CH. 22 Respiratory System Part 2

According to the oxygen-hemoglobin dissociation curve, PO2 in the lungs of 100 mm Hg results in Hb being 98% saturated. At high altitude, there is less O2. At a PO2 in the lungs of 80 mm Hg, Hb would be ________ saturated. A. 100% B. 95% C. 98% D. less than 50%

B. 95%

Which of the following types of drugs would NOT be appropriate for a patient with chronic asthma? A. An albuterol inhaler, which enhances sympathetic input to bronchioles. B. A cough suppressant, such as dextromethorphan. C. Epinephrine. D. Prednisone, which blunts the immune response.

B. A cough suppressant, such as dextromethorphan Your patient's primary problem is constriction of smooth muscle in the bronchioles. A cough suppressant would not address this problem.

Despite the fact that the partial pressure difference is so much smaller for CO2 , why is there as much CO2 exchanged between the alveoli and blood as there is O2 , ? A. The capillary walls are more permeable to CO2 than O2 . B. CO2 is much more soluble in blood than O2. C. CO2 is a smaller molecule and diffuses faster than O2 .

B. CO2 is much more soluble in blood than O2. Yes, because CO2CO2 is very soluble in blood, it does not require as large a pressure gradient as O2O2

Which of the following initiate(s) inspiration? A. ventral respiratory group (VRG) B. pontine respiratory centers C. midbrain D. dorsal respiratory group (DRG)

A. ventral respiratory group (VRG) The urge to breathe comes from the ventral respiratory group in the medulla oblongata. This urge is accelerated during hypoxia and can be suppressed by certain drugs.

As a result of hyperventilation, what will happen to the partial pressures of CO2 (pCO2) and pH? A. decreased pCO2 and increased pH. B. increased pCO2 and increased pH. C. increased pCO2 and decreased pH. D. decreased pCO2 and decreased pH

A.decreased pCO2 and increased pH Yes, pCO2 would decrease and pH would increase. As CO2 is blown off, H+ would decrease, thus increasing pH.

Steve may have emphysema, which is a type of obstructive lung disease. The alveoli are damaged and may collapse, which interferes with pulmonary ventilation. Choose the lung volumes and capacities that you would expect to be above normal in Steve's condition. A. VC B. FRC C. IC D. ERV E. IRV F. RV G.TV

B. FRC D. ERV F. RV Obstructive lung diseases are diseases that decrease a patient's ability to exhale air. The recoil of the lungs is decreased, which decreases the amount of air that can be exhaled and increases the amount of air remaining in the lungs. This would increase the RV, ERV and FRC.

Which way would O2 and CO2 diffuse during internal respiration? A. O2 would diffuse into the pulmonary capillaries and CO2 would diffuse into the alveoli. B. O2 would diffuse into the cells, and CO2 would diffuse into the systemic capillaries. C. O2 would diffuse into the systemic capillaries, and CO2 would diffuse into the cells. D. Both O2 and CO2 would diffuse into the systemic capillaries.

B. O2 would diffuse into the cells, and CO2 would diffuse into the systemic capillaries. Yes, the PO2 would be higher in the systemic capillaries, and the PCO2 would be higher in the tissues.

Select the correct statement about oxygen transport in blood. A. During normal activity, a molecule of hemoglobin returning to the lungs carries one molecule of O2. B. Increased BPG levels in the red blood cells enhance oxygen-carrying capacity. C. A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal. D. During conditions of acidosis, hemoglobin is able to carry oxygen more efficiently.

C. A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal.

What stimulates increased respiration at the beginning of exercise? A. increased hydrogen ion levels. B. increased plasma carbon dioxide levels. C. decreased plasma oxygen levels. D. sensory input from receptors in joints, neural input from the motor cortex, and other factors.

D. sensory input from receptors in joints, neural input from the motor cortex, and other factors Yes, at the beginning of exercise, blood gases have not changed; thus, other factors such as anticipation of exercise contribute to the increase in respiration.

Possible causes of hypoxia include ________. A. obstruction of the esophagus B. taking several rapid deep breaths C. getting very cold D. too little oxygen in the atmosphere

D. too little oxygen in the atmosphere

What area in the brain sets the respiratory rhythm? A. dorsal respiratory group (DRG) B. pontine respiratory group (PRG) C. hypothalamus D. ventral respiratory group (VRG)

D. ventral respiratory group (VRG) Yes, the VRG is the rhythm-generating center in the medulla.

Factors that influence the rate and depth of breathing include ________. A. stretch receptors in the alveoli. B. thalamic control C. temperature of alveolar air D. voluntary cortical control

D. voluntary cortical control

Your patient has been transported to the emergency department by EMS after a motor vehicle accident with an endotracheal tube in place. You note that his breath sounds are louder on the right side. You are alerted to which of the following situations? A. All of the listed responses are correct. B. Hemorrhage into the left pleural space (hemothorax) has compressed the left lung. C. The endotracheal tube has been inserted too far, with its tip in the right main bronchus, preventing the left lung from receiving air. D. Your patient may have a left pneumothorax.

A. All of the listed responses are correct. Pneumothorax, improper endotracheal tube placement, and blood in the pleural space (hemothorax) can all cause asymmetric breath sounds.

Which of the following best describes the chloride shift as seen in the figure? A. Chloride rushes into RBCs to counterbalance the outflow of bicarbonate. B. Chloride is taken out of the blood to counterbalance the inflow of carbon dioxide. C. Chloride binds to bicarbonate, which allows more of it to be carried in the bloodstream. D. Chloride is removed from hemoglobin when carbon dioxide binds to it.

A. Chloride rushes into RBCs to counterbalance the outflow of bicarbonate. The outflow of negative bicarbonate ions from RBCs is balanced by the inflow of chloride ions.

Which statement is correct? A. During external respiration, equilibrium is reached for O2 when the partial pressure for O2 in the pulmonary capillaries and the alveoli are the same. B. During external respiration, oxygen is unloaded from the blood. C. The greater the available surface area the lower the amount of gas exchange during internal respiration. D. During internal respiration, carbon dioxide is unloaded from the blood.

A. During external respiration, equilibrium is reached for O2 when the partial pressure for O2 in the pulmonary capillaries and the alveoli are the same. Yes, equilibrium is reached for O2O2 when the partial pressure of O2O2 in the pulmonary capillaries and the tissue cells are the same

Another category of lung disease is known as restrictive lung disease. Restrictive lung diseases can occur from the formation of scar tissue, which restricts the lung's ability to move. Choose all of the following lung volumes and capacities that you would expect to be decreased in an individual with restrictive lung disease. A. VC B. IC C. IRV D. RV E. TV F. FRC G.ERV

A. VC B. IC C. IRV D. RV E. TV F. FRC G.ERV Restrictive lung diseases are due to a decrease in the lungs' ability to inflate. This reduces the amount of air in the lungs and suppresses all lung volumes. Some examples of restrictive lung diseases are pulmonary sarcoidosis and fibrosis.

Steve is most likely using accessory muscles to help him breath. Choose which muscles Steve would be using. A. abdominals B. diaphragm C. scalenes D. internal intercostals E. external intercostals

A. abdominals D. internal intercostals The diaphragm is the prime mover of inspiration. If the diaphragm should become paralyzed, breathing will cease (apnea). Accessory muscles contract to change the shape of the thorax to increase volume differences, which allow more air to move into or out of the lungs. The scalene and external intercostal muscles are important for assisting with deeper inhalations. The internal intercostal and abdominal muscles are used for forced expirations.

How is the bulk of carbon dioxide transported in blood? A. as bicarbonate ions in plasma after first entering the red blood cells. B. chemically combined with the heme portion of hemoglobin. C. chemically combined with the amino acids of hemoglobin as carbaminohemoglobin in the red blood cells. D. as carbonic acid in the plasma

A. as bicarbonate ions in plasma after first entering the red blood cells.

Which of the following counteracts the movement of bicarbonate ions from the RBC? A. chloride shifting B. the Bohr effect C. the Haldane effect D. release of hydrogen ion

A. chloride shifting

The erythrocyte (red blood cell) count increases after a while when an individual goes from a low to a high altitude because the ________. A. concentration of oxygen and/or total atmospheric pressure is lower at high altitudes. B. temperature is lower at higher altitudes. C. concentration of oxygen and/or total atmospheric pressure is higher at higher altitudes. D. basal metabolic rate is higher at high altitudes.

A. concentration of oxygen and/or total atmospheric pressure is lower at high altitudes

Which form of CO2 transport accounts for the least amount of CO2 transported in blood? A. dissolved in plasma B. chemically bound to hemoglobin C. as carbon monoxide in plasma D. as bicarbonate ion in plasma

A. dissolved in plasma Most CO2 is transported in the blood bound to hemoglobin (forming carbaminohemoglobin) or in the form of bicarbonate ions. The latter occurs as CO2 entering the blood combines with water to form carbonic acid (H2CO3), which then dissociates into hydrogen ions and bicarbonate ions (HCO3− ). A very small percentage is dissolved into the plasma.

Which of the following is the leading cause of cancer death for both men and women in North America? A. lung B. colorectal C. esophageal D. skin

A. lung

Which of the following does NOT influence hemoglobin saturation? A. nitric oxide B. BPG C. temperature D. partial pressure of carbon dioxide

A. nitric oxide

Inspiratory neurons send information to the diaphragm via what nerve? A. phrenic nerve B. vegus nerve C. intercostal nerves D. glossopharyngeal nerve

A. phrenic nerve Yes, the phrenic nerve innervates the diaphragm. Stimulation causes the diaphragm to contract (increasing volume and decreasing pressure), thus causing inspiration.

Which receptors inhibit inspiration during hyperinflation of the lungs? A. pulmonary stretch receptors B. peripheral chemoreceptors C. Hypothalamic receptors D. irritant receptors

A. pulmonary stretch receptors Yes, inspiration stimulates the pulmonary stretch receptors (PSRs), which send input to the respiratory centers, inhibiting further inspiration.

A homeostatic control mechanism controls respiration. What acts as the effector(s) in this system? A. respiratory muscles B. central chemoreceptors C. peripheral chemoreceptors D. medulla oblongata

A. respiratory muscles Yes, the respiratory muscles change the volume of the thoracic cavity (and thus the pressure), resulting in inspiration and expiration.

Internal and external respiration depends on several factors. Which of the following is NOT an important factor in gas exchange? A. the molecular weight of the gas. B. partial pressure of the gases. C. available surface area. D. rate of blood flow through the tissue.

A. the molecular weight of gas Yes, molecular weight is not an important factor in gas exchange.

Barbara's cyanosis can best be explained by which of the following? A. Trauma has caused bleeding under the skin, and the accumulated blood is turning black and blue. B. The level of O2 in her blood has decreased because her breathing has stopped. C. The level of CO2 in her blood has increased because her breathing has stopped. D. Her lungs must be damaged, and as a result, the right side of her heart is sending blood to the body instead of the lungs.

B. The level of O2 in her blood has decreased because her breathing has stopped. Her alveolar P_O2 will fall, so there is less oxygen to load onto hemoglobin. In her peripheral tissues, the small amount of oxygen that hemoglobin carries will be consumed, leaving these tissues with a bluish tinge.

Which of the following statements accurately describes transpulmonary pressure? A. Transpulmonary pressure is the pressure in the alveoli during breathing phases. B. Transpulmonary pressure is usually near 4 mm Hg . C. Transpulmonary pressure is the pressure in the pleural cavity during breathing phases. D. Transpulmonary pressure reflects the pressure of air surrounding the body at any given time.

B. Transpulmonary pressure is usually near 4 mm Hgmm Hg. Transpulmonary pressure is the difference between intrapulmonary and intrapleural pressures. Because intrapleural pressure is always about 4 mm Hgmm Hg lower than the intrapulmonary pressure, transpulmonary pressure tends to remain close to 4 mm Hgmm Hg.

Which form of hypoxia reflects poor O2 delivery resulting from too few RBCs or from RBCs that contain abnormal or too little hemoglobin? A. histotoxic hypoxia B. anemic hypoxia C. hypoxemic hypoxia D. ischemic (stagnant) hypoxia

B. anemic hypoxia

Which of the following incorrectly describes mechanisms of CO2 transport? A. just over 20% of CO2 is carried in the form of carbaminohemoglobin. B. attached to the heme part of hemoglobin. C. as bicarbonate ions in plasma. D. 7-10% of CO2 is dissolved directly into the plasma

B. attached to the heme part of hemoglobin

Which of the disorders below is characterized by destruction of the walls of the alveoli producing abnormally large air spaces that remain filled with air during exhalation? A. tuberculosis B. emphysema C. coryza D. pneumonia

B. emphysema

Which of the following is an appropriate response to carbon monoxide (CO) poisoning? A. immediate application of bicarbonate ions to facilitate removal of CO from Hb. B. hyperbaric oxygen chamber to increase PO2 and clear CO from the body. C. slow breathing into a paper bag. D. hyperventilation to exhale CO from the body

B. hyperbaric oxygen chamber to increase PO2 and clear CO from the body

Hypocapnia causes ______. A. the level of bicarbonate ions in the blood to rise. B. hypoxia C. an increase in VRG activity D. hyperventilation

B. hypoxia Hypoxia occurs when too little oxygen is delivered to the tissues. Low carbon dioxide levels stimulate chemoreceptors in the brain and great vessels that signal the respiratory centers of the brain to slow down the respiratory rate. As rate falls, so does the rate of external respiration leading to lower oxygen saturation.

Respiratory control centers are located in the ________. A. midbrain and medulla B. medulla and pons C. upper spinal cord and medulla D. pons and midbrain

B. medulla and pons

Which of the following is the primary factor in oxygen's attachment to, or release from, hemoglobin? A. blood pH. B. partial pressure of oxygen. C. partial pressure of carbon dioxide. D. temperature.

B. partial pressure of oxygen Partial pressure of oxygen is the primary factor affecting the binding of oxygen with hemoglobin.

How do Barbara's recorded injuries relate to the pneumothorax? A. Her traumatic injury has caused her peripheral chemoreceptors to stop working, so they are not causing her to increase ventilation. B. When the level of O2 in the blood decreases, a negative feedback loop involving the central chemoreceptors causes lung inflation to decrease as well. C. Barbara's fractured ribs probably punctured her lung tissue and allowed air within the lung to enter the pleural cavity. D. The pain from her broken ribs is causing her to decrease breathing, so the right lung is not inflating

C. Barbara's fractured ribs probably punctured her lung tissue and allowed air within the lung to enter the pleural cavity. The most likely explanation is that air within her punctured lung entered the pleural cavity.

What directly stimulates the central chemoreceptors, thus increasing respiration? A. high pH B. low O2 (oxygen) C. H+ (hydrogen ions) D. high CO2 (carbon dioxide)

C. H+ (hydrogen ions) Yes, hydrogen ions (H+) stimulate the central chemoreceptors. CO2 is converted to H+ in the extracellular fluid of the brain.

How would the partial pressures of O2O2 and CO2CO2 change in an exercising muscle? A. The partial pressures of O2 and CO2 would remain unchanged. B. The partial pressure of O2 would increase, and the partial pressure of CO2 would decrease. C. The partial pressure of O2 would decrease, and the partial pressure of CO2 would increase.

C. The partial pressure of O2 would decrease, and the partial pressure of CO2 would increase. Yes, cells use O2 and produce CO2 during cellular respiration to produce ATP. Exercising muscles need more ATP.

Using the same graph as in Part A, what is the average number of oxygens bound to hemoglobin at a saturation of 50%? A. four B. one C. two D. three

C. Two Binding of oxygen to an individual hemoglobin protein occurs at one oxygen per hemoglobin representing 25% saturation; two oxygens per hemoglobin, 50%; three oxygens per hemoglobin, 75%; and four oxygens per hemoglobin, 100% saturation. If an average of two oxygens are bound in all hemoglobins collectively, there is 50% saturation, shown at a blood PO2 of 25 mm of Hg.

Which of the following could be responsible for an increase in intrapulmonary pressure? A. inspiration B. an increase in lung volume C. a decrease in lung volume D. a decrease in intrapleural pressure

C. a decrease in lung volume According to Boyle's law, a decrease in volume will produce an increase in pressure, at least until the air moves and pressures equalize.

Which of the following conditions or scenarios increases the respiratory rate? A. a drop in carbon dioxide levels in the blood. B. an increase in partial pressure of oxygen. C. acidosis D. alkalosis

C. acidosis A low pH in blood indicates a high level of carbon dioxide, which in turn increases the urge to ventilate the lungs.

Which of the following would likely result in a collapsed lung? A. a strong enough contraction of the diaphragm. B. a decrease in intrapulmonary pressure to atmospheric pressure. C. an opening in the chest wall that allows the intrapleural pressure to equal atmospheric pressure. D. an increase in transpulmonary pressure

C. an opening in the chest wall that allows the intrapleural pressure to equal atmospheric pressure If the chest wall is penetrated and air can enter the pleural cavity, the intrapleural pressure will no longer be negative compared to atmospheric pressure. Without a negative intrapleural pressure, there are no forces to prevent lung collapse.

What is the most powerful respiratory stimulant in a healthy person? A. arterial blood oxygen level B. oxygen needs of cells C. arterial blood carbon dioxide level D. arterial blood pH

C. arterial blood carbon dioxide level Of all the chemicals influencing respiration, CO2 is the most potent and the most closely controlled. As CO2 is hydrated in brain tissue, liberated H+ acts directly on the central chemoreceptors, causing a reflexive increase in breathing rate and depth. Low PCO2 levels depress respiration.

The Bohr effect describes the tendency for hemoglobin to more readily unload oxygen under which conditions? A. decreased pH and PCO2. B. increased pH and decreased PCO2. C. decreased pH and increased PCO2. D. increased pH and PCO2.

C. decreased pH and increased PCO2

The symptoms of hyperventilation may be averted by breathing into a paper bag because it ________. A. lowers blood pH levels. B. helps retain oxygen in the blood. C. helps retain carbon dioxide in the blood. D. reduces brain perfusion by constricting cerebral blood vessels

C. helps retain carbon dioxide in the blood

Which center is located in the pons? A. expiratory center B. pacemaker neuron center C. pontine respirator group (PRG) D. inspiratory center

C. pontine respirator group (PRG)

Which of the following stimuli is the most powerful respiratory stimulant to increase respiration? A. reduced oxygen levels B. an increase in blood pH C. rising carbon dioxide levels D. arterial pH

C. rising carbon dioxide levels Excessive carbon dioxide is a powerful stimulant to respiratory rate, as the brain assumes that when carbon dioxide levels are high, the oxygen levels must be correspondingly low.

Which of the following inhibits/reduces the respiratory rate? A. elevated carbon dioxide levels in the blood. B. partial pressure of oxygen below 60 millimeters of mercury at chemoreceptors. C. stimulation of stretch receptors in the lungs. D. a rise in body temperature.

C. stimulation of stretch receptors in the lungs The stimulation of stretch receptors in the lungs reduces the urge to inspire air. When the lungs recoil back to a relaxed shape during expiration, the urge to breathe is again initiated (inflation reflex).

What serves as the origin for the phrenic nerve? A. the sympathetic chain B. the midbrain C. the cervical plexus D. the brachial plexus

C. the cervical plexus The cervical plexus is the origin of the phrenic nerve, which descends through the thorax to innervate the diaphragm.

_______ has a greater partial pressure in the pulmonary capillaries than in the alveoli, so it diffuses into the _______. A. CO2 ; pulmonary capillaries B. O2 ; pulmonary cavities C. O2 ; alveoli D. CO2 ; alveoli

D. CO2; alveoli Yes, CO2 diffuses along its partial pressure gradient from the pulmonary capillaries into the alveoli until equilibrium is reached.

Your patient has several cracked ribs from a car accident, which of these would you expect from his or her blood gases? A. Decreased PCO2 and increased pH. B. Elevated PCO2 and increased pH. C. Decreased PCO2 and decreased pH. D. Elevated PCO2 and decreased pH.

D. Elevated PCO2 and decreased pH If he or she cannot take a deep breath, their PCO2 will elevate leading to respiratory acidosis.

Which of the following is correct regarding acclimatization? A. Decreases in arterial PO2 cause the peripheral chemoreceptors to become less responsive to increases in PCO2. B. When blood O2 levels decline, the kidneys produce more erythropoietin, which stimulates breakdown of red blood cells in the spleen. C. At high altitudes, hemoglobin's affinity for O2 is increased because BPG concentrations increase. D. High-altitude conditions always result in lower-than-normal hemoglobin saturation levels because less O2 is available to be loaded

D. High-altitude conditions always result in lower-than-normal hemoglobin saturation levels because less O2 is available to be loaded.

Which of the following best describes how Boyle's law relates to the mechanics of breathing? A. If lung volume decreases, intrapleural pressure decreases, forcing air out of the lungs. B. If lung volume decreases, intrapleural pressure increases, forcing air into the lungs. C. If lung volume increases, intrapleural pressure increases, forcing air out of the lungs. D. If lung volume increases, intrapleural pressure decreases, drawing air into the lungs.

D. If lung volume increases, intrapleural pressure decreases, drawing air into the lungs. Boyle's law shows that pressure and volume are inversely related. If the volume of a space increases, the pressure in that space must decrease.

Which of the following modifies and smoothes the respiratory pattern? A. ventral respiratory group (VRG) B. dorsal respiratory group (DRG) C. diencephalon D. pontine respiratory centers

D. pontine respiratory centers The pontine respiratory centers transmit impulses to the ventral respiratory group (VRG) of the medulla to smooth the respiratory pattern and modify it based on activities such as exercise and sleeping.

Which of the following arterial blood levels is the most powerful respiratory stimulant? A. low CO2 level B. low O2 level C. arterial pH D. rising CO2 levels

D. rising CO2 levels Of all the chemicals influencing respiration, CO2 is the most potent and the most closely controlled. An elevation of only 5 mmHg in arterial PCO2 doubles alveolar ventilation, even when arterial O2 levels and pH haven't changed. When PO2 and pH are below normal, the response to elevated PCO2 is even greater. On the other hand, arterial PO2 must drop substantially, to at least 60 mmHg, before O2 levels become a major stimulus for increased ventilation.

Which of the following is NOT a stimulus for breathing? A. acidosis resulting from CO2 retention. B. arterial PO2 below 60 mm Hg. C. rising carbon dioxide levels. D. rising blood pressure.

D. rising blood pressure

Focus your attention on the graph shown, from the left side of the Focus Figure. The percent of O2 saturation of hemoglobin is plotted (on the y-axis) against PO2 (mm Hg) (on the x-axis). Use this graph to complete Parts A-C below. On this graph, the y-axis (the vertical edge) tells you how much O2 is bound to hemoglobin (Hb). At 100%, each Hb molecule has four bound oxygen molecules. The x-axis (the horizontal edge) tells you the relative amount (partial pressure) of O2 dissolved in the fluid surrounding the Hb. If more O2 is present, more O2 is bound. However, because of Hb's properties ( O2 binding strength changes with saturation), this is an S-shaped curve, not a straight line. Which of the following represents a correct statement about data presented in the graph? A. In blood with 30% oxygen saturation of hemoglobin, there is a PO2 of ~60 mm Hg in surrounding fluid. B. Blood with three oxygens per hemoglobin represents a saturation of PO2 at ~30 mm Hg. C. In blood with 60% oxygen saturation of hemoglobin, each individual hemoglobin binds ~2.5 oxygens. D. In blood with a PO2 of 30 mm Hg, the average saturation of all hemoglobin proteins is 60%.

D. In blood with a PO2 of 30 mm Hg, the average saturation of all hemoglobin proteins is 60%. Cooperative binding of oxygen to an individual hemoglobin protein occurs with one oxygen per hemoglobin representing 25% saturation; two oxygens per hemoglobin, 50%; three oxygens per hemoglobin, 75%; and four oxygens per hemoglobin, 100% saturation. Only collectively with all hemoglobins can there be percentages in between, as seen in the S-shaped curve graph of saturation plotted against PO2 of blood.

Which statement about CO2 is FALSE? A. Its concentration in the blood is decreased by hyperventilation. B. CO2 concentrations are greater in venous blood than arterial blood. C. Its accumulation in the blood is associated with a decrease in pH. D. More CO2 dissolves in the blood plasma than is carried in the RBCs

D. More CO2 dissolves in the blood plasma than is carried in the RBCs.

Individuals with emphysema have a form of chronic obstructive pulmonary disease (COPD). As you learned, these individuals have lost the recoil in the lungs and air is therefore trapped in their lungs. Predict Steve's arterial blood pH and PaCO2 (the partial pressure of CO2 in arterial blood and dependent on exhalation). A. PaCO2 = 50 mm Hg, pH = 7.50 B. PaCO2 = 30 mm Hg, pH = 7.30 C. PaCO2 = 40 mm Hg, pH = 7.40 D. PaCO2 = 50 mm Hg, pH = 7.30

D. PaCO2 = 50 mm Hg, pH = 7.30 Alterations in the body's ability to eliminate CO2 affect the pH of the blood. Arterial blood gases, or ABGs, are often done to assess the arterial blood concentration of CO2, O2, and the blood pH.

A firefighter breathes in air normally as he enters a building following an explosion and fire. He has a meter that predicts the PO2 will approximate 15 mm Hg in his tissue fluids as he actively moves about the room. A. The S-shaped saturation curve of hemoglobin is flat at this PO2 , and O2 saturation doesn't change much with PO2 changes in mm Hg. B. The large changes in PO2 tissue environments cause only very small changes in hemoglobin O2 saturation, and no oxygen is needed. C. The firefighter is at about 10% hemoglobin O2 saturation, and he requires an external air tank. D. The firefighter's hemoglobin saturation will be about one oxygen per hemoglobin, and he will require an external air tank.

D. The firefighter's hemoglobin saturation will be about one oxygen per hemoglobin, and he will require an external air tank. An O2O2 saturation of hemoglobin of ~25% is insufficient for the firefighter moving about the room, and he should use external oxygen.

Which of the following would induce the loss of oxygen from the hemoglobin and the blood? A. increase in hemoglobin that has oxygen bound to it already. B. a decrease in blood temperature. C. decreases in plasma carbon dioxide. D. a drop in blood pH.

D. a drop in blood pH The pH in blood tends to drop when plasma reacts with carbon dioxide, a common condition in tissue. This pH drop causes weakening of the Hb-O2 bond, a phenomenon called the Bohr effect.

What is the primary form in which carbon dioxide is carried in blood? A. dissolved in plasma B. chemically bound to hemoglobin C. as carbonic acid in plasma D. as a bicarbonate ion in plasma

D. as a bicarbonate ion in plasma About 70% CO2 is transported as bicarbonate. When dissolved CO2 diffuses into RBCs, it combines with water, forming carbonic acid (H2CO3). H2CO3 is unstable and dissociates into hydrogen ions and bicarbonate (HCO3-) ions. Once generated, bicarbonate moves quickly from the RBCs into the plasma, where it is carried to the lungs.

What is the most common method of carbon dioxide transport? A. chemically bound to hemoglobin as carbaminohemoglobin. B. chemically bound to hemoglobin as oxyhemoglobin. C. dissolved in the plasma. D. as bicarbonate ions in the plasma.

D. as bicarbonate ions in the plasma Carbon dioxide reacts with water inside RBCs to form carbonic acid, which dissociates into bicarbonate and hydrogen ions. About 70% of carbon dioxide travels in the plasma as bicarbonate.

There are several types of COPD disorders. Which of the following is another example of a COPD? A. cystic fibrosis B. tuberculosis C. scoliosis D. chronic bronchitis

D. chronic bronchitis Chronic bronchitis and even asthma are characterized as obstructive lung diseases. These diseases reduce alveolar ventilation and the movement of air. They are chronic diseases characterized by coughing, wheezing, and shortness of breath. COPD is the third leading cause of death in America, and claimed the lives of 134,676 Americans in 2010. (Source: American Lung Association)

The most powerful respiratory stimulus for breathing in a healthy person is ________. A. alkalosis B. loss of oxygen in tissues C. acidosis D. increase of carbon dioxide

D. increase of carbon dioxide

Which of the choices below is NOT a factor that promotes oxygen binding to and dissociation from hemoglobin? A. temperature B. partial pressure of carbon dioxide C. partial pressure of oxygen D. number of red blood cells

D. number of red blood cells.

In the plasma, the quantity of oxygen in solution is ________. A. not present except where it is combined with carrier molecules. B. about equal to the oxygen combined with hemoglobin. C. greater than the oxygen combined with hemoglobin. D. only about 1.5% of the oxygen carried in blood

D. only about 1.5% of the oxygen carried in blood

The Bohr effect refers to the unloading of ________ in a RBC due to declining blood pH. A. carbon dioxide B. chloride ions C. BPG D. oxygen

D. oxygen