Download LEARNING OBJECTIVE 1: List the general functions of the

CHAPTER 19
RESPIRATORY SYSTEM
LEARNING OBJECTIVE 1: List the general functions of the respiratory system.
Lecture Suggestions and Guidelines
1. Briefly introduce the organs of the respiratory system.
2. Describe respiration as the entire process by which gases are exchanged between the atmosphere and the body
cells.
3. Introduce the breathing mechanism.
4. Discuss the control of breathing.
5. Describe gas exchange and transport.
Application Question(s)
1. Provide students with a diagram of the human body and ask them to label the organs of the respiratory system
and explain the function of each organ.
Answer: The diagram should include the nostril, sinus, nasal cavity, hard palate, soft palate, oral cavity,
pharynx, epiglottis, larynx, trachea, bronchus, and lung.
Critical Thinking Issue(s)
1. Compose a list of the students’ thoughts as to the most frequent and serious diseases of the lung. Briefly discuss
each disease listed.
Answer: The list would most likely include pneumonia, chronic obstructive pulmonary disease, asthma,
bronchiogenic carcinoma, trauma, and upper respiratory diseases, such as the common cold and hay fever.
LEARNING OBJECTIVE 2: Name and describe the locations of the organs of the respiratory system.
and
LEARNING OBJECTIVE 3: Describe the functions of each organ of the respiratory system.
Lecture Suggestions and Guidelines
1. Lecture on the names, locations, and functions of the nose, nasal cavity, sinuses, pharynx, larynx, trachea,
bronchial tree and lungs.
2. Describe the nasal septum and nasal conchae.
3. Locate and describe the paranasal sinuses.
4. Describe the three subdivisions of the pharynx.
5. Discuss the cartilages associated with the larynx and describe the epiglottis and glottis.
6. Define tracheostomy.
7. Describe the branches of the bronchial tree, the structure and function of the respiratory tubes, and the functions
of alveoli.
8. Discuss the structure and function of the lungs, including the hilus, visceral pleura, parietal pleura, pleural
cavity, and lobules.
Application Question(s)
1. What are the major effects of cigarette smoking on the respiratory system?
Answer: Ask students to prepare a short report. Responses will vary.
Critical Thinking Issue(s)
1. Divide the class into two groups for debate. Choose a controversial issue regarding smoking, for example,
legislation which prohibits smoking from all public places, lowering the legal age for purchasing cigarettes, or
waging a heavy sin tax on cigarette sales which would support public school funding.
Answer: Responses will vary.
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LEARNING OBJECTIVE 4: Explain how inspiration and expiration are accomplished.
Lecture Suggestions and Guidelines
1. Introduce the concept of inspiration.
2. Describe the role of atmospheric pressure, intra-alveolar pressure, surface tension, and surfactant upon
inspiration.
3. Discuss expiration. Include the origin of the forces of expiration.
4. Describe how expiration is aided by thoracic and abdominal wall muscles.
Application Question(s)
1. Dissect a sheep pluck, which comprises the trachea, lungs, and heart. What are the interrelationships among the
respiratory system, the cardiovascular system, the muscular system, and the nervous system.
Answer: Lungs oxygenate blood and excrete carbon dioxide as blood is pumped by the heart through the lungs,
the respiratory system is aided by contracting muscles to rid the body of carbon dioxide, and the pH of the
internal environment is controlled, in part, by the respiratory system.
Critical Thinking Issue(s)
1. Define the terms dyspnea, apnea, and orthopnea, and give examples of each.
Answer: All three terms are indicative of changes in breathing patterns. Dyspnea relates to difficult breathing.
A crushing blow to the chest may result in dyspnea if a fractured rib punctures a lung. Apnea is a general term
used to describe a complete lack of breathing. Patients who experience sleep apnea may suddenly awaken
gasping for breath. Orthopnea is a dyspnea due to lying down. Asthma sufferers may sometimes find it
impossible to breathe normally in a horizontal position.
LEARNING OBJECTIVE 5: Name and define each of the respiratory air volumes and capacities.
and
LEARNING OBJECTIVE 6: Explain how the alveolar ventilation rate is calculated.
Lecture Suggestions and Guidelines
1.
2.
3.
4.
5.
6.
7.
Describe a respiratory cycle.
Discuss tidal volume, inspiratory reserve volume, and expiratory reserve volume.
Lecture on inspiratory capacity, functional residual capacity, vital capacity, and total lung capacity.
Define residual air.
Discuss the formula used to calculate minute ventilation.
Describe alveolar ventilation rate calculations in terms of tidal volume and breathing rate.
Describe alveolar ventilation rate as a major factor affecting gas exchange.
Application Question(s)
1. Give the names, volumes, and descriptions of eight respiratory air volumes and capacities. Write the name of
each on one side of an index card. On the reverse side, list the average volume and a description of each.
Answer: The students should create one index card for each of the following: TV, IRV, ERV, RV, IC, FRC,
VC, and TLC.
Critical Thinking Issue(s)
1. Calculate the minute respiratory volume and alveolar ventilation rate, given the following information: tidal
volume = 525 ml, breathing rate = 10 breaths per minute, physiologic dead space = 150 ml.
Answer: Minute respiratory volume = 5,250 ml per minute, alveolar ventilation rate = 3,750 ml per minute.
LEARNING OBJECTIVE 7: List several nonrespiratory air movements and explain how each occurs.
Lecture Suggestions and Guidelines
1.
2.
3.
4.
Describe the mechanisms and functions of coughing and sneezing.
Compare the mechanisms and functions of laughing and crying.
Discuss hiccuping, yawning and speaking as nonrespiratory air movements.
Discuss the nonrespiratory air movements used to express emotions and those used to clear the air passages.
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Application Question(s)
1. What kinds of stimuli may trigger a cough?
Answer: The function of a cough is to clear the lower respiratory passages. Stimuli may include food, which
has entered the respiratory tract, mucus accumulation, inhalation of an irritant or allergen, smoke or other air
pollutants, or a tumor.
Critical Thinking Issue(s)
1. Why should fluids not be administered orally to an unconscious person?
Answer: The cough reflex is “disengaged” during unconsciousness and fluids may enter the larynx, trachea,
and lungs.
LEARNING OBJECTIVE 8: Locate the respiratory center and explain how it controls normal
breathing.
and
LEARNING OBJECTIVE 9: Discuss how various factors affect the respiratory center.
Lecture Suggestions and Guidelines
1.
2.
3.
4.
Describe the location of the respiratory membrane.
Discuss the two groups of neurons responsible for medullary rythmicity.
Lecture on the regulation of breathing rate by the pneumotaxic area.
Discuss factors, which affect breathing, including chemicals, lung tissue stretching, and emotional state.
Application Question(s)
1. What are the sympathetic and parasympathetic effects on the respiratory system?
Answer: Emotional excitement or stress stimulates a sympathetic response. Rapid, deep breathing is the result
of bronchiole dilation. On the other hand, a parasympathetic response, when the body is resting, would constrict
the bronchioles.
Critical Thinking Issue(s)
1. Ask the students to prepare a short report on SIDS, in terms of effects upon the cardiovascular system, red
blood cell production, and hormone production.
Answer: Research has shown that sudden infant death syndrome results in an enlarged heart, smooth muscle
changes in pulmonary arteries, an increase in red blood cell production, and an increase in the glucocorticoid
hormone called cortisol.
LEARNING OBJECTIVE 10: Describe the structure and function of the respiratory membrane.
Lecture Suggestions and Guidelines
1.
2.
3.
4.
Describe how gas exchanges between the air and the blood occur within the alveoli.
Describe the structure and function of alveoli.
Discuss gas exchange through the alveolar and capillary walls.
Lecture on diffusion through the respiratory membrane.
Application Question(s)
1. What major factors affect breathing? Discuss the factor involved, receptors stimulated, the response, and the
effect of each.
Answer: Responses should include a discussion of tissue stretching, blood oxygen levels, blood carbon dioxide
levels, and CSF hydrogen ion concentration.
Critical Thinking Issue(s)
1. Compare and contrast the signs and symptoms of chronic bronchitis and emphysema.
Answer: Chronic bronchitis results in a persistent cough, excess mucus, chest pain, dyspnea, fever and chills,
wheezing, right heart failure, and hypoxia. Emphysema results in enlargement of alveolar air spaces, barrel
chest, dyspnea, rales, and difficult exhalation.
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LEARNING OBJECTIVE 11: Explain how the blood transports oxygen and carbon dioxide.
Lecture Suggestions and Guidelines
1. Discuss the transport of oxygen in combination with hemoglobin molecules.
2. Define oxyhemoglobin.
3. Explain the increase in oxygen release due to increased blood concentration of carbon dioxide, increased blood
acidity, and increased blood temperature.
4. Describe the formation of carbon monoxide.
5. Lecture on the toxicity of carbon monoxide.
6. Discuss ways in which carbon dioxide may be transported.
7. Describe the role of carbonic anhydrase.
8. Describe the dissociation of carbonic acid to release hydrogen ions and bicarbonate ions.
Application Question(s)
1. While driving on a long, winter vacation in the twenty-year old family car, you discover that your son and
daughter are complaining of severe headaches. Upon further investigation, they seem confused and exhibit a
cherry red complexion. What could be a possible cause of their symptoms, why is the condition dangerous, and
what do you do next?
Answer: The children may be suffering from carbon monoxide poisoning caused by a faulty car exhaust
system. The condition is dangerous because carbon monoxide competes directly with oxygen for binding sites
on hemoglobin molecules. The victims need fresh air immediately and possibly 100% oxygen treatment at the
nearest medical facility.
Critical Thinking Issue(s)
1. Compare the chemical mechanisms of external and internal respiration.
Answer: External respiration involves the conversion of bicarbonate ion and hydrogen ion to carbonic acid.
Carbonic acid is then broken down into carbon dioxide and water. Internal respiration is the preceding
mechanism in reverse. Carbon dioxide and water combine to form carbonic acid, which is then broken down
into hydrogen ion and bicarbonate ion.
LEARNING OBJECTIVE 12: Review the major events of cellular respiration.
and
LEARNING OBJECTIVE 13: Explain how cells use oxygen.
Lecture Suggestions and Guidelines
1.
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3.
4.
5.
6.
7.
Give an overview of anaerobic respiration, glycolysis, and the synthesis of ATP.
Reiterate the process of aerobic respiration.
Describe the structures and functions of ATP molecules and ADP molecules.
Summarize the citric acid cycle.
Summarize ATP synthesis by oxidative phosphorylation.
Describe ways in which organelles use oxygen to release energy from nutrient molecules.
Reiterate the use of oxygen in the release of energy from glucose molecules.
Application Question(s)
1. Ask students to sketch a flowchart depicting the major events of aerobic respiration.
Answer: The flowchart should include mentioning that this phase takes place in the mitochondria and transfers
energy to ATP. Glucose breaks down, carbon dioxide and hydrogen remain. Carbon dioxide diffuses out of the
cell (waste), and hydrogen combines with oxygen to form water.
Critical Thinking Issue(s)
1. How does location differ between the processes of anaerobic and aerobic respiration?
Answer: Anaerobic respiration occurs in the cytosol, whereas aerobic respiration occurs in the mitochondria.
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RELATED DISEASES OF HOMEOSTATIC INSTABILITY
1. Asthma—Labored breathing due to spasms of the bronchi along with increased mucus secretions. Causes may
be due to hypersensitivity to allergens, neurogenic, chemical, or behavioral. The patient experiences wheezing,
difficulty in breathing, and is subject to respiratory infections.
2. Cystic Fibrosis—A genetic disorder resulting in an excessive mucus secretion of the lungs causing decreased
gas exchange. Patients perspire large amounts of sodium chloride that can be detected by a sweat chloride test.
Excess mucus also impairs the digestive capabilities of the pancreas. Loss of lung function may result over
time.
3. Atelectasis—Collapse of a lung caused by changes in pressure. The patient may experience pneumothorax.
This condition may come about by obstruction of the airway. Some common obstructions include marbles,
stones, and pennies.
SUGGESTIONS FOR ADDITIONAL READING
Alland, David, et al. June 16, 1994. Transmission of tuberculosis in New York City: An analysis by DNA
fingerprinting and conventional epidemiologic methods. New England Journal of Medicine, vol. 330. By using
DNA fingerprinting methods on people with the same infection, medical sleuths can determine routes of
transmission among individuals.
Colten, H.R. March 30, 1995. Airway inflammation in cystic fibrosis. New England Journal of Medicine, vol. 332.
Daily ibuprofen may help dampen inflammation in the lungs of cystic fibrosis patients.
Ganterbain, Douglas. October 1993. The high life. Discover. Why do mountains kill some people—it make them so
ill they may wish they were dead—while leaving others quite unscathed?
Hamburg, M.A., and T.R. Frieden. June 16, 1994. Tuberculosis transmission in the 1990s. New England Journal of
Medicine, vol. 330. An old scourge emerges in a deadlier form.
Iseman, Michael D. September 9, 1993. Treatment of multidrug-resistant tuberculosis. New England Journal of
Medicine, vol. 329. Tuberculosis is on the rise in a very hard-to-treat form.
Kollef, M.H., and D.P. Schuster. January 5, 1995. Medical progress: The acute respiratory distress syndrome. New
England Journal of Medicine, vol. 332. Damage to the blood supply to the lungs destroys alveoli, impairing
respiration.
Lewis, Ricki. June 1992. Defeating adult sleep apnea. FDA Consumer. In sleep apnea, a person ceases to breathe for
10 to 20 seconds hundreds of times a night. The sufferer may be aware only of fatigue; his or her bedmate hears
the snoring.
Lewis, Ricki. December 1992. Prescriptions to help smokers quit. FDA Consumer. The nicotine patch can help some
smokers quit-but it isn’t easy.
Lewis, Ricki. June 1993. Cystic fibrosis: Test, treatments improve survival. FDA Consumer. Several new treatments,
including gene therapy, are easing breathing for people with cystic fibrosis.
Poets, C.F., and D.P. Southall. August 5, 1993. Prone sleeping position and sudden infant death. New England
Journal of Medicine, vol. 329. Sleeping position may alter the risk of sudden infant death syndrome.
Williams, Rebecca D. April 1992. Preterm babies get a double breath of life. FDA Consumer. Before synthetic
surfactant became available a few years ago, premature babies routinely died because their lungs could not inflate
sufficiently.
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