Exphys lecture exam 4 - Cardiovascular

VO2

- Absolute VO2 (L/min) - Relative VO2 (ml/kg x min) *typically 3.5

Boyles Law

- Air moves from high pressure to low pressure - Increase in volume of lungs = decrease of pressure - Decrease in volume of lungs = increase in pressure

external respiration

- exchange of gases between lungs and blood in alveolar capillaries - transport of blood to and from systemic tissues - exchange between systemic capillaries and systemic tissues

If your subject's cardiac output was 7 liters per minute and their heart rate was 100 beats per minute and their end systolic volume was 60 milliliters, then their end diastolic volume would be how many milliliters?

130

intraplueral pressure

756 mm Hg

intra-alveolar pressure

760 mmHg - keeps our lung from collapsing because of surfactant and negative pressure in the pleural sac

If your subject's blood pressure was 112/82 then their mean arterial pressure would be ___.

92

Spirometry

A was to study lung function - can value lung volumes

Forced vital capacity

Amount of air able to force out - healthy subject should be able to move 80%

Pulmonary Ventilation

Amount of air moved by the lungs per minute VE = TV x RR - At rest is typically 6-10 L/min

Tidal Volume

Amount of air moved in and out per normal breath - 500 ml

Residual volume

Amount of air that cannot be expelled and always resides - 1200 ml

Expiratory reserve volume

Blowing out as much air as possible - 1000 ml - lowest point being 1200 ml

Anatomical dead space

Duct work of the lungs that does not take part in gas exchange

Physiological/alveolar deadspace

Lack of blood flow or capillaries to areas that could take part in exchange - VA = (TV - dead space) x RR

Diaphragm

Moves downwards to increase size of thoracic cavity

Restricted pulmonary disease

Related to restricted ability to expand the lungs - Loss of elasticity, pulmonary fibrosis - Smaller IRV, ERV, etc. - If VC is less that 80% this is an indicator

intrapleural space

Space between the two membranes, visceral pleura and parietal pleura, that cover the lungs. - 4 mmHg - also called transmural pressure

Which is better to increase, TV or RR?

TV

inspiratory reserve volume

Taking in as much air as possible - 3000 ml - peak of 5700 ml

simple subtraction/addition problem with lung volumes and capacities: If your subject has a TLC of 5L, an IC of 2.5L, and an RV of 1 L, which of the following is/are true? (I recommend drawing a spirograph like the one in figure 10-9 of your text on p 223to help with your answer

The ERV is 1.5L b The FRC is 2.5L c The VC is 4L d All of the above ARE true e only two of the above ARE true

Which of the following is/are NOT true about partial pressures of oxygen (PO2)?

The PO2 of the atmosphere at sea level is approximately 160 mmHg (760 x 21%O2) b Because fresh air (from atmosphere) mixes with air already in the lungs during inspiration, the PO2 in the alveoli is LOWER than the PO2 in the atmosphere c The PO2 of the blood in the pulmonary vein is usually higher than the blood in the systemic arteries d a common value for the PO2 of the blood leaving the systemic capillaries is around 40 mmHg e Three of the above

If your subject's heart rate was 100 bpm, their EDV was 150 ml and their ESV was 50ml, then which of the following would be true?

Their Stroke Volume would be 100ml b Their Ejection Fraction would be 67% c Their Cardiac Output would be 10 L/min d All of the above e Only two of the above

The activity of the respiratory (or abdominal thoracic) pump would increase ---------- ---------, which would increase end diastolic volume, which would increase stroke volume, which would increase cardiac output.

Venous Return

External intercostals

Work by raising ribs and increasing size of rib cage

Capacities

Write down

The following depicts resting pressure-volume loops (solid lines). In which figure does the dashed line best represent the pressure-volume loop during aerobic exercise in a young healthy subject?

a A (both taller and wider) b B c C d D e None of the above

Which of the following would NOT increase muscle blood flow?

a An increase in arterial pressure b A decrease in perfusion pressure c An increase in arteriole radius in the muscle d A decrease in resistance in the blood vessels in the muscle e three of the above

In class we discussed a study that looked at the blood pressure response to heavy resistance exercise among elite power lifters. Which of the following were NOT among its findings?

a Blood pressure reached around 480/350 in one subject b The increases in blood pressure were partly due to sympathetically-mediated constriction of arterioles in the active muscles c The increases in blood pressure were partly due to mechanical compression of blood vessels in the active muscles d The increases in blood pressure were partly due to the Valsalva maneuver e Two of the above

In class (or lecture video) I described an experiment that looked at arm and leg blood flow and other variables during leg exercise and combined arm+leg exercise. Which of the following is/are NOT true about this experiment, its findings, and these results suggest?

a Cardiac output was higher with arm+leg exercise than leg exercise alone b leg blood flow was lower during arm+leg exercise than during leg exercise alone c VO2 was higher during arm+leg exercise than during leg exercise alone d The results suggested that the subjects experienced a relative vasoconstriction in the leg muscles during combined arm+leg exercise compared to leg only exercise e the results of this study suggest that the pumping capacity of the heart is what limits maximal blood flow f All of the above ARE true g Two of the above

If your subject's blood pressure was 132/78 then

a Current guidelines (after Nov 2017) would classify this person as having elevated blood pressure b Old guidelines (pre Nov 2017) we would say this subject had hypertension c Current guidelines (after Nov 2017) would classify this person as having hypertension d Current guidelines (after Nov 2017) would classify this person as having pre-hypertension e Current guidelines (after Nov 2017) would classify this person as having normal blood pressure f none of the above

Comparing the blood pressure of a healthy young subject response during isometric and aerobic exercise involving the legs, which of the following is/are NOT true?

a DBP would tend to increase during isometric exercise due to mechanical compression of blood vessels b The SBP would be higher during isometric than during aerobic exercise c MAP would tend to be higher during isometric exercise d The Pulse Pressures would tend to be higher during isometric exercise e Three of the above

Which of the following is/are true about changes in total peripheral resistance during exercise?

a During aerobic activities TPR increases b during aerobic exericse local factors in the active muscles cause vasodilation and decrease resistance even though the sympathetic nervous system is trying to cause vasoconstriction (this is called sympatholysis) c the sympathetic nervous system causes widespread vasodilation during exercise d During isometric exercise with a heavy weight TPR would decrease e An increase in TPR would mean that there would be greater systemic vascular conductance (SVC) f All of the above g None of the above

Which of the following is/are true about autonomic control of heart rate (HR) during exercise?

a During the transition from rest to exercise, much of the increase in HR would be associated with a decrease in acetylcholine acting on the SA Node b Most ofthe increase in HR up to about 100bpm would be associated with a decrease in vagus nerve activity c much of the increase in HR above 100 bpm would be associated with an increase in norepinephrine acting on the SA Node d much of the increase in HR above 100 bpm would be associated with an increase in sympathetic nervous system activity e maximum heart rate would be lower if a subejct was given a beta blocker f all of the above are ture g only two of the above

While exercise training reduces cardiac risk, there is an increase in cardiac risk (risk of serious arrhythmia and/or sudden cardiac death) during and immediately following a bout of exercise. Which of the following is/are NOT true about this?

a Exercise training may reduce the risk of serious arrhythmias, in part, by increasing parasympathetic and decreasing sympathetic tone to the heart b During an acute bout of exercise there is greater risk of myocardial ischemia due to an increase in the heart's oxygen needs; this increases the liklihood of ventricular arrhythmias c during exercise there is a greater risk of ventricular arrhythmias, in part, due to changes in Na+/K+ balance d Immediately after exercise, a cessation of the muscle pump may reduce blood pressure; this may reduce coronary blood flow e If myocardial ishemia occurs during, or following, exercise, this might alter conduction velocity and depolarization f the elevation in circulating catecholamines enhances the possilbity of ventricular arrhythmmias during exercise g Atherosclerosis is the number one cause of sudden cardiac death during exercise in young subjects h Three of the above

The drive for the cardiovascular control centers in the medulla to make cardiovascular (CV) responses to exercise (increase HR, MAP, etc) comes from multiple loctions except for the following:

a Higher brain centers; which may increase cardiovascular drive even prior to the start of exercise b Baroreceptors, which are set to a higher pressure during exercise such that normal blood pressures seem too low; this helps to fine tune the CV response to exercise c Group III and IV afferents in skeletal muscle which detect chemical changes in the muscle when it is active; this helps to fine tune the CV response to exercise d arterial chemoreceptors which detect a decrease in pO2 in the arterial blood at the onset of exercise, this helps to initiate the CV drive at the onset of exercise e All of the above f Two of the above

On this picture of the heart's electrical conduction system, which label is incorrect?

a Interatrial pathway b Internodal pathway c sinoatrial node d Left Bundle Branch e three of the above

Which of the following is/are true about this figure?

a It illustrates the Frank-Starling Law of the heart b The X axis is EDV c the Y axis is Stroke Volume d If the middle, blue, line represents a normal curve, then the top, green line, depicts what happens to inotropy with sympathetic stimulation e all of the above f only two of the above are true

Which of the following is/are true about the heart rate (HR) response to exercise?

a Max HR would be higher during arm crank exercise than cycling exerrcise b HRmax would be higher after training than before training c HR at 100 Watts would be higher during arm crank than during cycling exercise d HR at 100 W on a cylce ergometer would be higher in a trained subect than in an untrained subject e all of the above ARE true f Three of the above

Blood pressure (BP) following exercise:

a May remain low for several hours; this is called post-exercise hypotension b May remain elevated for up to several hours following exercise in young healthy subjects; this is called post-exercise hypertennsion c The BP changes following aerobic exercise because of histamine release during exercise, which increases systemic vascular conductance d The BP changes following resistance exercise are due to increases in cardiac output AND decreases in systemic vascular conductance e A & C f B & D

Which of the following is/are NOT true about the stroke volume (SV) response to exercise?

a Most of the increase in SV during aerobic exercise is associated with an increase in EDV b Most of the increase in SV during aerobic exercise is associated with an increase in venous return c An increase in muscle activity would increase venous return, which would increase EDV, which would increase SV d An increase in ESV during exercise would increase SV e The sympathetic nervous system would increase contractiilty, which would increase SV f In a normal subject it would not be uncommon to have SV increase from 70ml at rest to 120 ml per beat at maximal exercise g Maximal SV would be higher during cyling than during arm crank exercise h All of the above ARE true i Three of the above

Review Which of the following statements is/are NOT true regarding this figure?

a Phase U would be associated with ejection of blood from the ventricle b Phase P would be associated with filling of the ventricle c The stroke volume would be 60ml d The ejection fraction would be over 50% e All of the above ARE true f Two of the above

There are notable changes in blood volume, erythrocyte volume, plasma volume, and hematocrit with exercise training; which of the following is/are NOT true?

a Plasma volume increases during training b Erythrocyte volume increases during training c Blood volume increases during training d The initial increase in blood volume with training is associated mostly with an increases in erythrocyte volume e in the early stage of training it is common to see a reduction in hematocrit and hemoglobin concentration; this is sometimes called athletic anemia f Because of their extreme training elite athletes often have such a large increase in plasma volume that their hematocrit is lower than in untrained subjects g the increase in blood volume contributes to the enhanced venous return and stroke volume in trained subjects h All of the above ARE true i Three of the above

The ----------- is/are a part of the heart's electrical conduction system that causes a brief delay between atrial and ventricular depolarization. This is important because --------.

a SA Node, otherwise the heart rate could get too fast b AV Node, it allows the ventricles to finish emptying before they start to fill c AV Node, it allows the ventricles to finish filling before they begin to contract d Bundle Branches, they ensures that the impulse will spread rapidly through the ventricles

Which of the following is/are NOT true about how the autonomic nervous system influences cardiac output? SNS = sympathetic nervous system, PNS = parasympathetic nervous system, HR = heart rate, SV = stroke volume, EDV = end diastolic volume, VR = venous return.

a SNS increases HR , which would tend to increase Q b SNS increases cardiac contractility, which would increase SV and Q c SNS causes constriction of veins, which increases VR and EDV, which increases SV and Q d PNS slows HR and decreases Q e SNS causes constriction of arteries, which increases VR, and thus increses Q f PNS weakens ventricular contraction, which decreaes SV and Q g PNS dilates veins, which decreases VR, which decreases EDV, SV and Q h A, B, and C i E, G, and F

TPR during exercise: which of the following is/are true?

a Sympathetic NS would tend to cause an increase in TPR b local metabolic factors cause dilation and decrease TPR in active tissues c TPR would be lower during cycling than arm cranking d all of the above ARE true

Students are typically aware that many of the cardiovascular adjustments to exercise occur to facilitate an support cellular aerobic metabolism and increasing whole body oxygen consumption. Which of the following statements are true about the connection between the cardiovascular system and oxygen consumption?

a The Fick formula explains how cardiac output is related to oxygen consumption b VO2 = Q x a-vO2difference c oxygen consumption increases if we increasee cardiac output d VO2 will increase if we increase oxygen extraction from the blood by the systemic tissues (including muscles) e all of the above

Which of the following is/are NOT true about the heart's energy and and oxygen requirements

a The heart is such an aerobic organ that it is more likely to consume lactate as a fuel than to make lactate b The heart's oxygen demand can be estimated by the formula HR x SBP, which is called the Double Product or Rate Pressure Product c The heart's oxygen demand increases approximately 2-fold between rest and maximal exercise in young, healthy subjects d While the heart's oxygen needs increase substantially duirng exercise, there is a large reduction in the time for coronary blood flow during exercise because coronary flow occurs mostly during diastole e Increasaes in coronary blood flow are so important during exercise because the heart is usually already extracting so much of the oxygen delivered to it f All of the above ARE true g Three of the above

Which of the following is/are NOT true about the stroke volume response to aerobic exercises like cycling and running?

a The increase in stroke volume during exercise is due, in part to increases in EDV b The increase in stroke volume during exercise is due, in part to increases in ESV c The increase in stroke volume during exercise is due, in part to increases in venous return d The increase in stroke volume during exercise is due, in part to increases in the activity of the muscle pump e All of the above ARE tru

Understanding changes in intrapleural, intra-alveolar, and transmutation pressure are critical for understanding the respiratory cycle, which of the following is NOT true about these pressures?

a The intra-alveolar pressure decreases during inspiration b The intrapleural pressure is always lower than the intra-alveolar pressure; except in the case of a pneumothorax c Before inspiration, the intra-alveolar and atmospheric pressures are temporarily equal d When the diaphragm contracts, it pulls on the pleural sac, this increases the volume of the pleural sac, which decreases the intrapleural pressure e All of the above ARE true

How would wiggers diagram be different during aerobic exercise?

a The peak aortic and ventricular pressures would be higher (than the 120 indicated in the figure) during the ejection period b the duration of both systole and diastole would be shorter, but the duration of diastole would decrease more than the duration of systole c The end diastolic volume would be higher than the 130 recorded on this figgure d the end systolic volume might be a little lower than the 65 indicated on this figure e the ventricles would fill faster than indicated on this figure f all of the above g two of the above

Not all of the air entering the lungs each minute participates in gas exchange; which of the following is/are NOT true?

a The term anatomic dead space refers to the volume of air in the airways b The alveolar ventilation provides a better indication of the amount of air participating in gas exchange than the pulmonary ventilation c If your goal was to increase gas exchange, it would be more effective to increase respiratory rate than to increase tidal volume d All of the above ARE true e All of the above are NOT true

The SA Node normally serves as the pacemaker of the heart. Which of the following is/are true about the electrical activity of these pacemaker cells

a They begin to depolarize as soon as they repolarize b The pacemaker cells begin to depolarize, in part, due to sodium leaking in c Once the pacemaker cells start to depolarize, the permeability to calcium increases, causing further depolarization d The depolarization phase of their action potential is associated with an influx of calcium, not sodium like most other electrically excitable cells e All of the above are true f None of the above are true

Which of the following are NOT true about changes in stroke volume (SV) with endurance training?

a Training increases maximal stroke volume b An increase in blood volume contributes to the increase in maximal stroke volume by increasing venous return and EDV c Endurance training increases left ventricular volume, which increases the maximal EDV and SV d Training may increase relaxation rate of ventricular muscle cells so that at any given heart rate there is more filling time e All of above f three of the above

The pulmonary response to constant intensity exercise includes all of the following EXCEPT:

a a rise in ventilation prior to the onset of activity b a very slow and gradual rise in ventilation after the start of exercise c reaching a relatively steady value during low and moderate intensity exercise d a continuous increase in ventilation during high intensity exercise even though it may be constant e Three of the above

Which of the following is/are true?

a acetylcholine slows heart rate b acetylcholine binds with muscarinic cholinergic receptors on the heart c acetylcholine has a negative chronotropic effect on the heart d all of the above e two of the above

which of the following would increase quadriceps blood flow?

a an increase in femoral artery pressure b a decrease in femoral vein pressure c an increase in perfusion pressure d vasodilation in quadriceps arterioles e all of the above f only two of the above

During an ACUTE BOUT of exercise, which of the following would NOT be expected to increase EDV and SV?

a an increase in muscle pump activity b an increase in afterload c an increase in preload d an increase in activity of the respiratory pump (ventilation) e sympathetically mediated venoconstriction f an increase in blood volume g all of the above WOULD increase EDV h two of the above

Emphysema and chronic bronchitis:

a are two pulmonary diseases categorized as COPD b are associated with increased airway resistance c are associated with reduced flow rates d All of the above

The sympathetic nervous system can cause constriction of arteries & arterioles, and also of veins. In all cases, constriction would tend to increase blood pressure, but constriction in these different parts of the circulation increase blood pressure by different mechanisms. Constriction of -------------- would be expected to increase venous return, which would increase end diastolic volume, which would increase stroke volume, which would increase cardiac output, which would increase mean arterial pressure.

a arteries b arterioles c veins d A and B e all of the above

The sympathetic nervous system can cause constriction of arteries & arterioles, and also of veins. In all cases, constriction would tend to increase blood pressure, but constriction in these different parts of the circulation increase blood pressure by different mechanisms. Constriction of ---------- would increase total peripheral resistance which would increase mean arterial pressure. Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer.

a arterioles b venules c veins d vena cava e two of the above

among the blood vessels:

a arterioles are the resistance vessels b arteries serve as a pressure reservoir c veins are capacitance vessels (serve as a volume reservoir) d all of the above e only two of the above

Which of the following is/are NOT true about a-vO2 difference and its response to exercise?

a at rest it is usually close to 5 vols% b it usually increases during exercise mostly due to increases in arterial oxygen content c it usually increases during exercise mostly due to decreases in venous oxygen content d a common maximal value would be 15 vols% e two of the above are NOT true

In class I described an experiment where a blood pressure cuff could be inflated during or at the end of forearm exercise and that this would slow the recovery of heart rate and blood pressure after exercise. This type of experiment has been used to study the role of the -----reflex in regulating the cardiovascular response to exercise. This reflex is initiated by group III and IV afferents in the active muscle and they send signals about the metabolic status of the muscle, which is important for the perception of effort, and also helps to match the metabolic demands of the activity with the cardiovascular and pulmonary responses to exercise.

a baro b cold pressor c muscle pressor d chemo e orthostatic f diving g occulocardiac h None of the above

Which of the following respiratory muscles are correctly matched with the phase or respiration?

a diaphragm: expiration b internal intercostals: inspiration c external intercostals: expiration d scalenus: expiration e abdominal muscles: expiration f Three of the above g None of the above

Which of the following is/are NOT true about the blood pressure response to exercise?

a during cycling we would expect systolic blood pressure to increase b in young healthy subjects during large muscle mass aerobic exercises (like cylcing) we would expect diastolic blood pressure to increase c we would expect mean artieral pressures to be higher during isometric knee extensions than during cycling d we would expect diastolic blood pressure to increase during resistance exercise e three of the above f all of the above ARE true

What are true about the cardiac muscle cell action potential?

a during phase Y, there would be an Ca2+ influx b during phase Y, there would be a K+ influx c during phase Z, there would be a K+ efflux d A & B e A & C f None of the above

Calcium is critical for signalling contraction in all types of muscle. What is true about calcium regulation in cardiac muscle and skeletal muscle

a in skeletal muscle calcium is released from the SR by ryanodine receptors b in cardiac muscle calcium is released from the SR by ryanodine receptors c in skeletal muslce, thy dihydropyridine receptors work as a voltage sensor d in cardiac muslce, thy dihydropyridine receptors work as a calcium channels e in skeletal muscle, essentially all of the calcium signalling contraction is from the SR, In cardiac muscle, some of the calcium comes from the SR and some from the ECF f all of the above are true g only 4 of the above are true

The muscle pump:

a increases venous return, which would be expected to increase EDV and SV b decreases venous pressure immediately after contraction, which increases muscle blood flow c can increase perfusion pressure during exercise even if arterial pressure stays the same d All of the above e A & B

Which of the following is/are true about a-vO2 difference and its response to exercise?

a it is usually reported in percent saturation b it usually increases during exercise MOSTLY due to increases in arterial oxygen content c it usually increases during exercise mostly due to decreases in venous oxygen content d a leftward shift in hemoglobin's oxygen dissociation curve would tend to increase it e two of the above

Which of the following is/are true about CO2 transport in the circulation

a most of the CO2 transported in the circulation is bound to hemoglobin b most of the CO2 transported in the circulation is in the form of bicarbonate c most of the CO2 transported in the circulation is physically disolved d high levels of CO2 in the arterial blood is called hyperoxia e high levels of CO2 in the arterial blood is called hypercapnia f A & D g B & E

The blood pressure (BP) response to isometric and resistance exercise is in some ways similar, but also at least a little different from the BP response to aerobic/dynamic exercise. Which of the following are true about these BP differences/similarities between dynamic and isometric/resistance exercise ?

a systolic blood pressure increases in both resistance and aerobic exercise b in aerobic exercise DBP decreases due to vasodilation in the active muscles c in resistance exercise DBP increases due to increases in TPR d mean pressures tend to be higher during isometric exercise than during aerobic excercise e all of the above f two of the above

Which of the following is/are true about the bicarbonate buffering system?

a the enzyme carbonic anhydrase catalyzes the interconversion between CO2 + H2O and carbonic acid b in the tissues, CO2 and water form carbonic acid, which then forms H+ and HCO3- c Over 60% of CO2 transport from the tissues to the lungs is in the form of bicarbonate d in the lungs, where pCO2 is lower, the reaction favors the production of CO2 and H2O e when body fluids become acidic during intense exercise this system allows us to buffer the blood by blowing off extra CO2 f all of the above g only two of the above are true

During the period of isovolumetric ventricular contraction:

a the pressure in the atria is lower than the pressure in the ventricle b the pressure in the aorta is higher than the pressure in the ventricle c the mitral valve is closed d the aortic semilunar valve is closed e all of the above f two of the above

Which of the following labels is/are NOT true?

a this subject's end systolic volume is 55ml b this subject's stroke volume is 60 ml c 130 mmHg would be a reasonable number for this subject's systolic blood presure d this subject's ejection fraction is over 50% e all of the above ARE true f two of the above

Which of the following is/are NOT true about cardiac drift?

a this term relates to the gradual increase in heart rate (HR) over time during a constant intensity exercise bout b HR must increase to maintain cardiac output (Q) as stroke volume (SV) decreases c an increase in HR may contribute to the decrease in SV d a loss of plasma volume contributes to the decrease in SV e an increase in cutaneous blood flow contributes to the decrease in SV f Cardiac drift is greater if the subject is dehydrated or exercising in a hot/humid environment g all of the above ARE true h three of the above

The volume of blood in the ventricle would be decreasing:

a when ventricular pressure is higher than the aortic pressure b when the aortic valve is open c after the second heart sound d all of the above e a & b f b & c

Internal respiration

cellular respiration

After aerobic exercise sustained vasodilation in the active muscle may be due to secretion of _____ from Mast Cells; this may contribute to post exercise hypotension

histamine

visceral pleura

inner layer of pleura lying closer to the lung tissue

Myoglobin

is found in red blood cells b has a lower affinity for oxygen than hemoglobin c even at a somewhat low tissue pO2 of 40mmHg, myoglobin would be more saturated than hemoglobin d two of the above e none of the above

parietal pleura

outer layer of pleura lying closer to the ribs and chest wall

On an EKG, the T wave represents the _

repolarization of ventricles