In which of the following conditions will erythrocyte concentration of 2,3-DPG be decreased?

Anemia

Banked Blood

High ph

Hypoxemia

Banked Blood

An area of the lung has no ventilation but is normally perfused by the pulmonary circulation. Which of the following statements are correct?

a)Blood exiting the pulmonary capillary will have a PO2= 40 and a PCO2=46

b)The area represents an alveolar shunt

c)The V/Q is 0

a,b, and c

At body temparature, how much oxygen will physically dissolve in plasma at a PO2 of 40 mm Hg?

a) 0.12 ml/dl

b) 0.20 ml/dl

c) 0.30 ml/dl

d) 1.34 g/dl

a) 0.12 ml/dl

When is the rate of gaseous diffusion across a biological membrane decreased?

a) The diffusion distance is small

b) The gas diffusion constant increases

c) The partial pressure gradient is low

d) the surface area is large

c) The partial pressure gradient is low

When Hb saturation with oxygen is high, less carbon dioxide is carred in the blood. What is the relationship called?

a) Bohr effect

b) Chloride shift

c) Dissociation constant

d) Haldane effect

d) Haldane effect

The lowest PO2 would normally be found in what location?

a) arterial blood

b) atomospheric air

c) cells

d) venous blood

c) cells

What role does the Bohr effect play in oxygen transport?

a) describes the affect of varing enzyme levels on Hb and oxygen affinity

b) diminishes tissue oxygenation due to electrocyte imbalances

c) enhances oxygen dilivery to tissues and oxygen pickup at lungs

c) ehances oxygen dilivery to tissues and oxygen pickup at the lungs

What is the most important component in the oxygen transport system?

a) dissolved oxygen in ml/dl

b) HCO3-

c) Hb

d) PaO2

c) Hb

Compared to normal levels, a shift in the HbO2 curve to the right has which of the following effects?

a) the affinity of Hb for oxygen decreases

b) the Hb saturation for a given PO2 falls

c) the Hb saturation for a given PO2 rises

a) the affinity of Hb for oxygen decreases and b) the Hb saturation for a given PO2 falls

Why is the presence of carbonic anhydrase in RBCs so crucial for carbon dioxide transport?

a) forms H2CO3 which is the major buffer for carbon dioxide

b) drives the hydrolysis reaction that forms HCO3-

c) forms H2CO3, which is the way the majority of the carbon dioxide is transported

b) drives the hydrolysis reaction that forms HCO3-

Which of the following would you expect to find with "oxygen debt"?

a) accentuated in diseases such as sepsis

b) oxygen demand exceeds oxygen delivery

c) oxygen excess usage results in debt

a) accentuated in diseases such as sepsis and b) oxygen demand exceeds oxygen delivery

A patient has a P50 value of 29 mm Hg. What does this indicate?

a) decreased affinity of Hb for oxygen

b) higher than normal Hb saturation for a given PO2

c) increased affinity of Hb for oxygen

d) normal position in the HbO2

a) decreased affinity of Hb for oxygen

Which of the following values corresponds most closely to the normal PO2 and PCO2 in the mixed venous blood returning to the lungs from the right side of the heart?

a) PO2 = 40 mm Hg; PCO2 = 46 mm Hg

b) PO2 = 40 mm Hg; PCO2 =100 mm Hg

c) PO2 = 100 mmHg; PCO2 = 40 mm Hg

d) PO2 = 100 mmHg; PCO2 = 46 mm Hg

a) PO2 = 40 mm Hg; PCO2 = 46 mm Hg

Which of the following are true regarding fetal hemoglobin?

a) it has a reduced level of 2,3-DPG

b) it is replaced in the first month of life

c) it delivers more oxygen to tissues at low PaO2 than normal Hb

d) it has a higher P50 than normal Hb

c) it delivers more oxygen to tissues at low PaO2 than normal Hb

Which of the following are true regarding the PACO2?

a) directly proportional to whole-body carbon dioxide production

b) inversely proportional to alveolar ventilation (VA)

c) normally maintained at about 35 to 45 mm Hg

a) directly proportional to whole-body carbon dioxide production b) inversely proportional to alveolar ventilation (VA) and c) normally maintained at about 35 to 45 mm Hb

The largest percentage of carbon dioxide transported in the blood occurs as which of the following?

a) carbamino-Hb

b) carbonic acid (H2CO3)

c) HCO3-

d) physically dissolved carbon dioxide

c) HCO3-

What is the approximate normal level of carbon dioxide production (CO2) for an adult?

a) 200 ml/min

b) 250 ml/min

c) 4200 ml/min

d) 6000 ml/min

a) 200 ml/min

Regarding pulmonary blood flow in the upright lung, which of the following statements is true?

a) the apexes receive about 20 times more blood flow than the bases

b) the bases receive about 20 times more blood flow than the apexes

c) the greatest blood flow is found at the apexes of the lungs

d) the pulmonary circulation is a high-pressure system

b) the bases receive about 20 times more blood flow than the apexes

Given the following blood parameters, compute the total oxygen content (dissolved + HbO2) of the blood in ml/dl: Hb=16; PO2=625 Hg; SO2=100%

a) 17.8 ml/dl

b) 19.4 ml/dl

c) 21.4 ml/dl

d) 23.3 ml/dl

F: CaO2 = (0.003 x PO2) + (Hb x 1.34 x So2)

d) 23.3 ml/dl

In which of the following forms is carbon dioxide transported by the blood?

a) chemically combined with proteins

b) ionized as bicarbonate (HCO3-)

c) simple physical solution

a) chemically combined with proteins, b) ionized as bicarbonate (HCO3-), and c) simple physical solution

Even in healthy young subjects, regional differences in pulmonary ventilation and blood flow result in the PaO2 being lower that the PAO2. Why is this so?

a) most blood flows through the apexes of the lung

b) most blood flows through areas with high V/Q

c) most blood flows through the bases of the lung

d) most ventilation goes to the apexes of the lung

c) most blood flows through the bases of the lung

Under what conditions will the alveolar PACO2 rise above normal?

a) if both metabolic rate and ventilation increase (e.g., through exercise)

b) if carbon dioxide production decreases relative to VA

c) if VA decreases relative to carbon dioxide production

d) when the patient is febrile

c) if VA decreases relative to carbon dioxide

On what does the movement of gases between the lungs and the body tissues mainly depend?

a) active transport

b) gaseous diffusion

c) membrane dialysis

d) membrane transport

b) gaseous diffusion

The expected PaO2 for an 80-year-old man who is otherwise in good health and breathing room air is about what level?

a) 50 mm Hg

b) 75 mm Hg

c) 80 mm Hg

d) 90 mm Hg

F: PaO2 = 100.1- (0.323 x age)

b) 75 mm Hg

Which of the following equations best discribes oxygen delivery to the tissues?

a) arterial oxygen content / cardiac output

b) arterial oxygen content x cardiac output

c) cardiac output + arterial oxygen content

d) cardiac output x vascular resistance

Formula: DO2 = CaO2 x Qt

b) arterial oxygen content x cardiac output

A patient has a whole-body oxygen consumption of 320 ml/min and a measured CaO2 - Cv o2 of 8 ml/dl. What is the cardiac output?

a) 3.2 L/min

b) 4.0 L/min

c) 5.0 L/min

d) 7.0 L/min

b) 4.0 L/min

Given the following blood parameters, compute the total oxygen content (dissolved + HbO2) of the blood in ml/dl: Hb = 18; PO2 = 40 mm Hg; SO2 = 73%

a) 16.5 ml/dl

b) 17.7 ml/dl

c) 18.6 ml/dl

d) 19.5 ml/dl

F: CaO2 = (0.003 x PO2) + (Hb x 1.34 x SO2)

b) 17.7 ml/dl

Hypoxia is best defined as a condition in which. What occurs?

a) blood Hb levels are less than normal (15 g/dl)

b) the arterial PCO2 is greater than normal (45 mm Hg)

c) the arterial PO2 is greater than normal (100 mm Hg)

d) tissue oxygen delivery is inadequate to meet celluar needs

d) tissue oxygen delivery is inadequate to meet cellular needs

What is the normal range of PAO2 - PaO2 for healthy young adults breathing room air?

a) 5 to 10 mm Hg

b) 10 to 20 mm Hg

c) 20 to 30 mm Hg

d) 50 to 60 mm Hg

a) 5 to 10 mm Hg

What is the most common cause of hypoxemia?

a) diffusion defect

b) hypoventilation

c) right-to-left shunt

d) V/Q mismatch

d) V/Q mismatch

According to the Bohr effect, when the ph drops (blood becomes more acidic). What happens?

a) the affinity of Hb for oxygen decreases

b) the Hb saturation for a given PO2 falls

c) the Hb saturation for a given PO2 rises

a) the affinity of Hb for oxygen decreases, and b) the Hb saturation for a given PO2 falls

Carbon dioxide diffuses across the alveolar-capillary membrane about how many times faster than oxygen?

a) 10

b) 20

c) 30

d) 40

b) 20

Which of the following "layers" must be traversed by gases moving across the alveolar-capillary membrane?

a) alveolar epithelial membrane

b) capillary endothelial membrane

c) interstitial space

d) transbronchial radial tethering mechanisms

a) alveolar epithelial membrane, b) capillary endothelial membrane, and c) interstitial space

Which of the following does Not increase the affinity of Hb for oxygen?

a) decreased 2,3-DPG

b) decreased PCO2

c) increased ph

d) increased temperature

d) increased temperature

The time available for diffusion in the lung is mainly a function of which of the following?

a) functional residual capacity (FRC)

b) inspired oxygen concentration

c) level of VA

d) rate of pulmonary blood flow

d) rate of pulmonary blood flow

Under normal physiologic circumstances, how many milliliters of oxygen are capable of combining with 1g of Hb?

a) 0.003 ml

b) 0.450 ml

c) 0.820 ml

d) 1.340 ml

d) 1.340 ml

What is the primary determinant of the PAO2?

a) body's VCO2

b) metabolic rate of the body tissues

c) PaO2

d) PO2 in the inspired gas

d) PO2 in the inspired gas

Which of the following statements is true regarding the Haldane effect?

a) at high SaO2 levels carbon dioxide more readily forms carbamino compounds

b) at high SaO2 levels the capacity of blood hold to carbon dioxide decreases

c) at high SaO2 levels the capacity of blood hold to carbon dioxide increases

d) at low SaO2 levels the capacity of blood hold to carbon dioxide decreases

b) at high SaO2 levels the capacity of blood hold to carbon dioxide decreases

What is the highest PAO2 a RT could expect to observe in an individual breathing room air at sea level?

a) 90 to 100 mm Hg

b) 110 to 120 mm Hg

c) 640 to 670 mm Hg

d) 710 to 760 mm Hg

b) 110 to 120 mm Hg

How is the vast majority of oxygen carried in the blood?

a) as a bicarbonate ion (HCO3)

b) as carbamino compounds

c) chemically combined with Hb

d) in a physical solution

c) chemically combined with Hb

An abnormal metabolic state in which the tissues are unable to utilize the oxygen made available to them best describes which of the following:

a) diffusion hypoxia

b) dysoxia

c) hemic hypoxia

d) physiologic shunt

b) dysoxia

What is the affect of an elevated intracellular 2,3-DPG concentration?

a) decreases the availability of oxygen to the tissues

b) increases the affinity of Hb for oxygen

c) increases the availability of oxygen to the tissues

d) shifts the HbO2 dissociation curve to the left

c) increases the availability of oxygen to the tissues

What happens when the temparature of the blood rises?

a) the Hb saturation for a given PO2 falls

b) the HbO2 curve shifts to the right

c) the affinity of Hb for oxygen increases

a) the Hb saturation for a given PO2 falls, and b) the HbO2 curve shifts to the right

As the amount of oxygen that dissolves in the plasma increases, what is it directly proportionate to?

a) its partial pressure

b) its solubility coefficient

c) minute ventilation

d) temparature

a) its partial pressure

Why is it necessary to keep the patient's PaO2 greater than 60 mm Hg?

a) a level of 60 mm Hg marks the beginning of the steep part of O2Hb dissociation curve

b) below the 60 mmHg level, hypoxia is ensured

c) oxygen deprivation will cause severe cerebral vasoconstriction below 60 mm Hg

d) the PaCO2 will start to rise precipitously if the PaO2 falls further

a) a level of 60 mm Hg marks the beginning of the steep part of the O2Hb dissociation curve

Which of the following gases would diffuse fastest across the alveolar-capillary membrane?

a) air

b) carbon dioxide

c) oxygen

d) nitrogen

b) carbon dioxide

If the total hemoglobin content (Hb+HbO2) of a sample is 20 g/dl and the oxyhemoglobin (HbO2) content is 15 g/dl, what is the HbO2 saturation?

a) 17%

b) 50%

c) 75%

d) 83%

Hint use the hemoglobin saturation formula: SaO2 = (HbO2/total Hb) x 100

a) 75%

Which of the following are potential causes of hypoxia?

a) decrease in arterial PO2

b) decrease in available Hb

c) decrease in cardiac output

a) decrease in arterial PO2, b) decrease in available Hb, and c) decrease in cardiac output

The highest PCO2 levels are found in what location?

a) arterial blood

b) atmospheric air

c) cells

d) venous blood

c) cells

In a person breathing room air (and with all else being normal), if the alveolar PCO2 rises from 40 to 70 mm Hg, what would the RT expect to see?

a) PAO2 to fall by about 30 mm Hg

b) PAO2 to fall by about 40 mm Hg

c) PAO2 to rise by about 30 mm Hg

d) PAO2 to rise by about 40 mm Hg

a) PAO2 to fall by about 30 mm Hg