Fill-in-the-Blank/Short Answer Questions
1) Type II alveolar cells secrete ________.
5) The ________ regulates smoothing of transitions from inspiration to expiration.
7) The cartilaginous flap that closes the trachea during swallowing is called the ________.
11) How is alveolar gas exchange affected by emphysema and pneumonia?
Answer: With pneumonia, if the lungs become edematous, the thickness of the exchange membrane may increase dramatically, restricting gas exchange, and body tissues begin to suffer from hypoxia. With emphysema, the lungs become progressively less elastic and more fibrous, which hinders both inspiration and expiration. Gas exchange remains adequate initially, but muscular activity must be enlisted to expire. Additionally, a symptom of emphysema is fusion of alveoli, resulting in less surface area for gas exchange.
12) Briefly differentiate between atmospheric pressure, intrapulmonary pressure, and intrapleural pressure. Which of these is always negative in a healthy individual during normal breathing? What happens if intrapleural pressure becomes equal to atmospheric pressure?
Answer: Atmospheric pressure is the pressure exerted by gases of the atmosphere. Intrapulmonary pressure is the pressure within the alveoli of the lungs. Intrapleural pressure is the pressure within the intrapleural space. Intrapleural pressure is negative relative to the other two during normal inspiration/expiration. Equalization of the intrapleural pressure with atmospheric pressure or intrapulmonary pressure immediately causes lung collapse.
13) The contraction of the diaphragm and the external intercostal muscles begins inspiration. Explain exactly what happens, in terms of volume and pressure changes in the lungs, when these muscles contract.
Answer: With contraction of the diaphragm, the height of the thoracic cavity increases. Contraction of the intercostal muscles expands the diameter of the thorax. With an increase in volume of the thorax, the intrapulmonary volume increases, causing a drop in pressure relative to atmospheric pressure. Air rushes into the lungs along this pressure gradient until intrapulmonary and atmospheric pressures are equal.
14) What is the chloride shift and why does it occur?
15) If a baby is born at 28 weeks' gestation, what major problem will the doctors look for?
16) How is it possible to change the pitch of our voice from high to low?
17) The partial pressure gradient for oxygen (in the body) is much steeper than that for carbon dioxide. Explain how equal amounts of these two gases can be exchanged (in a given time interval) in the lungs and at the tissues.
18) Define anatomical dead space. What is the relationship between anatomical and alveolar dead space? Which value is likely to increase during lung pathology?
19) Distinguish among anemic, ischemic, histotoxic, and hypoxemic hypoxia.
Answer: Anemic hypoxia reflects poor oxygen delivery resulting from too few RBCs or RBCs that contain abnormal or too little Hb. Ischemic hypoxia results when blood circulation is impaired or blocked. Histotoxic hypoxia occurs when body cells are unable to use O2 even though adequate amounts are delivered. Hypoxemia hypoxia is indicated by reduced arterial PO2.
1) Timothy has been having difficulty breathing since he had pneumonia last month. Recently he had severe pain in his chest and back, and his breathing was extremely irregular. The doctor at the emergency room told him that one of the lobes of his lung had collapsed. How could this happen?
2) While having a physical examination, a young male informed his doctor that at age 8 he had lobar pneumonia and pleurisy in his left lung. The physician decided to measure his VC. Describe the apparatus and method used for taking this measurement. Define the following terms used in the description of lung volumes: TV, IRV, ERV, RV, and VC.
Answer: His vital capacity (VC) was measured using a spirometer. As he breathed into a mouthpiece, a hollow bell, inverted over water, was displaced, giving a graphic recording on a rotating drum. Tidal volume (TV) is the amount of air that moves into and out of the lungs with normal breathing. Inspiratory reserve volume (IRV) is the amount of air that can be forcibly inhaled beyond the tidal volume. The expiratory reserve volume (ERV) is the amount of air that can be evacuated from the lungs over and above a tidal expiration. Residual volume (RV) is the amount of air that remains in the lungs even after the most strenuous expiration. Vital capacity (VC) is the total amount of exchangeable air.
3) Jane had been suffering through a severe cold and was complaining of a frontal headache and a dull, aching pain at the side of her face. What regions are likely to become sites of secondary infection following nasal infection?
4) A smoker sees his doctor because he has a persistent cough and is short of breath after very little exertion. What diagnosis will the doctor make and what can the person expect if he does not quit smoking?
Answer: The person is suffering from chronic bronchitis, which causes the dyspnea and coughing. If he does not stop smoking, he can expect frequent pulmonary infections, more coughing, and progressively worse dyspnea (all symptoms of chronic obstructive pulmonary disease). Ultimately, he can expect to develop hypoxemia, CO2 retention, and respiratory acidosis. He may develop emphysema or lung cancer.
5) After a long scuba diving session on a Caribbean reef, Carl boards a plane to Dallas. He begins to feel pain in his elbow on the flight back to Dallas. What is happening to him?
Answer: Carl is experiencing the bends due to several problems: (1) Applying Boyle's law, a lot of gas was forced into Carl's bloodstream during the dive and there was not sufficient time to decompress the excess before he boarded the plane. (2) The plane is not pressurized to sea level, which further reduced atmospheric pressure holding the gases in suspension (Henry's law). Carl will have to be transported to a hyperbaric chamber to be repressurized. This will reduce the volume of the gas bubbles in his arm so that normal circulation can resume.
6) A patient was admitted to the hospital with chronic obstructive pulmonary disease. His PO2 was 55 and PCO2 was 65. A new resident orders 54% oxygen via the venturi mask. One hour later, after the oxygen was placed, the nurse finds the patient with no respiration or pulse. She calls for a Code Blue and begins cardiopulmonary resuscitation (CPR). Explain why the patient stopped breathing.
Answer: In people who retain carbon dioxide because of pulmonary disease, arterial PCO2 is chronically elevated and chemoreceptors become unresponsive to this chemical stimulus. In such cases, declining PO2 levels act on the oxygen-sensitive peripheral chemoreceptors and provide the principle respiratory stimulus, or the so-called hypoxic drive. Pure oxygen will stop a person's breathing, because his respiratory stimulus (low PO2 levels) would be removed.
7) While dining out in a restaurant a man suddenly chokes on a piece of meat. The waitress is also a student nurse and comes to the man's aid. She asks him if he can talk. The man responds by shaking his head no and grabbing at his neck. What is the significance of the man's inability to talk?
8) How will the lungs compensate for an acute rise in the partial pressure of CO2 in arterial blood?
9) A patient with tuberculosis is often noncompliant with treatment. Explain why this may happen.
10) John has undergone surgery and has developed pneumonia. He also has a history of emphysema. Which assessment parameters would the nurse expect to find?