Physiology Exam 2

Normal, resting tidal volume is about A) 0.5 liters per inhalation B) 0.5 liters for inhalation and exhalation combined C) 2 liters for inhalation D) 2 liters for inhalation and exhalation combined

A) 0.5 liters per inhalation

In a young, healthy adult at rest, atrial contraction contributes approximately ________ to ventricular volume at the end of diastole. A) 15% B) 45% C) 65% D) 85%

A) 15%

Consistent P-R intervals of 240 milliseconds is indicative of A) 1st degree heart block B) 2nd degree heart block C) 3rd degree heart block D) Junctional rhythm

A) 1st degree heart block EKG lecture slide 4. Intervals are consistent, just >200 ms

The only electrical connection between the atria and the ventricles in a normal heart is through the _______. A) AV node B) SA node C) Bundle branches D) Purkinje fibers

A) AV node

Which of the following is produced in response to a hemorrhage and causes an increase in renal Na+ reabsorption? A) Aldosterone B) Angiotensin I C) Angiotensinogen D) Antidiuretic hormone

A) Aldosterone

All the following can change diameter by constricting/dilating except _______. A) Capillaries B) Arterioles C) Arteries D) Veins

A) Capillaries

Capillaries in most tissues of the body leak fluid at their start but reclaim it by their end. The fluid that does not get drawn back into the capillaries is A) Carried back to the vasculature through lymphatic vessels B) Expelled from the skin as sweat and perspiration C) Converted to protons and CO2 by the cells in those tissues D) Used by mitochondria to produce ATP

A) Carried back to the vasculature through lymphatic vessels

During auscultation of the heart (listening with a stethoscope over the chest), the first heart sound occurs upon the A) Closing of atrioventricular valves B) Opening of atrioventricular valves C) Opening of aortic and pulmonary semilunar valves D) Closing of aortic and pulmonary semilunar valves

A) Closing of atrioventricular valves

In the transport of CO2 from the tissues to the lungs, which of the following occurs in venous blood? A) Conversion of CO2 and H2O to H+ and HCO3- in the red blood cells (RBCs) B) Buffering of H+ by carboxyhemoglobin C) Shifting of HCO3− into the RBCs from plasma in exchange for Cl− D) Binding of HCO3− to hemoglobin

A) Conversion of CO2 and H2O to H+ and HCO3- in the red blood cells (RBCs)

A 34-year-old man has just gotten over food poisoning with vomiting and diarrhea for several days. Though he's no longer symptomatic, he continues to feel light-headed if he stands up too quickly. Which of the following explains his symptoms? A) Decreased blood volume, decreased preload, decreased cardiac output B) Increased heart rate, increased cardiac output C) Increased sympathetic output, increased total peripheral resistance, increased arterial pressure D) Increased renin levels, increased angiotensin II levels, increased aldosterone level

A) Decreased blood volume, decreased preload, decreased cardiac output

During diastole, blood continues to flow and blood pressure does not drop to zero because the larger arteries are ______. A) Elastic and return stored energy during diastole B) Covered in smooth muscle that contracts during diastole C) Elastic and return stored energy during systole D) Covered in smooth muscle that contracts during systole

A) Elastic and return stored energy during diastole "Diastolic blood pressure (DP) is the lowest pressure in an artery at the beginning of the cardiac cycle while the ventricles are relaxing and filling. DP is directly proportional to total peripheral resistance (TPR). Also, the energy stored in the compliant aorta during systole is now released by the recoil of the aortic wall during diastole, thus increasing diastolic pressure."

The low-resistance pathways between myocardial cells that allow for the spread of action potentials are the A) Gap junctions B) T tubules C) Sarcoplasmic reticulums (SR) D) Intercalated disks

A) Gap junctions

An 84-year-old man at sea level has the following arterial blood gas values: PaO2 60 mmHg, PaCO2 70 mmHg. Which of the following would produce these results? A) Hypoventilation B) Fibrosis C) V̇/Q̇ defect D) Anemia

A) Hypoventilation

Which of the following is true during inspiration? A) Intrapleural pressure is more negative than it is during expiration B) The volume in the lungs is less than the functional residual capacity (FRC) C) Alveolar pressure equals atmospheric pressure D) Alveolar pressure is higher than atmospheric pressure

A) Intrapleural pressure is more negative than it is during expiration

Electrical current passing from the SA node to the AV node creates the ______ wave of an ECG tracing. A) P B) Q C) S D) T

A) P atria depolarization aka current passing from SA to AV node

People can experience side-effects of traveling to higher altitude, such as headaches, because the A) Partial pressure of oxygen is lower at altitude B) Percentage of oxygen in air is lower at altitude C) Percentage of carbon dioxide in air is higher at altitude D) Percentage of carbon dioxide in air is lower at altitude

A) Partial pressure of oxygen is lower at altitude

Which person would be expected to have the largest A-a (alveolar to arterial) gradient? A) Person with pulmonary fibrosis B) Person who is hypoventilating due to morphine overdose C) Person at 12,000 ft above sea level D) Person with normal lungs breathing 100% O2

A) Person with pulmonary fibrosis -thicker walls, increased diffusion distance for O2 → hypoxemia (greater difference between alveolar gas and arterial blood PO2) -Increased A-a = lack of O2 equilibration between alveolar gas and arterial blood -in other options, the blood and alveolar PO2 would equilibrate

Orthostatic (or postural) hypotension is a failure in the ability to ______________ when we stand up. A) Reduce compliance of blood vessels in the lower body B) Increase compliance of blood vessels in the lower body C) Reduce compliance of blood vessels in the upper body D) Increase compliance of blood vessels in the upper body

A) Reduce compliance of blood vessels in the lower body

Cerebrospinal fluid is more acidic during respiratory acidosis than during metabolic acidosis. A) True B) False

A) True CO2 can cross the BBB during respiratory acidosis and dissociate, creating protons, lowering the pH, and during metabolic acidosis, the acids created can't cross the BBB

Most of the blood volume resides in the A) Veins B) Arteries C) Pulmonary circulation D) Capillaries

A) Veins

An outcome of blood doping with erythropoietin that is of clinical concern is A) increased blood viscosity B) reduced total peripheral resistance (TPR) C) reduced stroke volume D) increased venous compliance

A) increased blood viscosity

A teenage athlete is both growing taller and developing the endurance capacity of their muscles. Longer arteries that come with growing taller ________ there resistance to blood flow and an increase in the number of capillaries in skeletal muscles, which occurs with exercise training, ______ the resistance to blood flow through the those muscles. A) increases, decreases B) decrease , decreases C) decreases , increases D) increases, increases

A) increases, decreases We lose compliance quickly as we shift to long arteries. More capillaries=decreasing parallel resistance

In a healthy individual, lung ventilation is ______ sensitive to PaCO2 than PaO2, especially at _____ PaO2. A) more, high B) less, high C) more, low D) less, low

A) more, high

Surfactant is produced by cells in the _______ airways to _______ the tendency of those airways to collapse (atelectasis). A) respiratory, reduce B) conducting, enhance C) respiratory, enhance D) conducting, reduce

A) respiratory, reduce Produced by alveolar cells

Anastomoses at the circle of Willis and among the branches of distributing arteries protect the blood supply to the brain, which is _______% of resting cardiac output. A) 5 B) 15 C) 25 D) 35

B) 15

For an average adult, at the end of ventricular systole (a heart beat/contraction) the volume of blood remaining in the ventricles is about ________ of what it started the beat with (when it was full). A) 20% B) 40% C) 60% D) 80%

B) 40%

While seated or standing, compared with the apex of the lung, the base of the lung has A) A higher pulmonary capillary PO2 B) A higher pulmonary capillary PCO2 C) A higher ventilation/perfusion (V/Q) ratio D) The same V̇/Q̇ ratio

B) A higher pulmonary capillary PCO2

In the sinoatrial (SA) node, phase 4 depolarization (pacemaker potential) is primarily attributable to A) An increase in K+ conductance B) An increase in Na+ conductance C) A decrease in Ca2+ conductance D) Simultaneous increases in K+ and Cl− conductance

B) An increase in Na+ conductance Funny currents cause the pacemaker potential, slow rising current, which is a Na/K channel

Which type of blood vessel controls where cardiac output goes in the body by controlling resistance through constriction and dilation? They are sometimes called 'resistance vessels'. A) Arteries B) Arterioles C) Capillaries D) Veins

B) Arterioles Biggest pressure change here

A person's electrocardiogram (ECG) has no P wave but has normal QRS complexes and normal T waves. Therefore, his pacemaker is in the A) Sinoatrial (SA) node B) Atrioventricular (AV) node C) Bundle of His D) Ventricular muscle

B) Atrioventricular (AV) node

Nearly 70% of incremental CO2 (the CO2 produced by tissue cells as blood passes through capillaries) is carried as _____. A) Carbaminohemoglobin B) Bicarbonate C) Dissolved gas D) Carbonic acid

B) Bicarbonate Ch. 5 slide 19

Hypoxemia produces hyperventilation by a direct effect on the A) Phrenic nerve B) Carotid and aortic chemoreceptors C) Lung stretch receptors D) Medullary chemoreceptors

B) Carotid and aortic chemoreceptors Peripheral chemoreceptors are sensitive to oxygen, whereas central are sensitive to proton concentration.

Lowering heart rate from 175 to 160 is accomplished mainly by A) Increasing parasympathetic activity B) Decreasing sympathetic activity C) Decreasing parasympathetic activity D) Increasing sympathetic activity

B) Decreasing sympathetic activity "at high HR we get more/less Norepi to change HR"

If an area of the lung is not ventilated because of bronchial obstruction, the pulmonary capillary blood serving that area will have a PO2 that is A) Equal to atmospheric PO2 B) Equal to mixed venous PO2 C) Higher than inspired PO2 D) Lower than mixed venous PO2

B) Equal to mixed venous PO2 -No ventilation = no gas exchange = no equilibration of blood and alveolar PO2 (PO2 will be equal to mixed venous blood returning) -On figure 5.31, shows PaCO2 in an airway obstruction is 46, which is the same as mixed venous blood in the chart at the end of the powerpoint

Pulse pressure is highest in which of the following? A) Aorta B) Femoral artery C) Arterioles D) Veins

B) Femoral artery PP biggest in large arteries

The physiologic function of the relatively slow conduction through the atrioventricular (AV) node is to allow sufficient time for A) Venous return to the atria B) Filling of the ventricles C) Contraction of the ventricles D) Repolarization of the ventricles

B) Filling of the ventricles We want the atria to fully contract before ventricle

Just after death, the volume of air in a person's lungs is A) Residual volume B) Functional residual volume C) Tidal volume D) Vital capacity

B) Functional residual volume

If you hold your breath for a while, you'll feel a strong urge to breathe. The urge is due to _______ levels in the blood. A) Low oxygen B) High carbon dioxide C) High oxygen D) Low carbon dioxide

B) High carbon dioxide

The tendency for edema to occur will be increased by A) Arteriolar constriction B) Increased venous pressure C) Increased plasma albumin concentration D) Rhythmic skeletal muscle contraction during exercise

B) Increased venous pressure Pulmonary HTN causes edema

During exercise, the relative volumes of cardiac output to different organs is redistributed compared to resting distributions. Which of the following gets less blood flow during exercise than it did at rest. A) Brain B) Kidneys C) Lungs D) Heart

B) Kidneys Brain stays constant, lungs and heart would increase

Which of the following is the site of highest airway resistance? A) Trachea B) Large bronchi C) Bronchioles E) Alveoli

B) Large bronchi -Due to the vast number of bronchioles that are present within the lungs running in parallel, the highest total resistance is actually in the trachea and larger bronchi

Dany is an endurance athlete who has come in for a routine sports physical examination. Their ECG shows an R peak that is positive in lead 1, negative in aVF, and negative in lead 2. You conclude they have A) Normal cardiac electrical axis (no deviation) B) Left axis deviation C) Right axis deviation D) Extreme right axis deviation

B) Left axis deviation EKG lecture slide 4

Compared with the systemic circulation, the pulmonary circulation has a A) Higher blood flow B) Lower resistance C) Higher arterial pressure D) Higher capillary pressure

B) Lower resistance

Systolic pressure in the pulmonary arteries is about ________ what it is in the aorta. A) The same as B) One-fifth of C) Half of D) Twice

B) One-fifth of Aorta MAP 100, pulmonary artery 15

Which volume remains in the lungs after a maximal expiration? A) Vital capacity (VC) B) Residual volume (RV) C) Functional residual capacity (FRC) D) Inspiratory capacity (IC)

B) Residual volume (RV)

Pulse pressure is A) The highest pressure measured in the arteries B) The difference between systolic and diastolic pressures C) Decreased when the capacitance of the arteries decreases D) The difference between mean arterial pressure and central venous pressure

B) The difference between systolic and diastolic pressures

Which of the following is NOT the result of an inward calcium current? A) Upstroke of the action potential in the sinoatrial (SA) node B) Upstroke of the action potential in atrial muscle C) Plateau of the action potential in ventricular muscle D) Cardiomyocyte contraction

B) Upstroke of the action potential in atrial muscle

Cardiac output of the right side of the heart is what percentage of the cardiac output of the left side of the heart? A) 40% B) 80% C) 100% D) 120%

C) 100%

Regular and consistent P-waves at a rate of 80 per minute with non-corresponding QRS waves at a regular rate of 70 per minute (P and QRS are never matched) is indicative of A) 1st degree heart block B) 2nd degree heart block C) 3rd degree heart block D) Junctional rhythm

C) 3rd degree heart block "no relation between P and QRS"

Which of the following agents has a negative inotropic effect on the heart? A) Sympathetic stimulation B) Norepinephrine C) Acetylcholine D) Cardiac glycosides

C) Acetylcholine Negative inotropic effect will decrease contractility, lower SC, CO, EF PNS decreases contractility through decreasing Ca and increasing K/Ach

An increase in arteriolar resistance, without a change in any other component of the cardiovascular system, will produce A) A decrease in total peripheral resistance (TPR) B) An increase in capillary filtration C) An increase in arterial pressure D) A decrease in afterload

C) An increase in arterial pressure

The degree of myocardial contractility is closely correlated with the intracellular concentration of A) Na+ B) K+ C) Ca2+ D) Mg2+

C) Ca2+ Increase intracellular Ca2+ increases inotropism (myocardial contractility)

The heart cannot be stimulated to contract again while it is in the middle of a contraction because _________ channels stay open and keep membrane potential near zero, preventing repolarization long enough for the heart muscle to fully contract. A) Sodium B) Potassium C) Calcium D) Chloride

C) Calcium Slide 12 of Ch. 4 powerpoint

Cross-sectional area is highest and velocity is lowest in the A) Arteries B) Arterioles C) Capillaries D) Veins

C) Capillaries

Raising heart rate to its resting daytime value when you wake up from sleep is mostly accomplished by ________ . A) Increasing parasympathetic activity B) Decreasing sympathetic activity C) Decreasing parasympathetic activity D) Increasing sympathetic activity

C) Decreasing parasympathetic activity "at low HR, we do more/less Act until we reach the normal point"

Which of the following is true? A) Fibrotic lungs have low compliance and are easy to inflate B) Fibrotic lungs have high compliance and are easy to inflate C) Emphysematous lungs have high compliance and are easy to inflate D) Emphysematous lungs have high compliance and are difficult to inflate

C) Emphysematous lungs have high compliance and are easy to inflate

Fetal hemoglobin _____. A) Binds oxygen less avidly than adult hemoglobin B) Is highly sensitive to 2,3 DBG levels C) Has a higher hemoglobin saturation for any PO2 D) Is made from four beta-chains (doesn't have alpha chains)

C) Has a higher hemoglobin saturation for any PO2 Ch. 5 lecture slide 16

When a person is standing, blood flow in the lungs is A) Equal at the apex and the base B) Highest at the apex owing to the effects of gravity on arterial pressure C) Highest at the base because that is where the difference between arterial and venous pressure is greatest D) Lowest at the base because that is where alveolar pressure is greater than arterial pressure

C) Highest at the base because that is where the difference between arterial and venous pressure is greatest

Which of the following changes will cause an increase in myocardial O2 consumption? A) Decreased heart rate B) Decreased contractility C) Increased size of the heart D) Increased influx of Na+ during the upstroke of the action potential

C) Increased size of the heart

A 6-year-old girl is feeling very ill. She is disoriented, has a high fever of 40.5C (~105 F), and is experiencing muscle cramping. She hasn't eaten in 36 hours and is having trouble staying hydrated due to vomiting upon drinking. Her breathing is mildly tachypnic and she has a PaO2 of 100 mmHg, PaCO2 of 36 mmHg, Hb saturation of 91%. What is the most likely cause of her lower-than-normal hemoglobin saturation? A) Acidosis B) Dehydration C) Increased temperature D) Carbon monoxide (CO) poisoning

C) Increased temperature Ch. 5 slide 16

During exercise, total peripheral resistance (TPR) decreases because of the effect of A) The sympathetic nervous system on splanchnic arterioles B) The parasympathetic nervous system on skeletal muscle arterioles C) Local metabolites on skeletal muscle arterioles D) Local metabolites on cerebral arterioles

C) Local metabolites on skeletal muscle arterioles

A 52-year-old woman presents with the complaint of chronic dyspnea over the past month. Her spirometry results show tidal volume 500 ml, FEV1 1.5 L, FVC 3 L. These results are consistent with which of the following? A) Both restrictive and obstructive lung disease (i.e., inconclusive) B) Restrictive lung disease only C) Obstructive lung disease only D) Neither restrictive nor obstructive lung disease - these are normal values and her dyspnea must have another cause

C) Obstructive lung disease only

The tendency for blood flow to be turbulent is increased by A) Increased viscosity B) Increased hematocrit C) Partial occlusion of a blood vessel D) Decreased velocity of blood flow

C) Partial occlusion of a blood vessel

Electrical current depolarizing the upper/base of the ventricular muscle creates the ______ wave of an ECG tracing. A) P B) Q C) S D) T

C) S Base is the top of the ventricle, this is the last part to depolarize

The ventricles are completely depolarized during which isoelectric portion of the electrocardiogram (ECG)? A) PR segment B) QRS wave C) ST segment D) T wave

C) ST segment

A normal, healthy adult moves from San Diego, California (sea level) to Leadville, Colorado (10,200 ft above sea level). Which of the following do you expect to happen? A) Hypoventilation B) Arterial PO2 >100 mm Hg C) Shift to the right of the hemoglobin-O2 dissociation curve D) Respiratory acidosis

C) Shift to the right of the hemoglobin-O2 dissociation curve

Large preload (higher end-diastolic volume) keeping all else equal, causes a A) Stronger contraction and smaller stroke volume. B) Weaker contraction and smaller stroke volume. C) Stronger contraction and larger stroke volume D) Weaker contraction and larger stroke volume.

C) Stronger contraction and larger stroke volume Ch. 4 slide 19, also frank-starling law

A 46-year-old woman with severe pulmonary fibrosis is evaluated by her PA and has these arterial blood values: pH = 7.5, PaO2 = 56 mm Hg, and PaCO2 = 34 mm Hg. Which statement best explains her PaO2 value? A) The increased pH stimulates breathing via peripheral chemoreceptors B) The increased pH stimulates breathing via central chemoreceptors C) The decreased PaO2 stimulates breathing via peripheral chemoreceptors D) The decreased PaO2 stimulates breathing via central chemoreceptors

C) The decreased PaO2 stimulates breathing via peripheral chemoreceptors -PaO2 56 mm Hg (~88%); peripheral = O2, CO2, H+ & central = H+ in CSF (decreased pH)

Calcium channel blockers are often given for hypertension because they reduce TPR, and they can also_______ the work of the heart and _______ heart rate. A) reduce, increase B) increase, increase C) reduce, reduce D) increase, reduce

C) reduce, reduce

A 'narrow' QRS is typically anything less than _____ while a 'wide' QRS is anything more. A) 200 milliseconds B) 1 small box C) 3 small boxes D) 80 milliseconds

D) 80 milliseconds EKG lecture slide 2.

Imaging shows a 58-year-old woman to have 50% narrowing of her right carotid artery due to atherosclerosis. Blood flow through that artery will be decreased by about A) 50% B) 75% C) 88% D) 94%

D) 94%

A 62-year-old woman exhibits low blood-pressure when shifting from seated to standing. She had a sympathectomy several years ago. The explanation for this occurrence is A) An exaggerated response of the renin-angiotensin-aldosterone system B) A suppressed response of the renin-angiotensin-aldosterone system C) An exaggerated response of the baroreceptor reflex mechanism D) A suppressed response of the baroreceptor reflex mechanism

D) A suppressed response of the baroreceptor reflex mechanism

An otherwise healthy 32-year-old man suddenly becomes short of breath with reduced oxygen saturation upon even mild exertion. He is found on imaging to have pulmonary emboli through both lungs that block blood flow in many arteries. As a result, which of the following will occur in the affected regions? A) V̇/Q̇ ratio will be zero or near zero in those regions B) PO2 will be elevated in the blood leaving those regions C) Alveolar PO2 of those regions will be closer to the PO2 in venous blood D) Alveolar PO2 of those regions will be closer to the PO2 in inspired air

D) Alveolar PO2 of those regions will be closer to the PO2 in inspired air The V/Q ratio is infinity in a PE because our PAO2 is 150 (close to that of inspired air) but our PACO2 is 0 because we are not getting any perfusion, because we are not even able to bring blood back to this area and give it the CO2 made in our tissues (Pa of both O and CO2 is 0)

Resting heart rate is determined by __________ . A) Only parasympathetic nervous system activity B) Only sympathetic nervous system activity C) Only the intrinsic rate of the heart itself D) Balance among sympathetic, parasympathetic, and the intrinsic rate of the heart itself

D) Balance among sympathetic, parasympathetic, and the intrinsic rate of the heart itself "at rest we get release of both PNS (more) and SNS (less) on SA node"

In a capillary, Pc is 28 mm Hg, Pi is −1 mm Hg, πc is 23 mm Hg, and πi is 2 mm Hg. What is the direction of fluid movement and the net driving force? [note: if this question is on the exam, the numbers will be different] A) Absorption; 5 mm Hg B) Absorption; 8 mm Hg C) Filtration; 5 mm Hg D) Filtration; 8 mm Hg

D) Filtration; 8 mm Hg

A 10-year-old boy presents to the emergency department having an asthmatic attack with severe wheezing. His breathing shallow and rapid; he soon becomes cyanotic (blue hue to skin). Arterial blood measurements are: PO2 60 mm Hg and PCO2 30 mm Hg. Which of the following is most likely true? A) Forced expiratory volume1/forced vital capacity (FEV1/FVC) is increased B) Ventilation/perfusion (V̇/Q̇) ratio is increased in the affected areas of his lungs C) His arterial PCO2 is higher than normal because of inadequate gas exchange - no D) His arterial PCO2 is lower than normal because hypoxemia is causing him to hyperventilate

D) His arterial PCO2 is lower than normal because hypoxemia is causing him to hyperventilate CO2 is perfusion limited, normal PCO2 is 40mmHg

Which of the following enhances hemoglobin saturation? A) Increased temperature B) Increased PCO2 C) Increased 2,3-BPG D) Increased pH

D) Increased pH

A 76-year-old patient presents for a routine wellness exam and is discovered to be hypertensive. Further tests return abnormal results: an increase in plasma renin activity, plasma aldosterone level, and left renal vein renin level. His right renal vein renin level is decreased. Which of the following is consistent with these findings? A) Aldosterone-secreting tumor B) Adrenal adenoma secreting aldosterone and cortisol C) Pheochromocytoma D) Left renal artery stenosis E) Right renal artery stenosis

D) Left renal artery stenosis

A person with a V̇/Q̇ defect has hypoxemia and is treated with supplemental oxygen. The supplemental oxygen will be most helpful if the person's predominant V̇/Q̇ defect is A) Dead space B) Shunt C) High V̇/Q̇ D) Low V̇/Q̇

D) Low V̇/Q̇ -Have highest blood flow (high PO2 will raise in a large volume of blood & have greatest influence on total blood flow leaving lungs)

The neurons that generate the respiratory rhythm are in the _____. A) Hypothalamus B) Cerebral cortex C) Pons D) Medulla oblongata

D) Medulla oblongata DRG in the medulla

Electrical current running perpendicular to the direction of and ECG lead will register as ______ on the tracing. A) A positive deflection B) A negative deflection C) A biphasic wave (first one direction then the opposite, like the RS section of the QRS complex) D) No change

D) No change

For someone with emphysema, pursed lips breathing _______. A) Reduces the likelihood of expansion in upper airways during inspiration B) Increases the likelihood of collapse in upper airways during inspiration C) Reduces the likelihood of alveolar collapse during expiration D) Reduces the likelihood of collapse of upper airways during expiration

D) Reduces the likelihood of collapse of upper airways during expiration The upper airway is the thing that is collapsing, and pursed lip breathing would cause resistance, would not decrease to 0 until the lips, so the upper airway would not collapse

Despite the addition of the body's metabolic products, venous blood has a pH that is only slightly more acidic than arterial blood because A) CO2 is a weak base B) There is no carbonic anhydrase in venous blood C) The H+ generated from CO2 and H2O is buffered by HCO3− in venous blood D) The H+ generated from CO2 and H2O is buffered by deoxyhemoglobin in venous blood

D) The H+ generated from CO2 and H2O is buffered by deoxyhemoglobin in venous blood H2CO3 → H+ (binds to Hb) + HCO3- (goes into plasma)

The greatest pressure decrease in the circulation occurs across the arterioles because A) They have the greatest surface area B) They have the greatest cross-sectional area C) The velocity of blood flow through them is the lowest D) They have the greatest resistance

D) They have the greatest resistance Arterioles are our resistance vessels

Which of the following parameters is decreased during moderate exercise? A) Arteriovenous O2 difference B) Heart rate C) Cardiac output D) Total peripheral resistance (TPR)

D) Total peripheral resistance (TPR)

Which of the following can be measured with spirometry? A) Physiologic dead space B) Residual volume C) Total lung capacity D) Vital capacity

D) Vital capacity Ch. 5 slide 2

Respiratory compensation for metabolic acidosis _______ blood H+ concentration and involves _______. A) increases; hyperventilation B) decreases; hypoventilation C) increases; hypoventilation D) decreases; hyperventilation

D) decreases; hyperventilation -Metabolic acidosis increases blood H+ concentrations, so the compensation would decrease it. We are trying to get rid of CO2, so we would increase RR.

A patient's ECG trace shows two P waves before each QRS complex. This pattern means there is A) impaired depolarization rate rate of the pacemaker in the sinoatrial (SA) node B) impaired depolarization rate of the pacemaker in the atrioventricular (AV) node C) enhanced firing rate of the pacemaker in the SA node D) impaired conduction through the AV node

D) impaired conduction through the AV node

Exercise at very high altitude can result in _________ PaO2 due to ________ limitation. A) elevated; diffusion B) reduced; perfusion C) elevated; perfusion D) reduced; diffusion

D) reduced; diffusion His objectives in syllabus state: "At high altitude, hypoxemia results from the decreased PO2 of inspired air" Hypoxemia refers to decreased oxygen in blood and diffusion limited gas exchange occurs in the example of strenuous exercise