KIN 492 Final
Select the best answer: The amount of force that can be produced by a skeletal muscle contraction is determined/regulated by the a. Number of motor units b. Muscle length at rest c. Strength of the neural impulse d. Height and weight
a, b and c
Under which exercise condition will physiological variables (e.g., ventilation, heart rate, oxygen consumption) NOT reach steady state?
maximal graded exercise test (i.e., VO2max test)
Short-term endurance training adaptation that is responsible for initial increases in VO2 max
maximal stroke volume
Biochemical adaptation that is responsible for improving performance and maintaining homeostasis
mitochondrial density
What are the major stages/products of aerobic ATP production in order, from start to finish, when 1 molecule of glucose is your starting substrate?
pyruvate, acetyl CoA, Krebs cycle, electron transport chain
Heat is transferred through infrared rays
radiation
Primary mechanism for heat loss at rest
radiation
Which factor is the most influential when discussing resistance to blood flow?
radius of blood vessel
The components of a biological control system in sequential order
receptor, integrating center/control center, effector
When atrial contraction occurs, the ventricles are ______________.
relaxed and filling
Cellular structure that aids in spreading the wave of depolarization throughout the muscle fiber
transverse tubules
One molecule of glycogen yields a net total of ________ ATP from substrate-level phosphorylation.
3
cardiac output increases until maximal effort is reached; heart rate increases linearly in proportion to exercise intensity; stroke volume increases initially before plateauing at 40% of maximal oxygen uptake.
Cardiovascular responses to incremental exercise
True or False: Homeostasis is defined as the maintenance of a relatively constant, unchanging "normal" internal environment during both stressed and unstressed conditions.
False
True or False: Isovolumic contraction occurs at the end of ventricular systole.
False
The net production of ATP via substrate-level phosphorylation in glycolysis is
2 ATP if glucose is the substrate and # ATP if glycogen is the substrate
True or False: (a−v)O2 difference is considered a central component.
False
The heritability of VO2max and change in VO2max in response to endurance exercise training are roughly ____ %. These findings are supported by the _______ study, which was one of the largest exercise training studies conduced to date, investigating the heritability of the exercise training response.
50%; Heritage Family
Which of the following endurance training adaptations assist in maintaining acid-base balance during exercise? A. increased number of mitochondria in skeletal muscle B. increased M4 form of LDH C. increased lactate production D. increased pyruvate formation
A. increased number of mitochondria in skeletal muscle
The enzyme responsible for the synthesis of ATP located at the end of the electron transport chain is
ATP synthase
Energy Systems: Generates ATP using a single enzymatically controlled process.
ATP-PC
Energy Systems: Provides the least amount of ATP
ATP-PC
Energy Systems: This energy system uses phosphocreatine stored within the muscle cell.
ATP-PC
This is the simplest and most rapid method to produce ATP during exercise
ATP-PC System
An increase in left ventricular end-diastolic volume (EDV) would result in which of the following changes (select all that apply): (a) increased stretch of the myocardium (b) increased contractility (c) decreased end-systolic volume (ESV) (d) increased volume of blood being ejected from heart per beat
All
All of the factors listed below contribute to the improvements in VO2 max that occur following endurance training, with the EXCEPTION of (select all that apply) A. genetics B. increased maximal muscle blood flow C.Decreased sympathetic nerve activity D. increased maximal stroke volume E. decreased afterload
All of these factors contribute to training induced improvements in VO2 max
Cardiovascular responses to exercise: What is the physiological rationale to explain why blood pressure and heart rate responses are higher during arm vs. leg exercise performed at a constant work load?
Blood is redistributed to active vs. inactive tissue via vasoconstriction; more blood is being directed to the upper than lower body, resulting in greater resistance to blood flow and hence, MAP & HR.
At an RER of 0.95, which of the following fuel sources are being utilized the most? Carbohydrates 50% Fats / 50% Carbohydrates Protein Fats
Carbohydrates
Muscle fibers can be categorized in terms of maximal force production, contraction velocity, maximal power output, and muscle fiber efficiency, all of which are considered _____ properties.
Contractile
True or False: Cardiovascular drift is observed during prolonged, constant-load exercise and is characterized by a gradual decrease in heart rate and gradual increase in stroke volume, while cardiac output is maintained.
False
True or False: Redistribution of blood flow during exercise is achieved by vasodilation of blood vessels to active tissues and vasoconstricting blood vessels to inactive tissues. These adjustments are mediated by nitric oxide, a potent vasoconstrictor, secreted by the endothelium.
False
True or False: SV, HR and (a−v)O2 difference will increase linearly with exercise intensity until VO2max is reached.
False
True or False: The action potential of a contractile myocyte is distinct because it has a long refractory period (or visible plateau), which is caused by a delayed influx of extracellular potassium into the cell.
False
True or False: The heart is comprised of four chambers, two types of cardiac muscle cells, and although it is considered "one pump", it really encompasses three different pumps to the various circulations, i.e., venous, pulmonary, and systemic circulations.
False
True or False: The right ventricle has the greatest amount of myocardium due to the higher pressure it must overcome to eject blood from the heart into pulmonary circulation.
False
True or False: The use of an electrocardiogram (ECG) to diagnose myocardial ischemia or other electrophysiological abnormalities of the heart is most accurate when it is performed under resting conditions.
False
True/False: Neurotransmitters can only induce excitatory postsynaptic potentials.
False
During incremental exercise, fuel selection switches from ______ as the primary substrate to ______ .
Fats to carbohydrates
Energy Systems: Provides the greatest amount of ATP without using oxygen
Glycolysis
End-diastolic volume (EDV) or preload increases as a result of endurance training. In the SHORT-TERM, increases in EDV are primarily due to ________ while LONGER-TERM adaptations are due to ________, both of which increase the contractility of the heart via the ________.
Increase in plasma volume; increase in left ventricular volume; Frank Starling Mechanism
Energy Systems: This energy system can convert various substrates (e.g., fats and carbohydrates) into ATP.
Oxidative phosphorylation
Energy Systems: This energy system predominates at rest and during activities of daily living (i.e., low metabolic demand).
Oxidative phosphorylation
Energy Systems: This energy system requires oxygen to produce ATP.
Oxidative phosphorylation
Consider an ECG of a normal heart cycle at rest: The ______ represents ventricular depolarization or ventricular ________ , a process that involves the _________ of the myocardium.
QRS complex; systole; contractile myocytes
Of the sites listed below, which is/are responsible for facilitating gas exchange in the lungs? Conducting zone Type II alveolar cells Respiratory zone Diaphragm Bronchioles All the above
Respiratory zone
You are exercising outside on a hot, dry, sunny day (i.e., ambient temperature is high but relative humidity is low). You are unable to exercise very long because you "overheat". Of the statements listed below, which provides the most sound physiologic rationale for your reduced capacity to thermoregulate in this type of environment?
Reversed thermal gradient; air temperature is greater than skin temperature, resulting in heat gain vs heat loss
What is the normal order of the conducting system of the heart?
SA node, AV node, Bundle of His, Purkinje fibers
Heart rate is under the control of the autonomic nervous system. Specifically, which two branches?
Sympathetic and Parasympathetic
Fick's law of diffusion states that the rate of gas transfer is proportional to
The tissue area, the diffusion coefficient of the gas, and the difference in the partial pressure of the gas on the two sides of the tissue
True or False: (a−v)O2 difference describes the amount of O2 that is taken up by the tissues from arterial blood
True
True or False: (a−v)O2 difference will increase during exercise due to the increased metabolic demand and higher oxygen uptake in skeletal muscle.
True
True or False: A classic indication of myocardial ischemia, or lack of blood flow to the heart muscle, is a depression in the S-T segment on an electrocardiogram (ECG).
True
True or False: Different from the action potential of skeletal muscle, the pacemaker-conduction cell has a "wandering baseline" that enables it to be autorhythmic or myogenic in nature.
True
True or False: Pressure (in mmHg) is higher in the atria at the end of diastole compared to the pressure in the ventricles.
True
Arterial Lumen: The ________ of arterioles contains the greatest amount of ________ , which enables these vessels to regulate blood flow via vasoconstriction and vasodilation.
Tunica media; smooth muscle
Which muscle fiber type has the greatest number of capillaries and mitochondria, is the most fatigue resistant, but generates the least amount of force?
Type I
Muscle fiber types from slowest to fastest in humans
Type I, Type IIa, Type IIx
The Fick equation states that __________ , meaning that either an __________ or __________ would result in increased oxygen uptake.
VO2 = Q x (a-v)O2 diff; increase in Q, increase in mixed arteriovenous O2 difference
What is the primary role of NAD+ during aerobic metabolism? a. NAD+ acts as a carrier molecule; accepts hydrogens & their electrons during a series of oxidation reactions and shuttles them to the electron transport chain b. NAD+ accepts hydrogen(s) after glyceraldehyde-3-phosphate is oxidized, which permits substrate-level phosphorylation to produce 1,3-biphosphoglycerate c. NAD+ "primes" blood glucose for glycolysis by catalyzing the phosphorylation of glucose to form glucose 6-phosphate (a "sugar phosphate") d. All of the above are true regarding the role of NAD+ during aerobic metabolism e. a & c
a
Which of the following factors does NOT contribute to the endurance training0induced improvement in stroke volume during exercise? a. increased peripheral resistance b. increased EDV c. increased cardiac contractility d. decrease in total peripheral resistance
a
Which of the following is/are the PRIMARY cooling mechanism(s) in humans? a. increased sweat rate b. increased skin blood flow c. cutaneous vasodilation d. increased catecholamine & thyroxin release e. a & b f. a & c
a
Which of the following statements (in its entirety) is MOST accurate in describing the relationship between ventilation and perfusion in the lungs at rest? A. There is greater ventilation than perfusion at the base of the lung, which is indicated by a V/Q ratio < 1.0 B. There is greater perfusion than ventilation at the apex of the lung, which is indicated by a V/Q ratio > 1.0 C. Ventilation and perfusion are perfectly matched through the lung, which is indicated by a V/Q ratio = 1.0
a
Which of the following is/are considered a central component of VO2? (select all that apply) (a) Cardiac output (b) Stroke volume (c) (a-v) O2 difference (d) Capillary density
a and b
Which of the following is/are true regarding the inspiratory phase of ventilation? (select all that apply) a. intrapulmonary pressure decreases b. intrapulmonary pressure increases c. the diaphragm contracts & moves downward in the thoracic cavity d. it is a passive process e. it can be an active process, but this only helps during exercise
a and c
In general, long-duration low-intensity activities (Select all that apply) a. results in oxidative phosphorylation being the predominant contributor of ATP b. increases the body's reliance on rapid glycolysis c. results in a greater formation of lactic acid d. increases the body's reliance on slow glycolysis
a and d
Skeletal muscle fuel utilization shifts from carbohydrates to primarily fats as a result of endurance training. Why? (Select all that apply) A. increase in the free fatty-acid transportation from the plasma into the mitochondria B. increase the enzymes involved in glycolysis C. increase in the cross-sectional area of type II muscle fibers and reliance on anaerobic energy systems D. shift in muscle fiber type towards fibers with greater oxidative properties
a and d
By definition, an endergonic reaction is
a chemical reaction that requires energy to be added before the reaction will take place
Of the factors listed below, which contribute to the increase in maximal (a-v) O2 difference that occurs with endurance training? (select all that apply) a. increase in muscle blood flow b. increase in capillary density c. mitochondrial biogenesis d. increase in stroke volume
a, b, and c
Select the best answer: Which of the following is/are true regarding skeletal muscle contraction? a. The Z-lines of a sarcomere come closer together b. Myelin filaments slide past actin filaments c. Actin filaments slide past myosin filaments d. The H-zone is at its widest width e. Require a neural impulse to initiate contraction
a, c and e
Pyruvate is converted to acetyl CoA in
aerobic metabolism
Which heart valves separate the atria from the ventricles?
atrioventricular valves
Endurance training results in increased mitochondrial and capillary density in muscle but has no effect on glycolytic capacity. This is an example of what training principle? a. overload b. specificity c. reversibility d. biochemical and contractile properties e. a & d
b
Of the variables listed below, which is/are considered the most important biochemical adaptations for explaining why oxygen deficit during submaximal exercise is lower after becoming aerobically trained? a. increased number of capilaries b. increased number of mitochondria c. less lactate formation d. less glycolysis e. less depletion of phosphocreatine
b
Which of the following endurance training adaptations does NOT result in lower lactate production in the contracting muscles? a. increased H4 form of LDH b. increased glycogen utilization c. increased mitochondrial uptake of pyruvate d. decreased pyruvate formation
b
Which of the following is/are MOST influential in determining resistance to airflow? a. partial pressure of the gases b. diameter of the airway c. pressure difference between the start and the end of the airway d. intrapulmonary pressure
b
Which of the following mechanisms is/are responsible in assisting blood return to the heart? (select all that apply) (a) vasoconstriction (b) skeletal muscle pump (c) respiratory pump (d) one-way valves in the arteries (e) arterial baroreceptors (i.e., baroreflex)
b and c
Which factors cause blood pressure to DECREASE? (select all that apply): (a) Increased blood volume (b) Decreased heart rate (c) Increased cardiac output (d) Decreased total peripheral resistance (e) Decreased vessel diameter
b and d
Which of the following is/are true regarding neurons: The resting membrane potential is determined by ... (Select all that apply) a. The concentration of anions inside the cell b. The permeability of the cell membrane to different ions c. The concentration of hydrogen ions inside the cell d. The difference in ion concentration between the intracellular and extracellular fluid e. The concentration of neurotransmitter acetylcholine accumulating at the neuromuscular junction
b and d
Select the best answer: Which is/are true regarding the Size Principle? A. The largest motor units will be recruited first because they can generate a more powerful action potential more quickly than smaller motor units B. The smallest motor units will be recruited first because they can generate an action potential sooner C. Motor unit recruitment pattern is progressive based on fiber size D. Motor unit recruitment will occur in the following order: Type I, Type IIa, Type IIx E. Motor unit recruitment will occur in the following order: Type I, Type IIx, Type IIa
b, c and d
A principal function of glycolysis is to
breakdown glucose or glycogen into pyruvate to produce ATP
Depletion of muscle carbohydrate stores during acute exercise can decrease the ability of the muscle to metabolize fat by A. reducing the availability of pyruvate (produced via slow glycolysis), which is an important intermediate for the Krebs Cycle. B. decreasing the rate of muscle lactic acid production. C. reducing the availability of pyruvate (produced via slow glycolysis), which is an important intermediate for the Krebs Cycle. D. increasing the rate of protein metabolism. E. reducing the rate of protein metabolism.
c
Which of the following is true of the change in heart rate during acute exercise? a. the increase in HR is due only to withdrawal of PNS influence b. the increase in HR is due only to increasing SNS influence c. the increase in HR is due to both a PNS withdrawal followed by increasing SNS influence d. the increase in HR is due to both a SNS withdrawal followed by decreasing PNS influence
c
Which statements is/are true regarding the proton pumps found in the ETC? (Select all that apply) a. Each pump moves 4 H+ into the intermembrane space of the mitochondria b. The ETC has 4 proton pumps c. The ETC has 3 proton pumps d. Pumps 1 & 2 move 4 H+ and pump 3 moves 2 H+ into the intermembrane space of the mitochondria e. NADH & FADH2 use pumps 1, 2 and 3 to "pump" H+ (protons)
c and d
How is NAD+ replenished during rapid glycolysis? (Select all that apply) a. FADH2 helps "shuttle" hydrogen ions to the mitochondria of the cell b. via glycogenolysis c. pyruvate accepts hydrogens ions to form lactate d. new NAD+ molecules "appear"
c only
Angiogenesis is the process by which _______ increases. This adaptation helps facilitate improvements in maximal arteriovenous O2 difference following aerobic exercise training.
capillary density
Structural adaptation that helps facilitate increases in maximal (a-v)O2 difference
capillary density
Enzymes ________ reactions by ______ the activation energy.
catalyze; lowering
Vasoconstriction of cutaneous vessels, earlier onset of shivering, and increased release of circulating catecholamines are physiological adaptations that characterize ___________ .
cold acclimatization
The primary function of the Krebs cycle is to
complete the oxidation of substrates to form NADH and FADH2
Heat is transferred from the skin to the surface of cooler objects via direct physical contact
conduction
The Sliding Filament Theory describes what stage of the excitation-contraction coupling (ECC)?
contraction
Describes the ability of a control system (or systems) to maintain homeostatic balance
control system gain
a type of conductive heat loss; heat is transferred directly from the skin to the air or water
convection
The rate-limiting enzyme for the phosphagen system is __________ while __________ is the rate-limiting enzyme for glycolysis.
creatine kinase; phosphofructose kinase
_______ is the rate-limiting enzyme of oxidative phosphorylation
cytochrome oxidase
Variable/factor that is altered or changes in response to another variable
dependent variable
When the ventricles are in systole, the atria are in ________.
diastole
The rate of gas transfer occurs by way of __________ , a process that relies MOST heavily on the __________ .
diffusion; the difference in partial pressure of the gas on either side of the tissue
Which of the following is/are INCORRECT regarding the myocardium? a. It is comprised of single-nucleated cells connected via intercalated discs b. It is under somatic nervous system control c. It does not contain actin and myosin filaments d. a & c e. b & c
e
Which of the following processes is/are responsible for INCREASING in pulmonary ventilation (V) during exercise? a. increased tidal volume b. increased breathing frequency c. increased dead-space ventilation d. a & b e. All the above
e
Motor nerve fibers conduct impulses away from the CNS and are referred to as ___________.
efferent fibers
Outermost layer of skeletal muscle; surrounds muscle belly
epimysium
Heat is transferred from the body to the surrounding environment when water on the skin (sweat) or in the respiratory tract are converted to gas and vaporized
evaporation
Most important methods of heat loss during exercise, especially when exercising in cool temperatures with low relative humidity
evaporation
How does an increase in plasma volume contribute to improved exercise capacity in the heat?
expansion in blood volume enables earlier and higher sweat rate without compromising venous return (stroke volume), which improves cardiac output during exercise
Aerobic production of ATP occurs in the
folds of the inner mitochondrial membrane via oxidative phosphorylation
Energy Systems: NAD+ plays an important role in this anaerobic energy system.
glycolysis
Heart rate variability (HRV) can be used as an indicator of ________. Wide variation in HRV indicates ________ health, while low or little variation is an indicator of ________ health.
health; good; poor
Earlier onset of sweating, higher sweat rate, and vasodilation of cutaneous vessels are physiological responses that characterize ___________ .
heat acclimatization
When the body experiences ____________, the arterial vessels vasodilate, increasing skin blood flow.
heat gain
During _________, the arterial vessels vasoconstrict, decreasing skin blood flow.
heat loss
Blood is returned to the heart via the (select all that apply): i. Aorta ii. Superior & Inferior Vena Cava iii. Right & Left Pulmonary Veins iv. Right Ventricle v. Right & Left Pulmonary Arteries
ii and iii
Several physiological factors contribute to the lactate threshold (LT). Which of the factors listed below do not contribute to the LT? (select all that apply) i. Increased production of lactate ii. High muscle oxygen iii. Accelerated (rapid) glycolysis iv. Recruitment of slow-twitch muscle fibers v. Decreased removal of lactate
ii and iv
Select the best answer: At high environmental temperatures, which of the following variables is/are MOST important in determining evaporative heat loss during exercise? i. radiation ii. relative humidity iii. elevation iv. fitness level v. temperature gradient
ii only
What physiologic adaptation occurs most quickly in response to repeated heat stress?
increase in plasma volume
Variable/factor that is manipulated in an experimental research study
independent variable
Energy Systems: Quantifying the volume of oxygen consumed (VO2) using open-circuit spirometry is an example of this technique.
indirect calorimetry
Energy Systems: We can estimate the energy cost (or amount of energy expended) for a given activity in the laboratory by way of _____________ .
indirect calorimetry
Long-term endurance training adaptation that is responsible for continued increases in VO2 max
maximal (a-v)O2 difference
A motor neuron and all of the muscle fibers it innervates is considered a ________ , and the connecting point between the motor neuron and skeletal muscle is called ________ .
motor unit; the neuromuscular junction
Which layer of the heart is the thickest and is considered the 'heart muscle'?
myocardium
Contains thin, threadlike structures termed myofilaments
myofibril
Arterial blood pressure regulation via the baroreceptors is an example of what type of control system?
negative feedback
When a control system responds by reversing the initial stimulus
negative feedback
The space (or gap) between the motor neuron and sarcolemma
neuromuscular cleft
Release from presnaptic neuron; causes changes in permeability of cell membrane
neurotransmitter
Which of the factors below contribute to the fast portion of EPOC? (Select all that apply) i. Conversion of lactic acid to glucose (gluconeogenesis) ii. Elevated heart rate iii. Elevated blood lactate concentrations iv. Elevated body temperature v. Replenishing of NAD+
none
An action potential is generated when an excitatory stimulus
opens sodium channels, causing the interior of the cell to become more positive
Exercise training considerations such as how to progress the frequency, intensity, volume or "dose" of exercise overtime best characterizes which training principle?
overload
Which training principle describes the physiologic adaptations that occur from repeated bouts of exercise that are performed at a level beyond which it is normally accustomed to?
overload
With prolonged training an individual may notice that their initial improvements begin to plateau or "level off". To see continued training improvements, the ______ principle will be most important to modify.
overload
Carrier molecules NAD+ and FAD+ are in their ________ form, while NADH and FADH2 are in their ________ form.
oxidized; reduced
The lag in oxygen uptake at the onset of exercise is called
oxygen deficit
Connective tissue layer that surrounds individual fascicles
perimysium
Short-term endurance training adaptation that is responsible for increase in EDV
plasma volume
Short-term endurance training adaptation that is responsible for increases in stroke volume
plasma volume
When a control system responds by enhancing the initial stimulus
positive feedback
Neurons are negatively charged on the inside of the cell with respect to the charge on the exterior of the cell. This electrical charge difference is called _____ and is maintained by the _____ at rest.
resting membrane potential; the sodium potassium pump
EPOC is generally higher following heavy (or vigorous intensity) exercise when compared with light exercise because heavy/vigorous exercise
results in greater body heat gained, greater CP depleted, higher blood levels of epinephrine and norepinephrine, and greater depletion of blood and oxygen stores.
smallest contractile unit of the muscle
sarcomere
Intracellular storage site for calcium
sarcoplasmic reticulum
Backflow of blood from the arteries into the ventricles is prevented by
semilunar valves
Biochemical adaptation that alters enzymatic activity to reduce lactic acid formation
shift in LDH isoform to LDH4
Decreased skin blood flow as a result of training in the heat rather than a thermoneutral environment is an example of which training principle?
specificity
Endurance training adaptations include an increase in the number of mitochondria and increased capillary density, while resistance training increases the number of contractile proteins. Differences in aerobic vs. anaerobic training adaptations are explained by the __________ principle.
specificity
To improve exercise capacity at high altitude, in hot ambient temperatures, in zero gravity conditions (i.e., space), etc., individuals must perform exercise training in similar environments. This concept exemplifies which training principle?
specificity
What is/are the major function(s) of the respiratory system?
supply oxygen that is required in metabolism, regulate acid-base balance, and remove carbon dioxide that is produced as a by-product of metabolism
The relationship between oxygen uptake, cardiac output and mixed arteriovenous oxygen content is described mathematically by
the Fick equation
The process of breaking down triglycerides for energy occurs during
the Krebs cycle
What is the primary reason for lactate formation during rapid glycolysis?
the recycle or reform NAD+
Cardiovascular Responses to Exercise: Increases in heart rate at the onset of exercise (up to ~100 bpm) are due to _______ , while further increases in heart rate (beyond 100 bpm) are a result of _______.
vagal withdrawal; increased sympathetic nerve activity
