Kin 492 exam 2 quizzes
Ventilation (V) is increased by increases in both tidal volume (VT) and breathing frequency (f). Which factor contributes more to increases in V during (a) submaximal constant workload exercise vs. (b) incremental exercise at higher intensities?
(a) VT vs. (b) f
Which of the following is/are TRUE regarding afterload (average aortic pressure)?
- High afterload can decrease SV if there is no change to contractility. - Vasodilation of blood vessels to active skeletal muscle(s) can minimize increases in afterload during exercise. - Increases in afterload are unavoidable during exercise due to the redistribution of blood flow and the need to maintain adequate blood pressure.
Which of the following statements is/are true regarding gas exchange at lungs?
- PCO2 is higher in the pulmonary capillaries than the alveoli - PO2 is lower in the pulmonary capillaries than the alveoli - O2 will diffuse from the alveoli to the pulmonary capillaries
Which of the following is true regarding fat metabolism during exercise:
- fatty acids are the predominate fuel during prolonged, lower intensity exercise - fat metabolism is not inhibited by high levels of lactate and insulin
Which of following contribute to the lactate threshold
- low muscle oxygen - accelerated glycolysis - recruitment of fast twitch fibers
Which of the following statements is true regarding the lungs at rest:
- the apex has greater ventilation than blood flow - the base has greater blood flow than ventilation - the base is overperfused - the apex is underperfused
Which of the following statements is/are FALSE regarding the systemic capillaries entering exercising skeletal muscle?
-CO2 content in the systemic capillaries is higher than in the skeletal muscle. -O2 content is higher in the skeletal muscle than in the systemic capillaries.
How does high temperature and low pH of the blood affect the oxyhemoglobin-dissociation curve compared to normal conditions?
-Decreases hemoglobin's affinity for oxygen independent of the partial pressure of oxygen. -Causes a rightward and downward shift in the sigmoidal curve that favors unloading of oxygen
The rate of gas transfer (Vgas) in the lungs 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 statements is/are TRUE regarding mean arterial pressure (MAP)?
-Increases in cardiac output (Q) or heart rate (HR) will increase MAP. - MAP can be estimated from systolic and diastolic BP measured in the brachial artery.
Which of the following is/are INCORRECT regarding the myocardium:
-It is under somatic nervous system control -It does not contain actin and myosin filaments
Describe the trends observed in muscle stores of phosphocreatine (PCr) and ATP production from anaerobic vs. aerobic pathways during the first 3-5 min of constant-load, submaximal (moderate intensity) exercise, transitioning from rest to steady-state.
-PCr muscle stores decline -PCr ATP production declines -glycolysis ATP production increases until 2-3 min, then declines -aerobic ATP production increases steadily before leveling off
What is/are the major function(s) of the respiratory system?
-Supply oxygen that is required in metabolism -Regulate acid-base balance -remove carbon dioxide that is produced as a by-product of metabolism
All of the following is/are FALSE regarding the ventilatory threshold (Tvent) EXCEPT:
-The Tvent occurs with incremental, high intensity exercise beyond 50-75% of VO2max for trained/elite athletes. -The Tvent is characterized by increasing partial pressures of carbon dioxide with increasing exercise intensity, despite increases in ventilation.
The muscular arterioles are called "resistance vessels" - why?
-They contain the greatest amount of smooth muscle -They have the smallest vessel diameter of those arranged in series -Their primary role is regulating blood flow
Select the statement (or statements) that accurately describes the actions of the atria vs. ventricles during the cardiac cycle. (Remember, select the best answer).
-When the ventricles are in systole, the atria are in diastole. -When atrial contraction occurs, the ventricles relaxed and filling.
Heart rate variability (HRV) is defined as the ________ and it can be used as a indicator one one's ________.
-beat-to-beat changes in HR that occur during a single cardiac cycle - health
Using the Fick Equation as your reference, which of the following factors DIRECTLY determines the rate of oxygen uptake and utility?
-cardiac output -mixed arteriovenous blood oxygen content difference
Which of the following processes is/are responsible for INCREASING pulmonary ventilation (V) during exercise?
-increased tidal volume -increases breathing frequency
Which of the following is/are true regarding the INSPIRATORY phase of ventilation:
-intrapulmonary pressure decreases -the diaphragm contracts & moves downward in the thoracic cavity
___ are located in the atria, while ___ are located in the ventricle, specifically the ___
-pacemaker conduction cells - contractile myocytes - myocardium of left ventricle
Based on the graph below, what is happening physiologically at the arrow?
-the individual has reached their lactate threshold -The individual is experiencing an alinear rise in their blood lactate concentration.
increases in alveolar ventilation (VA) suggest that...
-there is a greater volume of air (L/min) reaching the respiratory zone. - there is a greater volume of air (L/min) available for gas exchange at the alveoli.
Maximal oxygen uptake ( O2max) is defined as the physiologic ceiling for the
-uptake of oxygen into the lungs -delivery of oxygen to the muscles -ability of skeletal muscle to extract and use oxygen to for energy
Which of the following is correct in terms of explaining why mean arterial pressure (MAP) and heart rate (HR) responses are HIGHER during constant workload exercise performed with the upper body (i.e., arm cycle ergometer) compared to the lower body (i.e., leg cycle ergometer)?
Blood is redistributed away from less metabolically active tissue to the active skeletal muscle tissue by vasoconstriction of arteries to the legs vs. the arms, resulting in greater total peripheral resistance (TPR), MAP and HR responses.
Which of the following statements (in its entirety) is MOST accurate in describing the relationship between ventilation and perfusion in the lungs AT REST?
There is greater ventilation than perfusion at the apex of the lung, which is indicated by a V/Q ratio > 1.0
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 of them occur as a result of increased left ventricular EDV
The heart is comprised of 4 chambers, 2 types of cardiac muscle cells, and although it is considered "one pump", it really encompasses 3 different pumps to the various circulations, i.e., venous, pulmonary, and systemic circulations.
false
The left 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
The partial pressure of O2 at the lung is high, favoring the formation of "deoxyhemoglobin" (i.e., O2 is unloaded at the lungs).
false
The partial pressure of O2 at the tissues (skeletal muscle) is high, favoring the formation of "oxyhemoglobin" (i.e., O2 is loaded at the tissues).
false
True/ False: The Frank-Starling mechanism of the heart increases stroke volume by way of increased End Systolic Volume (ESV).
false
True/False: As constant-load, submaximal exercise continues for a prolonged period of time (>20 min), a gradual decrease in heart rate occurs as a result of increased stroke volume due to enhanced skin blood flow.
false
During incremental exercise fuel selection switches from
fats as primary substrate to carbs
During incremental exercise, fuel selection switches from ______ as the primary substrate to ______ .
fats to carbohydrates
There is greater unloading of oxygen at the tissues when blood temperatures exceed 37 degrees or blood pH levels are less than 7.4 why?
hemoglobin has a decreased affinity for oxygen
Myoglobin has a _____ affinity for oxygen than hemoglobin, even at _____ of oxygen.
higher lower partial pressure
What factor is the primary reason we observe an upward drift in ventilation during prolonged, constant-load submaximal exercise (>20/30 min) in a hot and/or humid environment?
increase in blood temperature
How is ventilation increased during exercise?
increase in tidal volume and breathing frequency
During EXPIRATION, intrapulmonary pressure (P) ...
increases; becomes greater than the P of air outside of the body
The lactate threshold (LT) is observed during ________ exercise and occurs at intensities of ________ for untrained individuals vs. ________ for trained individuals.
incremental 50-60% of VO2max >60-80% of VO2max
Which of the following represents the body's first line of defense for maintaining acid-base balance during exercise?
intracellular buffering systems hydrogen ion transporters
during inspiration
intrapulmonary pressure is less than atmospheric pressure
EPOC is generally higher following heavy (or vigorous intensity) exercise compared to low (or light intensity) exercise because ...
it results in greater body heat storage, greater lactic acid accumulation, greater phosphocreatine depletion, higher blood levels of epinephrine and norepinephrine, and greater depletion of blood and muscle oxygen stores.
Jenny's lungs have an intrapulmonary pressure of 755 mmHg and an intrapleural pressure of 751 mmHg. Atmospheric pressure is 759 mmHg. What is happening to Jenny?
jenny is inhaling
Jenny's lungs have an intrapulmonary pressure of 759 mmHg and an intrapleural pressure of 755 mmHg. Atmospheric pressure is 759 mmHg. What is happening to Jenny?
jenny is suffocating
______ is the preferred muscle fuel source during short duration + high-intensity exercise, while ______ is the preferred muscle fuel source during long duration + low-moderate intensity exercise.
muscle glycogen plasma free-fatty acids
The lag in oxygen uptake at the onset of exercise is called...
oxygen deficit
What is the generally well accepted value, expressed relative to body size, used to quantify the amount of energy we expend at rest?
oxygen uptake value of 3.5 ml/kg/min
Based on the figure below, which of the following options correctly identifies the action potentials depicted in images A, B, and C?
pacemaker-conduction cell (A); skeletal muscle cell (B); contractile myocyte (C)
There are two types of cardiac cells in the heart: _____ are located in the atria (nodal tissue) while _____ are located in the ventricles, with a greater amount in the _____.
pacemaker-conduction cells contractile myocytes myocardium of the left ventricle
Which of the following BEST describes cardiovascular responses to INCREMENTAL EXERCISE?
q increases until maximal effort is reached; HR increases linearly in proportion to exercise intensity; SV increases initially before plateauing at 40% of maximal oxygen uptake.
Which factor is the MOST influential when discussing resistance to blood flow?
radius of blood vessel
Which factor is most influential in determining resistance to blood flow and what effect does it have on stroke volume
radius of the blood vessel decrease stroke volume
Replace oxygen stores in the blood and muscle.
rapid EPOC
Replenish muscle stores of phosphocreatine (PCr)
rapid EPOC
Depletion of muscle carbohydrate stores during acute exercise can decrease the ability of the muscle to metabolize fat by ...
reducing the availability of pyruvate (produced via slow glycolysis), which is an important intermediate for the Krebs Cycle.
The respiratory system regulates blood acid base balance during exercise primary by...
removing H and co from the blood via the bicarboate buffering system
Which of the following contains mixed arteriovenous deoxygenated blood:
right ventricle
Backflow of blood from the arteries into the ventricles is prevented by
semilunar valves
Which of the following mechanisms is/are responsible in assisting blood return to the heart?
skeletal muscle pump respiratory pump
Which of the following mechanisms is responsible for returning blood to the heart during exercise
skeletal muscle pump one way valves
Clearance (removal) of lactate
slow EPOC
Gradual decrease in heart rate and core temperature
slow EPOC
At rest and during exercise, the PRIMARY FACTOR that contributes to resistance of airflow in the pulmonary system is/are ______________.
the diameter of the airway
The relationship between oxygen uptake, cardiac output, and mixed arteriovenous blood oxygen content is described mathematically by
the fick equation
The oxyhemoglobin dissociation curve describes...
the relationship between partial pressure of O2 in the blood and hemoglobin's affinity for O2.
The lactate threshold is the point at which...
there is a dramatic alinear increase in blood lactate concentration during incremental exercise
The lactate threshold is the point at which:
there is a dramatic alinear increase in blood lactate concentration during incremental exercise
(a− )O2 difference describes the amount of O2 that is taken up by the tissues from arterial blood.
true
(a− )O2 difference will increase during exercise due to the increased metabolic demand and higher oxygen uptake in skeletal muscle.
true
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
Hemoglobin is contained in erythrocytes and each hemoglobin can bind up to 4 molecules of oxygen.
true
It describes the quantitative relationship between partial pressure of oxygen and hemoglobin's affinity for oxygen.
true
Redistribution of blood flow during exercise is achieved by vasodilation of blood vessels to active tissues and vasoconstriction of blood vessels to inactive tissues.
true
The (1) partial pressure of O2 and (2) affinity of hemoglobin for O2 determines whether the reaction will favor the formation of oxyhemoglobin or deoxyhemoglobin.
true
The ___ contains the greatest amount of ___ which enables arterioles to regulate blood flow via vasoconstriction and vasodilation
tunica media smooth muscle
The ________ of arterioles contains the greatest amount of ________ , which is used for regulating blood flow via vasoconstriction and vasodilation.
tunica media smooth muscle
Increases in HR at the onset of exercise (up to ~100 beats/min) are due to _______ , while further increases in HR (beyond 100 beats/min) are a result of _______.
vagal withdrawal increased sympathetic nerve activity
There is a 0.13 second delay once the electrical impulse reaches the atrioventricular (AV) node to allow for
ventricles to fill with blood
The frank starling mechanism describes the way by which stroke volume in increased via reduction in end diastolic volume
false
Several physiological factors contribute to the lactate threshold (LT). Which of the factors listed below DO NOT contribute to the LT?
-high muscle oxygen -Recruitment of slow-twitch muscle fibers
During INCREMENTAL exercise, pulmonary ventilation results in a linear increase in ventilation up to approximately _________ of VO2max, beyond which there is a/an _________ rise.
50-75% alinear
During pulmonary gas exchange, O2 diffuses from the ________ into the _________, while CO2 diffuses from the _______ into the ______ .
Alveoli; capillary blood capillary blood; alveoli
The amount of blood left in the ventricles of the heart after the end of the contraction phase is called:
End systolic volume.
In terms of acid-base balance in the blood, which of the following could result from hypoventilation or breath holding?
Increase in arterial PCO2/H+ concentration, decrease in arterial PO2, decrease in arterial blood pH
What effect does the Frank-Starling mechanism have on stroke volume (SV)? Your answer should also include the correct physiological explanation of the observed effect.
Increases SV; indirect effect on contractility caused by increased mechanical stress (stretch) on ventricular wall resulting from increased end-diastolic volume (EDV)
Which of the following statements is/are TRUE regarding the effect of ventilation on acid-base balance?
Increases in ventilation = decreases the partial pressure of carbon dioxide and maintains blood pH.
Replenishing skeletal muscle stores of calcium.
Not part of EPOC
Calculate cardiac output (Q) for an individual with an heart rate of 64 beats/min and a stroke volume of 70 mL of blood. Using this same individual: What would their end systolic volume (ESV) be if they have an end-diastolic volume (EDV) of 130 mL of blood?
Q = 4.48 L/min ESV = 60 mL
Which of the following mechanisms is/ are responsible for returning blood to the heart during exercise?
Skeletal muscle pump and one way valves in the veins
The Fick equation states that __________ , meaning that either an __________ or __________ would result in increased oxygen uptake.
Vo2= q x a-vo2 diff increase in Q increase in mixed arteriovenous blood o2 difference
The action potential of a contractile myocyte is distinct due to the long refractory period (or plateau) caused by a delayed influx of extracellular potassium into the cell.
false
The ________ buffer system is considered the most important buffer system in the body.
bicarbonate
Which of the following accurately reflects the most common extracellular buffering system in the body that maintains acid-balance balance via removal of CO2 at the lungs?
bicarbonate recombines with hydrogen at the lung to form carbonic acid, this dissociates into carbon dioxide and water that we "blow off" at the lung
Based on the image below, which of the following correctly identifies repolarization of the ventricles?
c-t wave
Blood flow during exercise is controlled (or regulated) by the metabolic requirements of skeletal tissue, which is detected by the baroreceptors and relayed to the cardiovascular control center in the brain.
false
Cardiovascular drift is observed during prolonged, constant-load exercise and is characterized by a gradual decrease in HR and gradual increase in SV, while is maintained.
false
Hemoglobin and oxygen form an irreversible bond to form "oxyhemoglobin".
false
Isovolumic contraction occurs at the end of ventricular systole.
false
Nitric oxide is a potent vasoconstrictor secreted by the endothelium.
false
SV, HR and (a− )O2 difference will increase linearly with exercise intensity until vo2 max is reached.
false
The Cori Cycle is a process by which lactate is converted to plasma fatty acids in the liver.
false
At an RER of 0.95, which of the following fuel sources are being utilized the MOST to produce ATP?
carbohydrates
Which of the following is/are considered a central component of vo2? (select all that apply)
cardiac output stroke volume
If atmospheric pressure is less than intrapulmonary pressure..
expiration
(a− )O2 difference is considered a central component.
false
According to Fick's law of diffusion, the rate of gas transfer will increase if the cross sectional area of tissue increases or if thickness of tissue increases
false
