth and repair
resistance training increases the specific force production of
type 1 muscle fibers
Skeletal muscle fibers that contain high numbers of mitochondria could be classified as
type I fibers
Equilibrium and balance require input from the
Vestibular apparatus, eyes; joint, tendon, and muscle receptors
Which of the following statements about the myonuclear domain are correct?
- The myonuclear domain is the region of cytoplasm surrounding an individual nucleus - The is importance of the myonuclear domain is that a single nucleus is a responsible for the gen expression for its surrounding cytoplasm - In response to resistance exercise, satellite cells become activated and divide to add additional nuclei to a muscle fiber
The enhanced capacity of the trained muscle to use fatty acids as a fuel results in
- increased uptake of fatty acids - decreased utilization of muscle glycogen - sparing of blood glucose
The heart rate and ventilatory responses to constant load submaximal exercise are lower (i.e. lower heart rate and lower minute ventilation) following an endurance training program. This training-induced adaptation is primarily due to changes in the
trained skeletal muscles
The force velocity curve describes the relationship between speed of muscle shortening (i.e. velocity of movement) and muscle force production. Which of the following statements are true about the influence of muscle fiber type on the force velocity curve?
At any given velocity of movement the peak power generated is greater in a muscle that contains a high percentage of fast fibers (i.e. type IIx) compared with a muscle that contains a high percentage of slow fibers. (i.e. type I)
The addition of myonuclei to growing muscle fibers
Both appears to be essential for optimal muscle hypertrophy in response to resistance training and is likely required training and is likely required to maintain the high level of transcriptional capacity needed to synthesize muscle proteins and allow muscle fibers to grow during resistance training are correct
Which of the following statements about muscle fatigue are true?
Both cause of muscle fatigue during severe exercise is multifactorial and includes increases in phosphate ions and hydrogen ions within the active muscle fibers and increases in hydrogen ions in skeletal muscle contribute to fatigue because hydrogen ions bind to the calcium binding site on troponin are true
Four categories (domains) of exercise intensity exist. Which of the following statements about exercise intensity domains are true?
Both moderate intensity is below the lactate threshold and typically below 60% VO2 max in untrained subjects and Heavy exercise is exercise above the lactate threshold and typically ranges between 60-70% VO2 max are correct
which of the following events occurs first during a voluntary muscle contraction
The innervating alpha-motor neuron reaches an action potential
Neural drive is defined as
The magnitude of the efferent neural output from the central nervous system to the motor units and the muscle fibers that they activate
Repeated sport-related traumatic brain injuries (i.e., concussions) are associated with a higher risk of developing _________.
dementia, Alzheimer's disease, impaired mental function
A muscular contraction that results in a movement of body parts is called a
dynamic contraction
Nerve Fibers that conduct impulses away from the central nervous system are called:
efferent
The layer of connective tissue that surrounds the outside of skeletal muscle (i.e just below the fascia) is called the
epimysium
Neurotransmitter that cause depolarization of membranes are called
excitatory transmitters
The ability of a neuron to respond to a stimulus is termed
irritability
Muscle spindles provide sensory information relative to the
length of muscle
A major regulator of protein synthesis and muscle size is
mTOR