Egan's Fundamentals of Respiratory Care 10th Edition by Robert M. Kacmarek - Test Bank

Chapter 03: Patient Safety, Communication, and Record Keeping Test Bank MULTIPLE CHOICE 1. Which of the following is/are a potential area of risk to patients receiving respiratory care? a. movement or ambulation b. electrical shock c. fire hazards d. all the above ANS: C The key areas of potential risk are (1) patient movement and ambulation, (2) electrical hazards, and (3) fire hazards. DIF: Recall REF: p. 42 OBJ: 2| 3 2. Lifting heavy objects is best done with which of the following techniques? a. straight spine, bent legs b. straight spine, straight legs c. bent spine, bent legs d. bent spine, straight legs ANS: A Note that the correct technique calls for a straight spine and use of the leg muscles to lift the object. DIF: Application REF: p. 42 OBJ: 1 3. Which of the following factors are most critical in determining when a patient can be ambulated? 1. willingness of patient 2. stability of vital signs 3. absence of severe pain a. 2 and 3 b. 1 and 2 c. 1, 2, and 3 d. 1 and 3 ANS: A Ambulation should begin as soon as the patient is physiologically stable and free of severe pain. DIF: Application REF: p. 42 OBJ: 2 4. Which of the following statements is false about patient ambulation? a. Ambulation is necessary for normal body functioning. b. Patients must be carefully monitored during ambulation. c. Chairs or emergency supports must available during ambulation. d. Patients with intravenous (IV) lines should not be ambulated. ANS: D Place all equipment (e.g., intravenous [IV] equipment, nasogastric tube, surgical drainage tubes) close to the patient to prevent dislodging during ambulation. DIF: Application REF: p. 42 OBJ: 2 5. Which of the following parameters should be monitored during ambulation? 1. skin color 2. breathing rate and effort 3. level of consciousness 4. urine output a. 1 and 2 b. 3 and 4 c. 1, 2, and 3 d. 1, 2, 3, and 4 ANS: C Skin color, breathing rate and effort, and level of consciousness provide clues to how well the patient is tolerating ambulation. DIF: Application REF: p. 43 OBJ: 2 6. Which of the following terms describes the power potential behind electrical energy? a. voltage b. current c. Ohms d. resistance ANS: A Voltage is the power potential behind the electrical energy. DIF: Recall REF: p. 44 OBJ: 3 7. Which of the following is used to report electrical current? a. Ohms b. voltage c. amps d. cycles ANS: C Current is the flow of electricity from a point of higher voltage to one of lower voltage and is reported in amperes (or amps). DIF: Recall REF: p. 44 OBJ: 3 8. What is the primary factor determining the effect of an electrical shock? a. current b. temperature c. resistance d. voltage ANS: A It is important to note that current represents the greatest danger to you or your patients when electrical shorts occur. DIF: Recall REF: p. 45 OBJ: 4 9. Which of the following is/are key factor(s) determining the extent of harm caused by an electrical current? 1. duration for which the current is applied 2. path the current takes through the body 3. amount of current flowing through the body a. 1 and 2 b. 2 and 3 c. 1, 2, and 3 d. 1 and 3 ANS: C The harmful effects of current depend on (1) the amount of current flowing through the body, (2) the path it takes, and (3) the duration the current is applied. OBJ : 4 DIFF: Application REF : Pg: 45 DIF: Application REF: p. 45 OBJ: 4 10. If 120 Volts are applied to a system with 1,000 Ohms of resistance, what is the current? a. 100 amps b. 100 Ohms c. 120 milliamps d. 120 amps ANS: C The current is now calculated as amps = 120 V/1,000 Ohms = 0.12 amps or 120 milliamps. DIF: Analysis REF: p. 45 OBJ: 3 11. Which of the following organs is the most sensitive to the effects of electrical shock? a. liver b. heart c. kidneys d. lungs ANS: B Because the heart is susceptible to any current level above 100 milliamps, the 120 milliamps represents a potentially fatal shock. DIF: Recall REF: p. 45 OBJ: 4 12. In which of the following clinical situations is the normally high resistance of the skin bypassed? 1. in patients with external pacemaker wires 2. in patients with saline-filled catheters 3. in patients with intact, dry skin a. 2 and 3 b. 1, 2, and 3 c. 1 and 2 d. 3 ANS: C Current can readily flow into the body, causing damage to vital organs when the skin is bypassed via conductors such as pacemaker wires or saline-filled intravascular catheters. DIF: Application REF: p. 45 OBJ: 4 13. When a relatively high current (usually greater than 1 mA, or 1/1000 A) is applied externally to the skin, which of the following conditions exists? a. macroshock hazard b. grounding hazard c. microshock hazard d. isolation hazard ANS: A A macroshock exists when a high current (usually greater than 1 milliamp) is applied externally to the skin. DIF: Application REF: p. 46 OBJ: 4 14. When a small, usually imperceptible current (usually less than 1 mA) is allowed to bypass the skin and follow a direct, low resistance pathway into the body, which of the following conditions exists? a. macroshock hazard b. grounding hazard c. isolation hazard d. microshock hazard ANS: D A microshock exists when a small, usually imperceptible current (less than 1 milliamp) bypasses the skin and follows a direct, low-resistance path into the body. DIF: Application REF: p. 46 OBJ: 4 15. High amperage (6 amps or more) applied externally to the skin can cause which of the following? 1. sustained myocardial contraction 2. respiratory paralysis 3. skin burns a. 1 and 2 b. 2 and 3 c. 1, 2, and 3 d. 1 and 3 ANS: C Table 3-1 summarizes the different effects of these two types of electrical shock. DIF: Recall REF: p. 47 OBJ: 4 16. Which of the following currents passing through the chest can cause ventricular fibrillation, diaphragm dysfunction (due to severe, persistent contraction), and death? a. 100 mA b. 100 A c. 100 μA d. 10 μA ANS: A Higher currents (exceeding 100 milliamps [mA]) that pass through the chest can cause ventricular fibrillation, diaphragm dysfunction (due to severe, persistent contraction), and death. Table 3-1 summarizes the different effects of these two types of electrical shock. DIF: Analysis REF: p. 45 OBJ: 4 17. What is the primary purpose of grounding all electrical equipment used in the hospital setting? a. to prevent the dangerous buildup of voltage in the equipment b. to make the equipment more secure and less likely to break down c. to avoid excessive energy costs d. to convert electrical power from DC to AC ANS: A In these cases, the third (ground) wire prevents the dangerous buildup of voltage that can occur on the metal frames of some electrical equipment. DIF: Application REF: p. 46 OBJ: 3 18. Where do most hospital fires initially start? a. clinical laboratory b. kitchen c. electrical engineering post d. patient’s room ANS: B About 90% of fires in health care facilities occur in hospitals and the most common site for the origin of the fire is the kitchen. DIF: Recall REF: p. 47 OBJ: 6 19. Which of the following is true about fires in oxygen-enriched atmospheres? 1. They are more difficult to put out. 2. They burn more quickly. 3. They burn more intensely a. 1 and 2 b. 2 and 3 c. 1 and 3 d. 1, 2, and 3 ANS: D Fires in oxygen-enriched atmospheres are larger, more intense, faster burning, and more difficult to extinguish. DIF: Application REF: p. 47 OBJ: 7 20. Which of the following conditions must be met for a fire to occur? 1. temperature high enough for combustion 2. presence of oxygen 3. presence of flammable material a. 1 and 2 b. 2 and 3 c. 1 and 3 d. 1, 2, and 3 ANS: D For a fire to start, three conditions must exist: (1) flammable material must be present, (2) oxygen must be present, and (3) the flammable material must be heated to or above its ignition temperature. DIF: Application REF: p. 48 OBJ: 7 21. Which of the following statements is/are true regarding the use of oxygen? 1. Oxygen is flammable. 2. Oxygen accelerates the rate of combustion. 3. Increased oxygen concentration accelerates the rate of combustion. a. 1 and 2 b. 2 and 3 c. 1 and 3 d. 1, 2, and 3 ANS: B Although oxygen is nonflammable, it greatly accelerates the rate of combustion. Burning speed increases with an increase in either the concentration or partial pressure of oxygen. DIF: Recall REF: p. 48 OBJ: 7 22. How can the risk of fire because of static electrical discharge in the presence of oxygen be minimized? a. Use only wool or polyester fabrics in the area of use. b. Keep oxygen concentrations well below 21%. c. Maintain high relative humidity in the area of use. d. Keep oxygen in high-pressure storage cylinders. ANS: C The minimal risk that may be present can be further reduced by maintaining high relative humidity (greater than 60%). DIF: Application REF: p. 48 OBJ: 7 23. In the standard approach to hospital fires, the RACE plan has been suggested. What does the letter “C” stand for in this approach? a. capture b. contain c. call for help d. collapse ANS: B The third step is to contain the fire as much as possible by closing doors and turning oxygen zone valves off. DIF: Application REF: p. 48 OBJ: 7 24. Nonverbal communication includes all of the following except: a. gesture b. touch c. discussion d. space ANS: C Nonverbal communication includes gestures, facial expressions, eye movements and contact, voice tone, space, and touch. DIF: Recall REF: p. 49 OBJ: 9 25. Which of the following components of communication is a method used to transmit messages? a. sender b. channel c. receiver d. feedback ANS: B The channel of communication is the method used to transmit messages. DIF: Application REF: p. 49 OBJ: 9 26. Which of the following is a method for communicating empathy to your patients? 1. use of touch 2. use of key words 3. use of eye contact 4. use of the authority a. 1, 2, and 3 b. 1 and 3 c. 1, 2, 3, and 4 d. 2, 3, and 4 ANS: A The use of touch and proper eye contact can demonstrate genuine concern for your patient. Key words and phrases such as “I understand” can let the patient know you are listening and interested. DIF: Application REF: p. 50 OBJ: 9 27. Which of the following factors can have an impact on the outcomes of therapeutic communication between patient and practitioner? 1. verbal and nonverbal components of expression 2. environmental factors (e.g., noise, privacy) 3. values and beliefs of both patient and practitioner 4. sensory and emotional factors (e.g., fear, pain) a. 1, 2, and 3 b. 1 and 3 c. 1, 2, 3, and 4 d. 2, 3, and 4 ANS: C Many factors affect communication in the health care setting (Figure 3-11). DIF: Application REF: p. 50 OBJ: 9 28. Basic purposes of communication include all of the following except: a. change others’ values orientation b. obtain or relay information c. give instructions (teach) d. persuade others to take action ANS: A Key purposes of communication are summarized in Box 3-1. DIF: Application REF: p. 51 OBJ: 11 29. All of the following techniques can be used to improve one’s effectiveness as a sender of messages except: a. share information rather than telling b. emphasize agreement over disagreement c. eliminate threatening behavior d. use effective nonverbal communication ANS: B Others will not always agree with what you say. Do not become defensive when others disagree with you; simply try to understand their perspective and be open to their input. DIF: Application REF: p. 52 OBJ: 12 30. All of the following techniques can be used to improve one’s listening skills except: a. resist distractions b. maintain composure and control emotions c. keep an open mind (be objective) d. judge the sender’s delivery, not the content ANS: D The content of what is being said is the issue to focus on. How it is delivered is not that important. Some people are more articulate than others but the message is most important. DIF: Application REF: p. 52 OBJ: 12 31. Maintaining eye contact, leaning toward the patient, and nodding your head are all good examples of what communication technique? a. clarifying b. empathizing c. attending d. reflecting ANS: C Attending involves the use of gestures and posture that communicate one’s attentiveness. Attending also involves confirming remarks such as, “I see what you mean.” DIF: Application REF: p. 52 OBJ: 12 32. Techniques to help ensure that understanding is taking place between the parties involved in an interaction include which of the following? 1. clarifying 2. paraphrasing 3. perception checking 4. attending a. 1, 2, and 3 b. 1 and 3 c. 1, 2, 3, and 4 d. 2, 3, and 4 ANS: C All four techniques can be useful to enhance communication. DIF: Application REF: p. 52 OBJ: 12 33. A therapist who says “Please explain that to me again” to a patient during an interview is using what interpersonal communication technique? a. clarifying b. paraphrasing c. perception checking d. reflecting feelings ANS: A Requesting clarification lets the patient know you are trying to understand him or her. DIF: Recall REF: p. 52 OBJ: 12 34. A patient’s response to an interview question is initially unclear. Which of the following responses on your part would be most appropriate? a. “Please go on.” b. “You seem to be anxious.” c. “Please explain that to me again.” d. “Yes, I think I understand.” ANS: C Requesting clarification is done by asking the patient to explain his or her thought again. DIF: Application REF: p. 52 OBJ: 12 35. A therapist who says “You seem to be anxious about your surgery” to a patient just admitted for bypass surgery is using what interpersonal communication technique? a. clarifying b. paraphrasing c. perception checking d. reflecting feelings ANS: D Reflecting feelings is the process of telling patients about how you perceive their feelings. It encourages patients to discuss their feelings further. DIF: Application REF: p. 53 OBJ: 11 36. Key barriers to effective interpersonal communication include all of the following except: a. use of symbols or words with different meanings b. value systems that are different or not accepted c. similar perceptions of the problem d. feelings of personal insecurity by one or both parties ANS: C Similar perceptions of the problem promote communication and are not a barrier. DIF: Application REF: p. 52 OBJ: 13 37. Which of the following strategies for conflict resolution represents a middle-ground strategy that combines assertiveness and cooperation? a. avoiding b. competing c. compromising d. accommodating ANS: C Compromising is a middle-ground strategy that combines assertiveness and cooperation. DIF: Recall REF: p. 54 OBJ: 13 38. What form of patient record is most designed to succinctly report data in a time-oriented format and to decrease time needed for documentation? a. subjective, objective, assessment, and plan (SOAP) record b. problem-oriented, medical record (POMR) record c. flowsheet d. progress note ANS: C Flowsheets are designed to briefly report data and to decrease time spent in documentation. DIF: Recall REF: p. 55 OBJ: 14 39. The elements of a POMR entry would include which of the following? 1. patient’s subjective complaints and concerns 2. objective data gathered by the health professional 3. assessment of the subjective and objective data 4. plan to address the identified problem(s) a. 1, 2, and 3 b. 1 and 3 c. 1, 2, 3 and 4 d. 1, 3, and 4 ANS: C The POMR progress notes contain the findings (subjective and objective data), assessment, plans, and orders of the doctors, nurses, and other practitioners involved in the care of the patient. The format used is often referred to as SOAP. “S” = subjective information; “O” = objective information; “A” = assessment; “P” = plan of care. DIF: Application REF: p. 58 OBJ: 14 40. Information about a patient’s nearest kin, physician, and initial diagnosis can be found in which section of the medical record? a. history and physical exam b. admission sheet c. physician’s orders d. consultation sheet ANS: B See Box 3-3. DIF: Recall REF: p. 55 OBJ: 14 41. To confirm a physician’s prescription for a drug that you need to give to a patient, you would go to which section of the medical record? a. history and physical exam b. laboratory sheet c. physician’s orders d. medication record ANS: C See Box 3-3. DIF: Recall REF: p. 55 OBJ: 14 42. To determine the most recent medical status of a patient whom you are about to start treating, you would go to which section of the medical record? a. progress sheet b. nurses’ notes c. physician’s orders d. history and physical exam ANS: A See Box 3-3. DIF: Recall REF: p. 55 OBJ: 14 43. To find out what drugs or intravenous fluids a patient has received recently, you would go to which section of the medical record? a. progress sheet b. nurses’ notes c. physician’s orders d. medication record ANS: D See Box 3-3. DIF: Recall REF: p. 55 OBJ: 14 44. What is a time-based record of measurement during a specialized procedure such as mechanical ventilation? a. consultation sheet b. specialized flowsheet c. progress notes d. graphic sheet ANS: B See Box 3-3. DIF: Recall REF: p. 55 OBJ: 14 45. A pulmonary specialist has been called in by an internist to examine a patient and help make a diagnosis. Where in the patient’s medical record would you look for the pulmonary specialist’s report? a. progress sheet b. consultation sheet c. physician’s orders d. history and physical exam ANS: B See Box 3-3. DIF: Recall REF: p. 55 OBJ: 14 46. To determine any recent trends in a patient’s pulse, respiration, or blood pressure, you would go to which section of the medical record? a. progress sheet b. nurses’ notes c. anesthesia record d. vital signs sheet ANS: D See Box 3-3. DIF: Recall REF: p. 55 OBJ: 14 47. To check on the results of a patient’s recent blood work, you would go to which section of the medical record? a. vital signs sheet b. laboratory sheet c. flowsheet d. progress notes ANS: B See Box 3-3. DIF: Recall REF: p. 55 OBJ: 14 48. To determine the amount of urine excreted by a patient in the last 24 hours, you would go to which section of the medical record? a. vital signs sheet b. laboratory sheet c. nurses’ notes d. intake and output (I & O) sheet ANS: D See Box 3-3. DIF: Recall REF: p. 55 OBJ: 14 49. Which of the following is the correct way to sign a medical record entry? a. CAW, LRCP, CRT b. CAW, Respiratory Department c. C. White, LRCP, CRT d. Cathy White, Therapist, Respiratory Department ANS: C See Box 3-4. DIF: Application REF: p. 58 OBJ: 15 50. Which of the following is an acceptable practice in medical recordkeeping? a. leaving blank lines b. erasing incorrect entries c. using ditto marks d. using standard abbreviations ANS: D See Box 3-4. DIF: Recall REF: p. 58 OBJ: 15 51. If you make a mistake when charting a patient treatment, what should you do? a. Make a new entry (called “correction”) just below the mistake. b. Erase the mistake and have your supervisor countersign it. c. Draw a line through the mistake and write “error” above it. d. Have your supervisor make the chart correction later. ANS: C See Box 3-4. DIF: Recall REF: p. 58 OBJ: 15 52. Which of the following are unacceptable practices in medical recordkeeping? 1. specifying when you will return to provide patient therapy 2. providing your own interpretation of a patient’s symptoms 3. recording the patient’s complaints and general behavior 4. charting several separate tasks under a single chart entry a. 2 and 4 b. 1 and 2 c. 1 and 4 d. 1, 2, and 4 ANS: A See Box 3-4. DIF: Recall REF: p. 58 OBJ: 15 53. What is the role of the RT during a disaster situation? a. transporting the critically ill patients to safety first b. shutting of the main oxygen supply in the hospital c. getting themselves to safety d. going to look for a backup generator ANS: A Part of the RT’s role of disaster preparedness includes transport and transfer of the critically ill patients. DIF: Application REF: p. 48 OBJ: 8 54. A patient who is on a ventilator is going to be transported to MRI. Which of the following is the most important piece of equipment to have available in the MRI suite? a. a MRI compatible ventilator b. laboratory flowsheet c. intubation box d. sedatives ANS: A The RT needs to have an MRI-compatible ventilator available and set up in the MRI suite. DIF: Analysis REF: p. 49 OBJ: 8 55. All health care personnel must use the “two patient identifiers” before initiating care, which include all of the following, except? a. patient name b. patient birth date c. patient medical record number d. patient room number ANS: D All health care personnel must use the “two patient identifiers” before initiating care, which include patient name, birth date, and medical record number DIF: Application REF: p. 50 OBJ: 10 56. Medical records are strictly confidential and are protected under what law? a. HIPPA b. HESSA c. Record’s law d. Patriot Act ANS: A Medical records are strictly confidential and are protected under the Health Insurance and Portability Act (HIPPA). DIF: Recall REF: p. 54 OBJ: 15 57. What was one of the Joint Commission’s (TJC) goals for 2010? a. to improve accuracy of patient identification b. to lessen costs c. to enforce proper infection control d. to have more case studies ANS: A TJC’s goals for 2010 were to improve accuracy of patient identification. DIF: Recall REF: p. 50 OBJ: 10 58. Improper storage or handling of medical gas cylinders can result in which of the following? 1. increased risk of fire 2. explosive releases of high pressure gas 3. toxic effects of some gases 4. a contained environment a. 1, 2 and 4 b. 1 and 2 c. 1 and 4 d. 1, 2, and 3 ANS: D All of the above and result from improper storage and handling of medical gas cylinders. DIF: Recall REF: p. 49 OBJ: 8 59. Which group or organizations regulates the storage of medical gases? a. NBRC b. National Fire Protection Association (NFPA) c. The Joint Commission (TJC) d. HIPPA ANS: B National Fire Protection Association (NFPA) regulates the storage of medical gases. Monitoring is done by the Joint Commission. DIF: Recall REF: p. 49 OBJ: 8 60. An RT is instructing a patient on a particular piece of equipment, and should use which scenario on educating the patient? a. Call Back b. Read Back c. Teach Back d. A short quiz ANS: C A Teach Back scenario will be helpful for the RT to know if the patient understands what is being explained regarding equipment use. DIF: Application REF: p. 51 OBJ: 12 Chapter 06: Physical Principles of Respiratory Care Test Bank MULTIPLE CHOICE 1. Which of the following statements about liquids is NOT true? a. They exhibit the phenomenon of flow. b. They assume the shape of their container. c. They are difficult to compress. d. They expand to fill their container. ANS: D Liquid molecules also exhibit mutual attraction. However, because these forces are much weaker in liquids than in solids, liquid molecules can move about freely (Figure 6-1, B). This freedom of motion explains why liquids take the shape of their containers and are capable of flow. However, like solids, liquids are dense and cannot easily be compressed or expanded. DIF: Application REF: p. 103 OBJ: 1 2. Which of the following statements correctly describe(s) gases? 1. Gases exhibit the phenomenon of flow. 2. Molecular forces of attraction are minimal. 3. Gases are easily compressible. 4. Gases expand to fill their container. a. 1 and 2 b. 1, 2, and 3 c. 2, 3, and 4 d. 1, 2, 3, and 4 ANS: D In a gas, molecular attractive forces are very weak. Thus, gas molecules, which lack restriction to their movement, exhibit rapid, random motion with frequent collisions (Figure 6-1, C). Gases have no inherent boundaries and are easily compressed and expanded. Moreover, like liquids, gases can flow. DIF: Application REF: p. 103 OBJ: 1 3. At what temperature does all kinetic activity of matter cease? a. 0°K b. 0°C c. 32°C d. 0°F ANS: A The SI (Systeme Internationale) units for temperature are degrees Kelvin, with a zero point equal to absolute zero (0°K). DIF: Recall REF: p. 105 OBJ: 3 4. A patient has a recorded body temperature of 106° F. What is this temperature in degrees Celsius? a. 41°C b. 98°C c. 39°C d. 22°C ANS: A To convert degrees Fahrenheit to degrees Celsius, use the following formula: °C = 5/9 × (° F – 32). DIF: Analysis REF: p. 106 OBJ: 3 5. A near-drowning patient has a recorded body temperature of 30° C. What is the equivalent temperature in degrees Fahrenheit? a. –4°F b. 86°F c. 32°F d. 77°F ANS: B To convert degrees Celsius to degrees Fahrenheit, simply reverse the formula given in question 4: ° F = (9/5 × ° C) + 32. DIF: Analysis REF: p. 106 OBJ: 3 6. By which of the following means can the internal energy of a substance be increased? 1. cooling the substance 2. performing work on the substance 3. heating the substance a. 2 and 3 b. 1 and 2 c. 2 d. 1, 2, and 3 ANS: A You can increase the internal energy of an object by heating it or by performing work on it. DIF: Application REF: p. 104 OBJ: 2 7. What term is used for the transfer of heat by the direct interaction of atoms or molecules in a hot area with atoms or molecules in a cooler area? a. radiation b. convection c. condensation d. conduction ANS: D Conduction is the transfer of heat by direct contact between hot and cold molecules. DIF: Recall REF: p. 104 OBJ: 2 8. Which of the following would be the worst heat conductor? a. water b. glass c. air d. copper ANS: C With fewer molecular collisions than in solids and liquids, gases exhibit low thermal conductivity. DIF: Application REF: p. 104 OBJ: 2 9. What is the primary means by which heat transfer occurs in fluids? a. convection b. radiation c. conduction d. evaporation ANS: A Heat transfer in both liquids and gases occurs mainly by convection. DIF: Application REF: p. 104 OBJ: 2 10. Which of the following is a good clinical example of using the principle of convection to transfer heat? a. humidifiers with immersion heaters b. heated, enclosed infant incubators c. wire-heated pneumotachometers d. heated ventilator exhalation valves ANS: B This is the principle behind forced-air heating in houses and convection heating in infant incubators. OB: 2 DIFF: Application DIF: Application REF: p. 104 OBJ: 2 11. Which of the following methods of heat transfer requires no direct contact between the warmer and cooler substances? a. conduction b. convection c. evaporation d. radiation ANS: D While conduction and convection require direct contact between two substances, radiant heat transfer occurs without direct physical contact. DIF: Application REF: p. 104 OBJ: 2 12. Which of the following would help to decrease a patient’s loss of body heat? 1. Increase the temperature of the room. 2. Increase the exposed skin surface area. 3. Move the patient away from cold windows. a. 1 and 2 b. 2 and 3 c. 1, 2, and 3 d. 1 and 3 ANS: D In simple terms, for an object with a given emissivity, the larger the surface area (relative to mass) and the lower the surrounding temperature, the greater is the radiant heat loss per unit time. DIF: Application REF: p. 105 OBJ: 2 13. Which of the following is FALSE about evaporation? a. Evaporation is a type of vaporization. b. The process of evaporation warms the surrounding air. c. Evaporation is the change of a liquid substance into a gas. d. For evaporation to occur, heat energy is needed. ANS: B Vaporization is the change of state from liquid to gas. Vaporization requires heat energy. According to the first law of thermodynamics, this heat energy must come from the surroundings. In one form of vaporization, called evaporation, heat is taken from the air surrounding the liquid, thereby cooling the air. DIF: Application REF: p. 105 OBJ: 5 14. What is the physical process whereby the gaseous form of a substance is changed back into its liquid state? a. condensation b. sublimation c. vaporization d. radiation ANS: A During condensation, a gas turns back into a liquid. DIF: Application REF: p. 105 OBJ: 4 15. Which of the following is/are TRUE of liquids? 1. They are hard to compress. 2. They exert pressure. 3. They exert buoyant force. 4. They conform to their containers. a. 2 and 4 b. 1, 2, and 3 c. 1 and 3 d. 1, 2, 3, and 4 ANS: D Liquids exhibit flow and assume the shape of their container. Liquids also exert pressure, which varies with depth and density. Variations in liquid pressure within a container produce an upward supporting force, called buoyancy. DIF: Application REF: p. 107 OBJ: 1 16. Which of the following equations can be used to calculate the pressure exerted by a liquid? a. liquid pressure = liquid depth ÷ liquid density b. liquid pressure = liquid depth × surface area c. liquid pressure = liquid density × liquid viscosity d. liquid pressure = liquid density × liquid depth ANS: D The pressure exerted by a liquid depends on both its height (depth) and weight density (weight per unit volume), which is shown in equation form: PL = h × dw. DIF: Analysis REF: p. 107 OBJ: 4 17. According to Pascal’s principle, the pressure exerted by a liquid in a container depends on which of the following? 1. depth of the liquid 2. density of the liquid 3. shape of the container a. 1, 2, and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3 ANS: B The pressure exerted by a liquid depends on both its height (depth) and weight density (weight per unit volume), which is shown in equation form: PL = h × dw. DIF: Application REF: p. 107 OBJ: 4 18. Archimedes’ principle is applied clinically in which of the following devices? a. nebulizer b. capillary tube c. hydrometer d. humidifier ANS: C Clinically, Archimedes’ principle is used to measure the specific gravity of certain liquids. A hydrometer is used to measure the specific gravity of certain liquids. DIF: Application REF: p. 108 OBJ: 4 19. What is the internal force that opposes the flow of fluids (equivalent to friction between solid substances)? a. conductivity b. kinetic energy c. viscosity d. density ANS: C Viscosity is the force opposing a fluid’s flow. DIF: Recall REF: p. 108 OBJ: 4 20. Which of the following is FALSE about viscosity? a. The greater the viscosity, the greater is the opposition to flow. b. Viscosity is most important under conditions of turbulent flow. c. The stronger the cohesive forces, the greater the viscosity. d. Fluid viscosity is equivalent to friction between solids. ANS: B Laminar flow consists of concentric layers of fluid flowing parallel to the tube wall at velocities that increase toward the center. DIF: Application REF: p. 108 OBJ: 4 21. After placing a liquid into a small-diameter glass tube, you observe the formation of a convex (upwardly curved) meniscus. What conclusion is correct? a. The liquid must have a very low surface tension. b. Strong adhesive forces exist between the liquid and glass. c. The liquid must have an extremely high viscosity. d. Strong cohesive forces exist among the liquid molecules. ANS: D When the liquid is water, the meniscus is concave because the water molecules at the surface adhere to the glass more strongly than they cohere to each other. In contrast, a mercury meniscus is convex. In this case, the cohesive forces pulling together the mercury atoms exceed the adhesive forces trying to attract the mercury to the glass. DIF: Application REF: p. 109 OBJ: 4 22. What force is responsible for the spherical shape of liquid droplets and their ability to keep this shape when placed into an aerosol suspension? a. cohesion b. adhesion c. viscosity d. surface tension ANS: D Surface tension is a force exerted by like molecules at a liquid`s surface. A small drop of fluid provides a good illustration of this force. As shown in Figure 6-8, cohesive forces affect molecules inside the drop equally from all directions. However, only inward forces affect molecules on the surface. This imbalance in forces causes the surface film to contract into the smallest possible surface area, usually a sphere or curve (meniscus). This phenomenon explains why liquid droplets and bubbles retain a spherical shape. DIF: Application REF: p. 109 OBJ: 4 23. Which of the following liquids has the lowest surface tension? a. whole blood b. ethyl alcohol c. plasma d. mercury ANS: B Ethyl alcohol has the lowest surface tension of the listed liquids. Table 6-2 lists the surface tensions of selected liquids in dynes/cm (cgs). DIF: Recall REF: p. 109 OBJ: 4 24. Which of the following is FALSE about liquid bubbles? a. The smaller the bubble, the greater is the necessary inflation pressure. b. Inflation pressure can be lowered if surface tension is increased. c. The smaller the bubble, the greater is surface tension pressure. d. When connected, small bubbles tend to empty into larger bubbles. ANS: B The equation for a liquid bubble follows: P = 4ST ÷ r where P is the pressure in the bubble, ST is the surface tension, and r is the bubble radius. Figure 6-9 demonstrates this relationship for two bubbles of different sizes, each with the same surface tension. DIF: Application REF: p. 110 OBJ: 4 25. What is the phenomenon whereby a liquid in a small tube tends to move upward against the force of gravity? a. capillary action b. shear stress c. surface tension d. buoyancy ANS: A Capillary action is a phenomenon in which a liquid in a small tube moves upward, against gravity. DIF: Recall REF: p. 110 OBJ: 4 26. Which of the following is/are good clinical examples of the principle of capillary action? 1. capillary stick blood samples 2. absorbent humidifier wicks 3. certain surgical dressings a. 1, 2, and 3 b. 1 and 2 c. 2 and 3 d. 2 ANS: A Capillary action is the basis for blood samples obtained by use of a capillary tube. The absorbent wicks used in some gas humidifiers are also an application of this principle, as are certain types of surgical dressings. DIF: Application REF: p. 111 OBJ: 4 27. What is the temperature at which the vapor pressure of a liquid equals the pressure exerted on the liquid by the surrounding atmosphere? a. boiling point b. dew point c. triple point d. melting point ANS: A The boiling point of a liquid is the temperature at which its vapor pressure equals atmospheric pressure. DIF: Recall REF: p. 111 OBJ: 4 28. Which of the following is/are TRUE about boiling? 1. Boiling a liquid requires more energy than does evaporating it. 2. A liquid’s boiling point varies with the atmospheric pressure. 3. The greater the ambient pressure, the lower is the boiling point. a. 2 and 3 b. 1 and 3 c. 1 and 2 d. 1, 2, and 3 ANS: C Because the weight of the atmosphere retards the escape of vapor molecules, the greater the ambient pressure, the greater is the boiling point. DIF: Application REF: p. 111 OBJ: 4 29. What is the change in state of a substance from liquid to gaseous form occurring below its boiling point? a. evaporation b. sublimation c. boiling d. vaporization ANS: A A liquid also can change into a gas at temperatures lower than its boiling point through a process called evaporation. DIF: Application REF: p. 111 OBJ: 4 30. Which of the following is/are TRUE about molecular water vapor? 1. Water vapor exhibits kinetic activity. 2. Molecular water vapor can be seen. 3. Water vapor exerts pressure. a. 1 and 2 b. 2 and 3 c. 1, 2, and 3 d. 1 and 3 ANS: D To be distinguished from visible particulate water, such as mist or fog, this invisible gaseous form of water is called molecular water. Molecular water obeys the same physical principles as other gases and therefore exerts a pressure called water vapor pressure. DIF: Application REF: p. 111 OBJ: 5 31. What occurs during the evaporation of water? a. The adjacent air is warmed. b. The adjacent air is cooled. c. The water temperature rises. d. Heat is given up to the air. ANS: B As the surrounding air loses heat energy, it cools. This is the principle of evaporation cooling. DIF: Recall REF: p. 111 OBJ: 5 32. What is the equilibrium condition in which a gas holds all the water vapor molecules that it can? a. Evaporation b. Stabilization c. Saturation d. body humidity ANS: C At this point, the air over the water is saturated with water vapor. However, vaporization does not stop once saturation occurs. DIF: Recall REF: p. 111 OBJ: 5 33. Which of the following methods would increase the rate of evaporation of a container of water? 1. Increase the temperature of the surrounding air. 2. Decrease the pressure of the surrounding air. 3. Increase the temperature of the water. a. 1 and 2 b. 2 and 3 c. 1 and 3 d. 1, 2, and 3 ANS: D The warmer the air, the more vapor it can hold. Specifically, the capacity of air to hold water vapor increases with temperature. The warmer the air making contact with a water surface, the faster is the rate of evaporation. DIF: Application REF: p. 111 OBJ: 5 34. Which of the following represents a direct measure of the kinetic activity of water vapor molecules? a. absolute humidity b. water vapor pressure c. percent body humidity d. relative humidity ANS: B Water vapor pressure represents the kinetic activity of water molecules in air. DIF: Application REF: p. 111 OBJ: 5 35. What is the term for the actual content or weight of water present in a given volume of air? a. percent body humidity b. water vapor pressure c. absolute humidity d. relative humidity ANS: C Absolute humidity can be measured by weighing the water vapor extracted from air using a drying agent. DIF: Application REF: p. 112 OBJ: 6 36. What is the absolute humidity (water vapor content) of saturated gas at normal body temperature (37°C)? a. 47.0 mg/L b. 37.0 mg/L c. 98.6 mg/L d. 43.8 mg/L ANS: D For example, air that is fully saturated with water vapor at 37° C and 760 mm Hg has a water vapor pressure of 47 mm Hg and an absolute humidity of 43.8 mg/L. DIF: Recall REF: p. 112 OBJ: 6 37. What is the water vapor pressure of saturated gas at normal body temperature (37°C)? a. 47.0 mm Hg b. 43.8 mm Hg c. 37.0 mm Hg d. 98.6 mm Hg ANS: A For example, air that is fully saturated with water vapor at 37°C and 760 mm Hg has a water vapor pressure of 47 mm Hg and an absolute humidity of 43.8 mg/L. DIF: Recall REF: p. 112 OBJ: 6 38. What is the term for the ratio of the actual water vapor present in a gas compared with the capacity of that gas to hold the vapor at a given temperature? a. relative humidity b. absolute humidity c. water vapor pressure d. percent body humidity ANS: A When a gas is not fully saturated, its water vapor content can be expressed in relative terms using a measure called relative humidity. DIF: Application REF: p. 112-113 OBJ: 6 39. At a room temperature of 22°C, air has the capacity to hold 19.4 mg/L of water vapor. If the absolute humidity in the air is 7.4 mg/L, then what is the relative humidity (RH)? a. 45% b. 58% c. 70% d. 38% ANS: D If the absolute humidity is 7.4 mg/L, then the RH is calculated as follows: %RH = 7.4 mg/L ÷ 19.4 mg/L × 100 %RH = 0.38×100 %RH = 38% DIF: Analysis REF: p. 113 OBJ: 6 40. When the water vapor content of a volume of gas equals its capacity, what is the relative humidity (RH) of this gas? a. 80% b. 100% c. 40% d. 60% ANS: B When the water vapor content of a volume of gas equals its capacity, the RH is 100%. When the RH is 100%, a gas is fully saturated with water vapor. DIF: Application REF: p. 112 OBJ: 6 41. A gas at 50° C with a relative humidity of 100% is cooled to 37° C. Which of the following will occur? 1. condensation on surfaces 2. visible droplet formation 3. warming of the adjacent air a. 1, 2, and 3 b. 1 and 2 c. 1 and 3 d. 2 and 3 ANS: A Condensed moisture deposits on any available surface, such as on the walls of a container or delivery tubing, or even on particles suspended in the gas. Condensation returns heat to and warms the surrounding environment, whereas vaporization of water cools the adjacent air. DIF: Analysis REF: p. 113 OBJ: 6 42. What is the term for the temperature at which the water vapor in a gas begins to condense back into a liquid? a. triple point b. critical pressure c. dew point d. boiling point ANS: C The temperature at which condensation begins is called the dew point. DIF: Recall REF: p. 113 OBJ: 6 43. What occurs when the temperature of a saturated gas drops down to its dew point? a. Excess water vapor will condense as visible droplets. b. The temperature of the surrounding air decreases. c. Any liquid water present will quickly evaporate. d. The relative humidity of the gas begins to decrease. ANS: A Cooling a saturated gas below its dew point causes increasingly more water vapor to condense into liquid water droplets. DIF: Application REF: p. 113 OBJ: 6 44. The American National Standards Institute has set a water vapor content level of 30 mg/L as the minimum absolute humidity required for patients whose upper airways have been bypassed. This equals what body humidity (BH)? a. 68% b. 47% c. 75% d. 100% ANS: A The %BH of a gas is the ratio of its actual water vapor content to the water vapor capacity in saturated gas at body temperature (37° C). Thus, %BH is the same as relative humidity, except that the capacity (or denominator) is fixed at 43.8 mg/L. DIF: Analysis REF: p. 112-113 OBJ: 6 45. If the absolute humidity in a medical gas being delivered to a patient is 14 mg/L, then what is the body humidity (BH)? a. 7% b. 16% c. 24% d. 32% ANS: D The %BH of a gas is the ratio of its actual water vapor content to the water vapor capacity in saturated gas at body temperature (37° C). Thus %BH is the same as RH, except that the capacity (or denominator) is fixed at 43.8 mg/L. DIF: Analysis REF: p. 112-113 OBJ: 6 46. What is the term for the ratio of the amount of water vapor in a volume of gas compared to the amount of the water in gas saturated at a normal body temperature of 37°C? a. percent body humidity (BH) b. relative humidity (RH) c. absolute humidity d. water vapor pressure ANS: A The %BH of a gas is the ratio of its actual water vapor content to the water vapor capacity in saturated gas at body temperature (37°C). Thus, %BH is the same as RH, except that the capacity (or denominator) is fixed at 43.8 mg/L. DIF: Application REF: p. 113 OBJ: 6 47. Which of the following properties of gases distinguish them from liquids—that is, are unique to the gaseous phase of matter? 1. Gases fill the available space. 2. Gases exhibit viscosity. 3. Gases exert pressure. 4. Gases are readily compressed. 5. Gases are capable of flow. a. 2, 3, 4, and 5 b. 1, 3, and 4 c. 2, 3, and 4 d. 1 and 4 ANS: D Unlike liquids, gases are readily compressed and expanded and fill the spaces available to them by diffusion. DIF: Application REF: p. 114 OBJ: 1 48. Which of the following occurs when the temperature of a gas rises? 1. The kinetic activity of the gas increases. 2. The rate of molecular collisions increases. 3. The pressure exerted by the gas rises. a. 1, 2, and 3 b. 1 and 2 c. 2 and 3 d. 3 ANS: A The velocity of gas molecules is directly proportional to temperature. As a gas is warmed, its kinetic activity increases, its molecular collisions increase, and its pressure rises. DIF: Recall REF: p. 114 OBJ: 7 49. According to Avogadro’s law, which of the following is/are TRUE? 1. One gram of any substance contains the same number of particles. 2. Equal volumes of gases at standard temperature, standard pressure, dry (STPD) have the same number of molecules. 3. Equal numbers of gas molecules at STPD occupy the same volume. a. 1 and 2 b. 1, 2, and 3 c. 2 and 3 d. 1 ANS: D Avogadro’s law states that the 1-g atomic weight of any substance contains exactly the same number of atoms, molecules, or ions. DIF: Recall REF: p. 114 OBJ: 7 50. In International System (SI) units, what is any quantity of matter that contains 6.023 × 1023 atoms, molecules, or ions? a. pound (lb) b. gram (g) c. ounce (oz) d. mole (mol) ANS: D One mole of a gas, at a constant temperature and pressure, should occupy the same volume as 1 mole of any other gas. This ideal volume is termed the molar volume. DIF: Recall REF: p. 114 OBJ: 7 51. According to Avogadro’s law, under standard conditions of temperature and pressure (0°C and 760 mm Hg), 1 mole of any gas occupies which of the following? a. 1.34 L b. 22.40 L c. 7.48 L d. 28.30 L ANS: B At standard temperature and pressure, dry (STPD), the ideal molar volume of any gas is 22.4 L. DIF: Analysis REF: p. 114 OBJ: 7 52. What is the density of a mixture of 40% oxygen and 60% helium at STPD? a. 0.34 g/L b. 0.55 g/L c. 0.68 g/L d. 1.25 g/L ANS: C For the density of a gas mixture to be calculated, the percentage or fraction of each gas in the mixture must be known. For example, to calculate the density of air at STPD, the following equation is used: dwair = (FN2 × gmw N2) + (FO2 × gmw O2) ÷ 22.4 L dwair = (0.79 × 28) + (0.21 × 32) ÷ 22.4 L dwair = 1.29 g/L DIF: Analysis REF: p. 115 OBJ: 7 53. What is the physical process whereby atoms or molecules tend to move from an area of higher concentration or pressure to an area of lower concentration or pressure? a. Sublimation b. Melting c. Diffusion d. capillary action ANS: C Diffusion is the process whereby molecules move from areas of high concentration to areas of lower concentration. DIF: Application REF: p. 115 OBJ: 7 54. According to Graham’s law, which of the following gases would diffuse most quickly? Gas density a. W 1.432 g/L b. X 0.543 g/L c. Y 0.834 g/L d. Z 1.213 g/L ANS: B Mathematically, the rate of diffusion of a gas is inversely proportional to the square root of its gram molecular weight. According to this principle, lighter gases diffuse rapidly, whereas heavy gases diffuse more slowly. Moreover, because diffusion is based on kinetic activity, anything that increases molecular activity will quicken diffusion; thus, heating and mechanical agitation speed diffusion. DIF: Analysis REF: p. 115 OBJ: 7 55. Which of the following best describes the physical concept of pressure? a. weight ÷ unit volume b. mass × acceleration c. force × distance d. force ÷ unit area ANS: D Pressure is a measure of force per unit area. DIF: Application REF: p. 115 OBJ: 7 56. What is the common British unit of pressure? a. Newton (N)/m2 b. dyne/cm2 c. Pascal (Pa) d. lb/in2 (psi) ANS: D Pounds per square inch (lb/in2), or “psi,” is the British fps pressure unit. DIF: Recall REF: p. 115 OBJ: 7 57. A mercury barometer reads 770 mm Hg. What is the actual atmospheric pressure in g/cm2? a. 14.7 g/cm2 b. 1034.0 g/cm2 c. 1020.0 g/cm2 d. 1047.0 g/cm2 ANS: D At sea level, the average atmospheric pressure will support a column of mercury 76 cm (760 mm) or 29.9 inches in height. If we also know that mercury has a density of 13.6 g/cm3 (0.491 lb/in3), then the average atmospheric pressure (PB) is calculated as follows: cgs units: PB = 77 cm × 13.6 g/cm3 = 1047 g/cm2 . DIF: Analysis REF: p. 116 OBJ: 7 58. One atmosphere (1 atm) of pressure is equivalent to which of the following? 1. 29.9 inches Hg 2. 14.7 lb/in2 3. 1034.0 g/cm2 4. 760.0 mm Hg a. 1, 2, and 3 b. 2 and 4 c. 1 and 3 d. 1, 2, 3, and 4 ANS: D At sea level, the average atmospheric pressure will support a column of mercury 76 cm (760 mm) or 29.9 inches in height. If we also know that mercury has a density of 13.6 g/cm3 (0.491 lb/in3), then the average atmospheric pressure (PB) is calculated as follows: cgs units: PB = 76 cm × 13.6 g/cm3 = 1034 g/cm2 fps units: PB = 29.9 in × 0.491 lb/in3 = 14.7 lb/in2 DIF: Analysis REF: p. 116 OBJ: 7 59. You obtain a mercury barometric reading of 760 mm Hg at 17°C. Using the following factor table, compute the corrected pressure. ° C 740 750 760 17 2.17 2.20 2.23 18 2.29 2.32 2.35 19 2.38 2.41 2.44 a. 223.0 mm Hg b. 747.7 mm Hg c. 757.8 mm Hg d. 762.3 mm Hg ANS: C The U.S. Weather Bureau provides temperature correction factors for barometric readings (see Appendix 1). DIF: Analysis REF: p. 116 OBJ: 7 60. The peak pressure on a ventilator reads 40 cm H2O. What is the equivalent pressure in mm Hg? a. 37.0 mm Hg b. 29.6 mm Hg c. 68.3 mm Hg d. 4.9 mm Hg ANS: B Because of mercury’s high density (13.6 g/cm3), it assumes a height that is easy to read for most pressures in the clinical range. Water columns can also be used to measure pressure (in cm H2O), but only low pressures. Because water is 13.6 times less dense than mercury, 1 atm. DIF: Analysis REF: p. 116 OBJ: 7 61. The peak pressure on a ventilator reads 30 cm H2O. What is the equivalent pressure in kilopascals (kPa)? a. 37.0 kPa b. 68.0 kPa c. 4.9 kPa d. 2.9 kPa ANS: D One kPa equals approximately 10.2 cm H2O or 7.5 mm Hg. DIF: Analysis REF: p. 117 OBJ: 7 62. From a bedside capnograph (CO2 measuring device), you obtain a “dry” gas reading of 5.3% CO2 in a patient’s exhaled gas. Given a barometric pressure of 765 mm Hg, what is the partial pressure of CO2 in this patient’s exhaled gas? a. 347 mm Hg b. 41 mm Hg c. 164 mm Hg d. 35 mm Hg ANS: B Dalton’s law describes the relationship among the partial pressure and the total pressure in a gas mixture. According to this law, the total pressure of a mixture of gases must equal the sum of the partial pressures of all component gases. Moreover, the principle states that the partial pressure of a component gas must be proportional to its percentage in the mixture. DIF: Analysis REF: p. 117 OBJ: 7 63. In the lung’s alveoli, there are four gases mixed together: oxygen, carbon dioxide, nitrogen, and water vapor. At a normal barometric pressure of 760 mm Hg, alveolar O2 exerts a partial pressure of 100 mm Hg, CO2 40 mm Hg, and water vapor 47 mm Hg. What is the alveolar partial pressure of nitrogen? a. 187 mm Hg b. 713 mm Hg c. 660 mm Hg d. 573 mm Hg ANS: D Dalton’s law describes the relationship among the partial pressure and the total pressure in a gas mixture. According to this law, the total pressure of a mixture of gases must equal the sum of the partial pressures of all component gases. Moreover, the principle states that the partial pressure of a component gas must be proportional to its percentage in the mixture. DIF: Analysis REF: p. 117 OBJ: 7 64. Which of the following factors determine how much of a given gas can dissolve in a liquid? 1. solubility coefficient of the gas 2. temperature of the liquid 3. gas pressure above the liquid a. 2 and 3 b. 1 and 2 c. 1 and 3 d. 1, 2, and 3 ANS: D Henry’s law predicts how much of a given gas will dissolve in a liquid. According to this principle, at a given temperature, the volume of a gas that dissolves in a liquid is equal to its solubility coefficient times its partial pressure. DIF: Application REF: p. 118 OBJ: 7 65. At 37° C and 760 mm Hg pressure, 0.023 ml of O2 can be dissolved in 1 ml of plasma, whereas at the same temperature and pressure, 0.510 ml of CO2 will dissolve in 1 ml of plasma. What explains this difference? a. CO2 diffuses more rapidly than O2. b. CO2 is more soluble in plasma than O2. c. CO2 has a greater molecular weight than O2. d. O2 has less affinity for plasma than CO2. ANS: B For example, the solubility coefficient of oxygen in plasma, at 37° C and 760 torr pressure, is 0.023 ml/ml. Under the same conditions, 0.510 ml of CO2 can dissolve in 1 ml of plasma. DIF: Application REF: p. 118 OBJ: 7 66. Which of the following will occur when a gas undergoes expansion? 1. The pressure of the gas increases. 2. Molecular collisions decrease. 3. The gas temperature increases. a. 1 and 2 b. 2 and 3 c. 2 d. 1 and 3 ANS: C If a gas-filled container could be enlarged, the gas would expand to occupy the new volume. Figure 6-19 illustrates the concepts of gas compression and expansion. DIF: Application REF: p. 118 OBJ: 7 67. If a given mass of a gas is maintained at a constant temperature, what will decreasing its pressure do? a. decrease its volume b. increase its mass c. increase its volume d. decrease its mass ANS: C If a gas-filled container could be enlarged, the gas would expand to occupy the new volume. Figure 6-19 illustrates the concepts of gas compression and expansion. DIF: Application REF: p. 119 OBJ: 7 68. In what processes of gas compression or expansion does the temperature remain constant? a. isothermal b. adiabatic c. hypothermal d. neutral kinetic ANS: A During isothermal conditions, the temperature of an ideal gas should not change with either expansion or contraction. DIF: Recall REF: p. 121 OBJ: 7 69. Both a compressed gas cylinder and its regulator are at room temperature with all valves in the off position. After the cylinder is opened and gas begins flowing, you note that the regulator is extremely cold to touch. Which of the following principles best explains this observation? a. adiabatic compression b. Gay-Lussac’s law c. Joule-Thompson effect d. Venturi principle ANS: C The rapid expansion of real gases causes substantial cooling. This phenomenon of expansion cooling is called the Joule-Thompson Effect Adiabatic compression can also occur in gas delivery systems where rapid compression occurs within a fixed container. The rise in temperature caused by this rapid compression can ignite any combustible material in the system. It is for this reason that RTs must take care to clear any combustible matter from high-pressure gas delivery systems before pressurization. DIF: Application REF: p. 121 OBJ: 7 70. Respiratory therapists must ensure that any oil or dust is cleared from high-pressure medical-gas delivery systems before pressurization. Why is this action needed? a. Inhaled dust particles can cause pneumoconiosis. b. The oil or dust can cause a leak in the system. c. Oil or dust does not easily mix with medical gases. d. Adiabatic compression could ignite the oil or dust. ANS: D DIF: Application REF: p. 121 OBJ: 7 71. Which of the following occurs when water vapor is added to a dry gas at a constant pressure? 1. The volume occupied by the gas mixture increases. 2. The relative humidity of the mixture increases. 3. The partial pressure of the original gas is reduced. a. 1 and 2 b. 1, 2, and 3 c. 1 and 3 d. 3 ANS: B The dry volume of a gas at a constant pressure and temperature is always smaller than its saturated volume. The opposite is also true. Correcting from the dry state to the saturated state always yields a larger gas volume. The pressure exerted by water vapor is independent of the other gases with which it mixes, depending only on the temperature and RH. Therefore, the addition of water vapor to a gas mixture always lowers the partial pressures of the other gases present. DIF: Application REF: p. 120 OBJ: 7 72. During some pulmonary function tests, saturated gas exhaled from a patient’s lungs is gathered at room temperature. Which of the following correction-factor tables would you use to determine what volume this gas occupied in the patient’s lungs? a. standard temperature, standard pressure, dry (STPD) to body temperature, ambient pressure, saturated (BTPS) b. BTPS to STPD c. ambient temperature, ambient pressure, saturated (ATPS) to BTPS d. ATPS to STPD ANS: C Correction from ATPS to standard temperature and pressure (0° C and 760 torr), dry (STPD). DIF: Application REF: p. 120 OBJ: 7 73. Which of the following are true of the behavior of gases at very low temperatures or very high pressures? 1. The actual volume of the gas molecules becomes important. 2. Intermolecular attractive forces have greater impact. 3. Gases begin to deviate from their “ideal” behavior. a. 1, 2, and 3 b. 1 and 2 c. 1 and 3 d. 2 and 3 ANS: A At very low temperatures, kinetic activity lessens and these forces become more important. Likewise, very low pressures permit gas molecules to move freely about with little mutual attraction. DIF: Application REF: p. 120 OBJ: 7 74. For every liquid there is a temperature above which the kinetic activity of its molecules is so great that the attractive forces cannot keep them in a liquid state. This temperature is called the: a. critical temperature b. melting point c. flash temperature d. triple point ANS: A When a liquid is heated to its critical temperature, it converts to a gas. This temperature is called the critical temperature. DIF: Application REF: p. 121 OBJ: 4 75. Which of the following is a FALSE statement about oxygen? a. No pressure can keep it in a liquid state above –118.8°C. b. Below its boiling point, it remains liquid at ambient pressure. c. Its critical temperature is above normal room temperature. d. It cannot be turned into a liquid at room temperature. ANS: C Liquid oxygen is produced by separating it from a liquefied air mixture at a temperature below its boiling point or critical temperature (–183°C or –297°F). After it is separated from air, the oxygen must be maintained as a liquid by being stored in insulated containers below its boiling point. As long as the temperature does not exceed –183°C, the oxygen will remain liquid at atmospheric pressure. If higher temperatures are needed, higher pressures must be used. If at any time the liquid oxygen exceeds its critical temperature of –118.8°C, it will convert immediately to a gas. DIF: Application REF: p. 121 OBJ: 7 76. Which of the following medical gases can be maintained in the liquid form at room temperature? 1. nitrous oxide 2. carbon dioxide 3. Oxygen 4. Helium a. 1 and 2 b. 2, 3, and 4 c. 2 and 3 d. 2 and 4 ANS: A Both CO2 and N2O have critical temperatures above normal room temperature (Table 6-5). DIF: Recall REF: p. 121 OBJ: 7 77. What temperature is necessary to liquefy oxygen at 1 atm pressure? a. –118.8° C b. –181.1° F c. –463.3° F d. –183.0° C ANS: D Liquid oxygen is produced by separating it from a liquefied air mixture at a temperature below its boiling point (–183°C or –297°F). After it is separated from air, the oxygen must be maintained as a liquid by being stored in insulated containers below its boiling point. As long as the temperature does not exceed –183°C, the oxygen will remain liquid at atmospheric pressure. If higher temperatures are needed, higher pressures must be used. If at any time the liquid oxygen exceeds its critical temperature of –118.8°C, it will convert immediately to a gas. DIF: Recall REF: p. 121 OBJ: 7 78. With all else equal, under which of the following conditions would the drop in pressure occurring while a fluid flows through a tube be greatest? Tube Diameter Fluid Viscosity A. A Small Low B. B Large Low C. C Large High D. D Small High a. A; Small; Low b. B; Large; Low c. C; Large; High d. D; Small; High ANS: D Available energy decreases because frictional forces oppose fluid flow. Frictional resistance to flow exists both within the fluid itself (viscosity) and between the fluid and the tube wall. In general, the greater the viscosity of the fluid and the smaller the cross-sectional area of the tube, the greater the drop in pressure along the tube. DIF: Analysis REF: p. 122 OBJ: 8 79. The resistance to flow of a fluid through a tube can be computed according to which of the following formulas? a. resistance = flow × viscosity b. resistance = flow ÷ pressure c. resistance = pressure ÷ flow d. resistance = flow × pressure ANS: C For any given tube length, flow resistance equals the difference in pressure between the two points along the tube divided by the actual flow. This is expressed as a formula: R = (P1 – P2) ÷ V DIF: Application REF: p. 122 OBJ: 8 80. What is the pattern of flow in which a fluid moves in discrete cylindrical streamlines? a. Transitional b. Turbulent c. Laminar d. Tracheal ANS: C During laminar flow, a fluid moves in discrete cylindrical layers or streamlines. OB J: 8 DIFF: Application DIF: Application REF: p. 122 OBJ: 8 81. According to Poiseuille’s law, the pressure needed to drive a fluid through a tube will increase under which of the following conditions? 1. increased fluid viscosity 2. decreased tube length 3. decreased rate of flow 4. decreased tube radius a. 1 and 2 b. 2, 3, and 4 c. 1 and 4 d. 1, 3, and 4 ANS: C The difference in pressure required to produce a given flow, under conditions of laminar flow through a smooth tube of fixed size, is defined by Poiseuille’s law: P = 8nl/r4 ,where P is the driving pressure gradient, n is the viscosity of the fluid, l is the tube length, is the fluid flow, r is the tube radius, and and 8 are constants. OBJ : 8 DIFF: Application DIF: Application REF: p. 122 OBJ: 8 82. Under conditions of turbulent flow, what is the driving pressure? a. proportional to the square of the flow b. inversely proportional to the flow c. linearly proportional to the flow d. inversely proportional to the density ANS: A This changeover from laminar to turbulent flow depends on several factors, including fluid density (d), viscosity (h), linear velocity (v), and tube radius (r). In combination, these factors determine Reynold’s number (NR): NR = v × d × 2r/h DIF: Application REF: p. 123 OBJ: 8 83. Which of the following conditions tend to cause laminar flow to become turbulent (producing a high Reynold’s number)? 1. high linear gas velocity 2. high gas density 3. low gas viscosity 4. large tube diameter a. 2, 3, and 4 b. 2 and 3 c. 1, 2, and 4 d. 1, 2, 3, and 4 ANS: D In a smooth-bore tube, laminar flow becomes turbulent when NR exceeds 2000 (the number is dimensionless). According to the previous formula, conditions favoring turbulent flow include increased fluid velocity, increased fluid density, increased tube radius, or decreased fluid viscosity. In the presence of irregular tube walls, turbulent flow can occur when NR is less than 2000. DIF: Recall REF: p. 123 OBJ: 7 84. Assuming a constant flow, what will happen to a fluid if the cross-sectional area of the tube in which it flows decreases? a. Its velocity will increase. b. Its velocity will decrease. c. Its density will decrease. d. Its viscosity will decrease. ANS: B Throughout the tube, the fluid flows at a constant rate of 5 L/min. At point A, with a cross-sectional area of 5.08 cm2, the velocity of the fluid is 16.4 cm/sec. At point B, the cross-sectional area of the tube decreases to 2.54 cm2, half its prior value. At this point, the velocity of the fluid doubles to 32.8 cm/sec. DIF: Application REF: p. 124 OBJ: 8 85. According to Bernoulli’s principle, as a fluid flows through a narrow passage or stricture, which of the following will occur? 1. Fluid velocity will decre