Unit 5 - Respiratory System Flashcards
Which is NOT considered to be a primary function of the respiratory system? A) regulation of water balance B) regulation of pH balance C) protection against pathogens D) vocalization E) gas exchange
A) regulation of water balance
Ventilation is also known as A) breathing. B) inspiration. C) expiration. D) air conduction. E) blowing.
A) breathing.
The upper respiratory tract includes all EXCEPT which of the following? A) nasal cavity B) lungs C) trachea D) larynx E) mouth
B) lungs
The lower respiratory tract includes
A) all of the bronchial branches.
B) only the lungs.
C) only the trachea.
D) all of the bronchial branches and the lungs
E) all of the bronchial branches, the lungs, and the trachea.
D) all of the bronchial branches and the lungs
Pulmonary ventilation refers to the
A) movement of air into and out of the lungs.
B) movement of dissolved gases from the alveoli to the blood.
C) movement of dissolved gases from the blood to the interstitial space.
D) movement of dissolved gases from the interstitial space to the cells.
E) utilization of oxygen.
A) movement of air into and out of the lungs.
Alveolar ventilation refers to the
A) movement of air into and out of the lungs.
B) movement of air into and out of the alveoli.
C) movement of dissolved gases from the alveoli to the blood.
D) movement of dissolved gases from the blood to the alveoli.
E) utilization of oxygen by alveolar cells to support metabolism.
B) movement of air into and out of the alveoli.
The actual sites of gas exchange within the lungs are A) bronchioles. B) alveolar ducts. C) pleural spaces. D) alveoli. E) terminal sacs.
D) alveoli.
Place the following structures of the respiratory tree in the order in which air passes through them. 1. secondary bronchi 2. bronchioles 3. primary bronchi 4. alveoli 5. terminal bronchioles A) 4, 1, 2, 3, 5 B) 1, 3, 5, 2, 4 C) 3, 1, 5, 2, 4 D) 3, 1, 2, 5, 4 E) 1, 3, 2, 5, 4
D) 3, 1, 2, 5, 4
The airway between the larynx and the primary bronchi is the A) pharynx. B) bronchiole. C) trachea. D) alveolar duct. E) laryngeal duct.
C) trachea.
The lungs are enclosed in \_\_\_\_\_\_\_\_ membranes. A) pericardial B) pulmonary C) pleural D) thoracic E) costal
C) pleural
The lungs are located in the \_\_\_\_\_\_\_\_ cavity. A) pericardial B) pulmonary C) pleural D) thoracic E) costal
D) thoracic
Pressure and volume of gas in a container are related to temperature and number of gas molecules. This is known as \_\_\_\_\_\_\_\_ law. A) the ideal gas B) Boyle's C) Dalton's D) Henry's E) Ohm's
A) the ideal gas
Type II alveolar cells
A) allow rapid diffusion of gases through their thin membranes.
B) secrete a chemical known as surfactant.
C) are phagocytic.
D) allow rapid diffusion of gases through their thin membranes, secrete a chemical known as surfactant, and are phagocytic.
E) None of the statements are true.
B) secrete a chemical known as surfactant.
Type I alveolar cells
A) allow rapid diffusion of gases through their thin membranes.
B) secrete a chemical known as surfactant.
C) are phagocytic.
D) allow rapid diffusion of gases through their thin membranes, secrete a chemical known as surfactant, and are phagocytic.
E) None of the statements are true.
A) allow rapid diffusion of gases through their thin membranes.
Which of the following features of the alveolar sacs allows for the ease of diffusion of gasses?
A) They are made of a single layer of simple squamous epithelium.
B) Type II alveolar cells secrete surfactant.
C) Elastin fibers allow the alveoli to stretch thin enough for diffusion to occur.
D) They are made of a single layer of simple squamous epithelium and elastin fibers allow the alveoli to stretch thin enough for diffusion to occur.
A) They are made of a single layer of simple squamous epithelium.
Surfactant
A) protects the surface of the lungs.
B) phagocytizes small particulate matter.
C) replaces mucus in the alveoli.
D) helps prevent the alveoli from collapsing.
E) is not found in healthy lung tissue.
D) helps prevent the alveoli from collapsing.
The common passageway shared by the respiratory and digestive systems is the A) larynx. B) glottis. C) vestibule. D) pharynx. E) esophagus.
D) pharynx.
When the diaphragm and external intercostal muscles contract, A) the volume of the thorax increases. B) the volume of the thorax decreases. C) the volume of the lungs decreases. D) the lungs collapse. E) expiration occurs.
A) the volume of the thorax increases.
Dalton’s law states that
A) gas volume and temperature are directly proportional.
B) gas volume and pressure are inversely proportional.
C) the volume of gas that will dissolve in a solvent is proportional to the solubility of the gas and the gas pressure.
D) in a mixture of gases like air, the total pressure is the sum of the individual partial pressures of the gases in the mixture.
E) None of the answers are correct.
D) in a mixture of gases like air, the total pressure is the sum of the individual partial pressures of the gases in the mixture.
Air moves into the lungs because
A) the gas pressure in the lungs is less than outside pressure.
B) the volume of the lungs decreases with inspiration.
C) the thorax is muscular.
D) contraction of the diaphragm decreases the volume of the pleural cavity.
E) All of the answers are correct.
A) the gas pressure in the lungs is less than outside pressure.
Air moves out of the lungs because
A) the gas pressure in the lungs is less than outside pressure.
B) the volume of the lungs decreases with expiration.
C) the thorax is muscular.
D) contraction of the diaphragm increases the volume of the pleural cavity.
E) All of the answers are correct.
B) the volume of the lungs decreases with expiration.
In quiet breathing,
A) inspiration and expiration involve muscular contractions.
B) inspiration is passive and expiration involves muscular contractions.
C) inspiration involves muscular contractions and expiration is passive.
D) inspiration and expiration are both passive processes.
E) None of the answers are correct.
C) inspiration involves muscular contractions and expiration is passive.
Boyle's law states that gas volume is A) directly proportional to pressure. B) directly proportional to temperature. C) inversely proportional to pressure. D) inversely proportional to temperature. E) None of the answers are correct.
C) inversely proportional to pressure.
Air entering the body is filtered, warmed, and humidified by the A) upper respiratory tract. B) lower respiratory tract. C) lungs. D) alveoli. E) All of the answers are correct.
A) upper respiratory tract.
A typical value for intrapleural pressure is \_\_\_\_\_\_\_\_ mm Hg. A) +6 B) +3 C) 0 D) -3 E) -6
D) -3
According to the law of LaPlace, when comparing two alveoli lined with fluid, pressure in the one with the ________ diameter will be greater.
A) larger
B) smaller
B) smaller
When alveolar pressure is equal to atmospheric pressure, air flows into the lungs.
A) True
B) False
B) False
Active expiration is produced by contraction of
A) abdominal muscles only.
B) diaphragm only.
C) internal intercostals only.
D) external intercostals only.
E) abdominal muscles and internal intercostals.
E) abdominal muscles and internal intercostals.
When the diaphragm and external intercostal muscles contract, A) expiration occurs. B) intrapulmonary pressure increases. C) intrapleural pressure decreases. D) the volume of the lungs decreases. E) All of the answers are correct.
C) intrapleural pressure decreases.
If a student inhales as deeply as possible and then blows the air out until he cannot exhale any more, the amount of air that he expelled is his A) tidal volume. B) inspiratory reserve volume. C) expiratory reserve volume. D) minimal volume. E) vital capacity.
E) vital capacity.
Total cross-sectional area ________ with each division of the airways.
A) increases
B) decreases
C) does not change
A) increases
Blood vessels cover approximately \_\_\_\_\_\_\_\_% of the alveolar surface. A) 80-90 B) 10-20 C) > 90 D) < 10 E) 50
A) 80-90
In the lungs, the
A) blood flow rate is higher and the blood pressure is lower, respectively, than the blood flow rate and the blood pressure in other tissues.
B) blood flow rate is higher and the blood pressure is higher, respectively, than the blood flow rate and the blood pressure in other tissues.
C) blood flow rate is lower and the blood pressure is lower, respectively, than the blood flow rate and the blood pressure in other tissues.
D) blood flow rate is lower and the blood pressure is higher, respectively, than the blood flow rate and the blood pressure in other tissues.
E) blood flow rate and the blood pressure are the same as in other tissues.
A) blood flow rate is higher and the blood pressure is lower, respectively, than the blood flow rate and the blood pressure in other tissues.
The distance between the alveolar airspace and capillary endothelium is ________, allowing gases to diffuse ________ between them.
A) short, rapidly
B) long, rapidly
C) short, slowly
D) long, slowly
E) None of the answers are correct–distance does not affect diffusion rate.
A) short, rapidly
Flow of air
A) is directly proportional to a pressure gradient, and flow decreases as the resistance of the system increases.
B) is directly proportional to the resistance, and flow decreases as the pressure of the system increases.
C) is directly proportional to a pressure gradient, and flow increases as the resistance of the system increases.
D) is directly proportional to the resistance, and flow increases as the resistance of the system increases.
E) None of the answers are correct.
A) is directly proportional to a pressure gradient, and flow decreases as the resistance of the system increases.
An increase in PCO2 would cause
A) the bronchioles to dilate and the systemic arterioles to dilate.
B) the bronchioles to dilate and the systemic arterioles to constrict.
C) the bronchioles to constrict and the systemic arterioles to dilate.
D) the bronchioles to constrict and the systemic arterioles to constrict.
E) None of the answers are correct.
A) the bronchioles to dilate and the systemic arterioles to dilate.
Chronic inhalation of fine particles that reach the alveoli leads to \_\_\_\_\_\_\_\_ lung disease. A) obstructive B) restrictive C) fibrotic D) compliant E) congestive
C) fibrotic
Poiseuille's law is summarized this way: A) PV = nRT B) R Lη/r4 C) P = 2T/r D) P1V1 = P2V2
B) R Lη/r4
Histamine's primary role in the respiratory system is as a A) surfactant. B) bronchodilator. C) bronchoconstrictor. D) vasodilator. E) vasoconstrictor.
C) bronchoconstrictor.
the additional air inhaled after a normal inspiration
inspiratory reserve volume
the minimum amount of air always present in the respiratory system, after blowing out all you can
residual volume
the extra amount actively (forcibly) exhaled after a normal exhalation
expiratory reserve volume
the amount of air taken in during a single normal inspiration
tidal volume
the amount of air remaining in the lungs after a normal breath
functional residual capacity
the sum of all the lung volumes
total lung capacity
the amount of air inhaled during an active (forced) inspiration
inspiratory capacity
the total amount of air that can be exchanged at will
vital capacity
The beating of the cilia of the respiratory passages in the direction of the pharynx forms a ________.
mucociliary escalator
When the inspiratory muscles relax, the rib cage returns to its original position as a result of ________.
elastic recoil
The ease with which the lungs stretch in response to changes in pressure is termed ________.
compliance
The ability of a lung to recoil, or recover from stretch, is called ________.
elastance
In the disease ________, many symptoms are due to destruction of elastic fibers in the lung.
emphysema
Some have a congenital alpha-1 antitrypsin deficiency. If the job of alpha-1 antitrypsin is to inhibit trypsin and elastase, what condition are people with this genetic deficiency likely to develop?
emphysema
The substance produced by the lungs to reduce surface tension is called ________.
surfactant
The cells of the lung that produce the substance that lowers surface tension are ________
type II alveolar cells
Because of their smooth muscle component, the structures of the lower respiratory system that can most alter airway resistance are the ________.
bronchioles
A powerful bronchoconstrictor released by mast cells is ________.
histamine
Ongoing diseases in which air flow during expiration is diminished are known as ________.
chronic obstructive pulmonary diseases (COPDs)
An increase in the rate and depth of breathing is known as ________.
hyperventilation
The volume of air moved in a single respiration is called the ________.
tidal volume
The volume of air that can be forcefully expelled from the lungs following a normal exhalation is called the ________.
expiratory reserve volume
The volume of air that can be forcefully inhaled on top of a normal inspiration is called the ________.
inspiratory reserve volume
The volume of air that remains in the lungs after a forced expiration is called the ________.
residual volume
A typical residual volume (in milliliters) for a healthy, 70 kg male is ________.
1200 mL
The opposing layers of pleural membrane are held together by a thin film of ________.
pleural fluid
The larynx contains the ________, connective tissue bands that tighten and vibrate to create sound when air moves past them.
vocal cords
The primary function of the alveoli is ________.
the exchange of gases between themselves and the blood
A ________ is an instrument that measures the volume of air moved with each breath.
spirometer
Air flows into lungs because of ________ created by ________.
pressure gradients, pumps
List the muscles of inspiration and expiration.
Inspiration: diaphragm, external intercostals, scalenes, and sternocleidomastoids.
Expiration: internal intercostals, abdominal wall muscles.
Explain how the upper airways and bronchi condition the air, and why this conditioning is important.
Air is warmed to body temperature to protect alveoli and avoid disrupting body temperature, air is humidified so that the exchange epithelium will not dehydrate, and foreign material is filtered out so it will not reach the alveoli.
During normal expiration,
A) elastic recoil of stretched muscles helps return the thorax to its resting volume.
B) the internal intercostal muscles are required.
C) the abdominal muscles become involved.
D) elastic recoil of stretched muscles helps return the thorax to its resting volume and the internal intercostal muscles are required.
E) elastic recoil of stretched muscles helps return the thorax to its resting volume, the internal intercostal muscles are required, and the abdominal muscles become involved.
A) elastic recoil of stretched muscles helps return the thorax to its resting volume.
Damage to the type II cells of the lungs would contribute to
A) a thickening of the respiratory membrane.
B) an increased rate of gas exchange.
C) alveolar rupture.
D) alveolar collapse.
E) decreased surface tension in the water lining the alveoli.
D) alveolar collapse.
Harry suffers from cystic fibrosis and frequently has periods where he can hardly breathe. The problem is the result of
A) inflammation of the bronchi.
B) constriction of the trachea.
C) thick secretions that exceed the ability of the mucus elevator to transport them.
D) laryngospasms that occur in response to a toxic substance produced by the epithelial cells.
E) collapse of one or both lungs.
C) thick secretions that exceed the ability of the mucus elevator to transport them.
Breathing that involves active inspiratory and expiratory movements is called A) eupnea. B) hyperpnea. C) diaphragmatic breathing. D) costal breathing. E) shallow breathing.
B) hyperpnea.
The respiratory rate times the tidal volume corrected for dead space is the A) vital capacity. B) respiratory minute volume. C) pulmonary ventilation rate. D) alveolar ventilation rate. E) external respiration rate.
D) alveolar ventilation rate.
Increasing the alveolar ventilation rate will
A) increase the partial pressure of oxygen in the alveoli.
B) decrease the rate of oxygen diffusion from the alveoli to the blood.
C) increase the partial pressure of carbon dioxide in the alveoli.
D) decrease the rate of carbon dioxide diffusion from the blood to the alveoli.
E) have no effect on either the partial pressure or diffusion rate of gases.
A) increase the partial pressure of oxygen in the alveoli.
In the lungs, an example of the body’s reserve capacity is that
A) some areas of the lung can be closed off during rest and opened again when needed during exercise.
B) capillary beds in the lungs are reversibly collapsible, allowing blood to be shunted to additional areas during exercise.
C) pulmonary blood flow is completely under the control of the autonomic nervous system, dilating arteries and arterioles to adjust blood flow.
D) All of the statements are true.
E) None of the statements are true.
B) capillary beds in the lungs are reversibly collapsible, allowing blood to be shunted to additional areas during exercise.
Joe is playing in an intramural football game when he is tackled so hard that he breaks a rib. He can actually feel a piece of the rib sticking through the skin, and he is having a difficult time breathing. Joe probably is suffering from A) a collapsed trachea. B) an obstruction in the bronchi. C) a pneumothorax. D) decreased surfactant production. E) a bruised diaphragm.
C) a pneumothorax.
In a condition known as pleurisy, there is excess fluid in the pleural space. How would you expect this to affect the process of pulmonary ventilation?
A) Ventilation would require less energy.
B) Breathing would be labored and difficult.
C) It would be easier to expand the lungs on inspiration.
D) More air would be forced out during expiration.
E) Tidal volume would increase.
B) Breathing would be labored and difficult.
cessation of breathing
apnea
increased respiratory rate and/or volume without increased metabolism
hyperventilation
increased respiratory rate and/or volume due to increased metabolism
hyperpnea
rapid breathing
tachypnea
difficulty breathing
dyspnea
Match the change in gas composition with the response (disregard weak responses).
A. PO2 increases. B. PCO2 increases. C. PO2 decreases. D. PCO2 decreases.
Arterioles: systemic constrict, pulmonary dilate.
A. PO2 increases.
Match the change in gas composition with the response (disregard weak responses).
A. PO2 increases. B. PCO2 increases. C. PO2 decreases. D. PCO2 decreases.
Bronchioles and systemic arterioles dilate.
B. PCO2 increases.
Match the change in gas composition with the response (disregard weak responses).
A. PO2 increases. B. PCO2 increases. C. PO2 decreases. D. PCO2 decreases.
Arterioles: systemic dilate, pulmonary constrict.
C. PO2 decreases.
Match the change in gas composition with the response (disregard weak responses).
A. PO2 increases. B. PCO2 increases. C. PO2 decreases. D. PCO2 decreases.
Bronchioles and systemic arterioles constrict.
D. PCO2 decreases.
Which single muscle contributes most to normal, resting inspiration? Which single muscle contributes most to normal, resting expiration?
The diaphragm muscle provides most of the force for inspiration. Normal expiration is primarily a result of the diaphragm relaxing, and expiratory muscles do not contribute.
Distinguish between cellular and external respiration.
Cellular respiration refers to the intracellular reactions that consume oxygen and produce ATP. External respiration refers to the exchange of gases between the environment and the lungs, lungs and blood, blood and cells, and the transport of those gases.
Describe the pleura and explain its role in respiration.
The pleura is a double-walled sac that surrounds each lung. One wall clings to the lung surface, the other to the wall of the thoracic cavity. The pleura secretes and contains pleural fluid, which is a lubricant. Pleural fluid also keeps the wall of the lung in close proximity to the wall of the thoracic cavity, which is critical in the process of pulmonary ventilation.
Distinguish between intrapulmonary and intrapleural pressure.
Intrapulmonary pressure is the pressure inside the alveoli. Intrapleural pressure is the pressure within the pleural cavity. Intrapleural pressure variation drives variation inside the alveoli, but is always lower than atmospheric pressure, where pressure inside the alveoli equilibrates with atmospheric pressure during the respiratory cycle.
What is surfactant? Why is it important?
Surfactant, made by the type II alveolar cells, reduces the surface tension in the fluid in the alveoli, thereby facilitating inflation and inhibiting collapse of the alveoli.
Julia is breathing 14 times per minute, with a tidal volume of 520 mL and a dead space of 152 mL. Lyle is breathing 15 times per minute, with a tidal volume of 400 mL and a dead space of 175 mL. Which patient has better alveolar ventilation?
Alveolar ventilation = ventilation rate × (tidal volume - dead space volume). Julia’s ventilation is 5432 mL/min, which is better than Lyle’s, which is 3375 mL/min.
Cindy is taking 14 breaths per minute. Her vital capacity is 3000 mL, her total lung capacity is 4000 mL, and her tidal volume is 450 mL per breath. Calculate the following:
A. Cindy’s total pulmonary ventilation (minute volume)
B. Cindy’s alveolar ventilation rate
A. 14 breaths/min × 450 mL/breath = 6300 mL/min
B. Alveolar vent = 14 breaths/min × (450 mL/ breath - 150 mL dead space)
= 14 breaths/min × 300 mL/breath = 4200 mL/min
High carbon dioxide concentration in body fluids is called A) carbonation. B) hyperdioxia. C) hyperoxia. D) hypercarbia. E) hypercapnia.
E) hypercapnia.
The partial pressure of oxygen in arterial blood is approximately \_\_\_\_\_\_\_\_ mm Hg. A) 40 B) 45 C) 50 D) 70 E) 100
E) 100
The partial pressure of carbon dioxide in the cells of peripheral tissues is approximately \_\_\_\_\_\_\_\_ mm Hg. A) 40 B) 45 C) 50 D) 70 E) 100
B) 45
Of the factors that influence diffusion of respiratory gases, the most variable and, therefore, important factor to consider is the A) concentration gradient. B) diffusion distance. C) membrane surface area. D) membrane thickness. E) electrical charge.
A) concentration gradient.
The process by which dissolved gases are exchanged between the blood and interstitial fluids is A) pulmonary ventilation. B) external respiration. C) diffusion. D) cellular respiration. E) breathing.
C) diffusion.
The lung pathology most likely to result from certain kinds of heart disease is A) emphysema. B) asthma. C) pulmonary edema. D) fibrotic lung disease. E) lung cancer.
C) pulmonary edema.
Hypoxia resulting from fluid accumulation in the alveoli that cannot be corrected by oxygen therapy can lead to A) emphysema. B) fibrotic lung disease. C) asthma. D) adult respiratory distress syndrome. E) sudden infant death syndrome.
D) adult respiratory distress syndrome.
If the partial pressure of oxygen in both air and water is 100 mm Hg, then the concentration of the oxygen is the same in the air and water.
A) True
B) False
B) False
The variables of oxygen consumption, cardiac output, and blood oxygen content are unrelated.
A) True
B) False
B) False
Which of the following characteristics makes hemoglobin’s structure such a good match for its function as an oxygen carrier?
A) Each hemoglobin molecule can bind one oxygen molecule.
B) Each hemoglobin molecule can bind two oxygen molecules.
C) Each hemoglobin molecule can bind four oxygen molecules.
D) Each hemoglobin molecule can’t be saturated by oxygen molecules.
E) Each hemoglobin binds irreversibly to an oxygen molecule.
C) Each hemoglobin molecule can bind four oxygen molecules.
Most of the oxygen transported by the blood is
A) dissolved in plasma.
B) bound to hemoglobin.
C) in ionic form as solute in the plasma.
D) bound to a plasma protein.
E) carried by white blood cells.
B) bound to hemoglobin.
At a PO2 of 70 mm Hg and normal temperature and pH, hemoglobin is \_\_\_\_\_\_\_\_% saturated with oxygen. A) 10 B) 25 C) 50 D) 75 E) over 90
E) over 90
Which of the following would make the oxygen-hemoglobin curve shift right? A) increased H+ concentration B) increased pH C) decreased temperature D) decreased CO2 E) None of the answers are correct.
A) increased H+ concentration
Chronic hypoxia
A) increases 2,3-DPG production in blood.
B) shifts the HbO2 dissociation curve to the left.
C) can be caused by anemia.
D) increases 2,3-DPG production in blood and can result from anemia.
E) All of the answers are correct.
D) increases 2,3-DPG production in blood and can result from anemia.
Most of the carbon dioxide in the blood is transported as
A) solute dissolved in the plasma.
B) carbaminohemoglobin.
C) bicarbonate ions.
D) solute dissolved in the cytoplasm of red blood cells.
E) carbonic acid.
C) bicarbonate ions.
In the medulla oblongata, the nucleus tractus solitarius contains the \_\_\_\_\_\_\_\_ of neurons. A) pontine respiratory group B) ventral respiratory group C) dorsal respiratory group D) pre-Botzinger complex
C) dorsal respiratory group
The most important chemical regulator of respiration is A) oxygen. B) carbon dioxide. C) bicarbonate ion. D) sodium ion. E) hemoglobin.
B) carbon dioxide.
An increase in the level of carbon dioxide in the blood will
A) decrease the rate of breathing.
B) increase the rate of breathing.
C) decrease pulmonary ventilation.
D) decrease the alveolar ventilation rate.
E) increase the pH of arterial blood.
B) increase the rate of breathing.
The expiratory neurons control the ________ muscles, whereas the inspiratory neurons control the ________ muscles.
A) diaphragm and external intercostal, abdominal and internal intercostal
B) abdominal and internal intercostal, diaphragm and external intercostal
C) diaphragm and internal intercostal, abdominal and external intercostal
D) abdominal and external intercostal, diaphragm and internal intercostal
E) diaphragm and abdominal, intercostal internal and external
B) abdominal and internal intercostal, diaphragm and external intercostal
If the neural connections between the pons and medulla are severed, breathing will stop.
A) True
B) False
B) False
The Hering-Breuer reflex
A) functions to increase ventilation with changes in blood pressure.
B) alters pulmonary ventilation when the PO2 changes.
C) alters pulmonary ventilation when the PCO2 changes.
D) prevents overexpansion of the lungs.
E) is an important aspect of normal, quiet breathing.
D) prevents overexpansion of the lungs.
Protective reflexes of the lungs include A) coughing. B) bronchoconstriction. C) bronchodilation. D) bronchodilation and coughing. E) coughing and bronchoconstriction.
E) coughing and bronchoconstriction.
destruction of alveoli
emphysema
thickened alveolar membrane and decreased lung compliance
fibrotic lung disease
decreased surface area for gas exchange
emphysema
increased airway resistance
asthma
fluid accumulation in interstitial spaces
pulmonary edema
increased diffusion distance
pulmonary edema
Match the factor with its effect on the affinity of hemoglobin for oxygen.
increased temperature
decrease
Match the factor with its effect on the affinity of hemoglobin for oxygen.
increased pH
increase
Match the factor with its effect on the affinity of hemoglobin for oxygen.
increased PCO2
decrease
Match the factor with its effect on the affinity of hemoglobin for oxygen.
increased 2,3-DPG
decrease
Generally, PO2 in arterial blood is ________ than PO2 in venous blood.
higher
Generally, PCO2 in arterial blood is ________ than PCO2 in venous blood.
lower
PCO2 tends to be ________ in tissues than in systemic capillaries.
higher
Diffusion rate is directly proportional to ________ and ________.
surface area, concentration gradient
________ is characterized by a decreased surface area for gas exchange in the lungs.
Emphysema
________ is characterized by a thickened alveolar membrane, slowing respiratory gas exchange.
Fibrotic lung disease
In ________, fluid accumulates in the interstitial spaces of the lungs, slowing gas exchange.
pulmonary edema
________ is characterized by an increased airway resistance and decreased ventilation.
Asthma
Diffusion rate is indirectly proportional to ________.
membrane thickness
The ________ group of neurons contains mostly inspiratory neurons. The ________ group of neurons controls muscles used for active expiration and some inspiratory muscles.
dorsal respiratory; ventral respiratory
The output of the ________ group of inspiratory neurons controls the ________ muscle(s) by way of the ________ nerve.
dorsal respiratory, diaphragm (or internal intercostal), phrenic (or intercostal)
Inappropriate relaxation of the ________ muscles during sleep contributes to ________, a sleep disorder associated with snoring.
mouth and throat (larynx, pharynx, and tongue), obstructive sleep apnea
Specialized ________ in the carotid and aortic bodies are activated by a decrease in PO2 and pH or an increase in PCO2. What do they trigger?
glomus cells; they trigger a reflex increase in ventilation.
The carotid and aortic bodies contain specialized ________ cells, which can increase ventilation in response to changes in PO2, PCO2, or pH.
glomus
Fear and excitement may affect the pace and depth of respiration by stimulation of portions of the ________.
limbic system
What are the three ways CO2 is transported in blood? Approximately what percentage is transported by each way?
- attached to hemoglobin, 23%
- dissolved, 7%
- as bicarbonate, 70%
Jill lives in St. Louis, which is close to sea level. She decides to spend a month of her summer vacation working in the mountains outside of Denver. After a week in the mountains, what kinds of changes would you expect to see as Jill adapts to the higher altitude? A) decreased hematocrit B) decreased blood pressure C) decreased alveolar ventilation rate D) decreased PO2 in the alveoli E) All of the answers are correct.
D) decreased PO2 in the alveoli
Carbon dioxide is more soluble in water than oxygen. To get the same amount of oxygen to dissolve in plasma as carbon dioxide, you would have to
A) decrease the temperature of the plasma.
B) increase the partial pressure of oxygen.
C) decrease the partial pressure of nitrogen.
D) increase the rate of plasma flow through the lungs.
E) decrease the alveolar ventilation rate.
B) increase the partial pressure of oxygen.
For maximum efficiency in loading oxygen at the lungs,
A) the pH should be slightly acidic.
B) the temperature should be slightly lower than normal body temperature.
C) the PO2 should be about 70 mm.
D) DPG levels in the red blood cells should be high.
E) All of the answers are correct.
B) the temperature should be slightly lower than normal body temperature.
A student in your lab volunteers to enter a hypoxic breathing chamber for 10 minutes, and his alveolar PO2 drops to 50 mm Hg. What other change would occur? A) decrease in arterial pH B) decrease in arterial PCO2 C) decrease in pH of cerebrospinal fluid D) increase in alveolar PCO2 E) hypoventilation
B) decrease in arterial PCO2
A molecule that blocks the activity of carbonic anhydrase would
A) interfere with oxygen binding to hemoglobin.
B) cause an increase in blood pH.
C) increase the amount of bicarbonate formed in the blood.
D) decrease the amount of carbon dioxide dissolved in the plasma.
E) All of the answers are correct.
B) cause an increase in blood pH.
The chloride shift occurs when
A) hydrogen ions leave the red blood cells.
B) hydrogen ions enter the red blood cells.
C) bicarbonate ions enter the red blood cells.
D) bicarbonate ions leave the red blood cells.
E) carbonic acid is formed.
D) bicarbonate ions leave the red blood cells.
Blocking afferent action potentials from the chemoreceptors in the carotid and aortic bodies would interfere with the brain’s ability to regulate breathing in response to all EXCEPT which of the following?
A) changes in PCO2
B) changes in PO2
C) changes in pH due to carbon dioxide levels
D) changes in blood pressure
E) All of the answers are correct.
D) changes in blood pressure
What are the two possible causes of lower alveolar PO2? Give examples of each.
- The composition of the inspired air is abnormal. Altitude affects oxygen content of air.
- Alveolar ventilation is inadequate. Pathological factors include increased airway resistance (asthma), decreased lung compliance (fibrosis), and overdoses of drugs or alcohol.
Describe the problems that result in low arterial oxygen content.
Three categories of problems are inadequacies in oxygen reaching alveoli, oxygen exchange between the alveoli and blood, and transport of oxygen in the blood.
Explain how oxygen and carbon dioxide are transported in the blood. How does the means of transport relate to the solubility and chemical reactivity of these gases in plasma?
Oxygen is not highly soluble in water, which is the main component of plasma. Less than 2% is dissolved in plasma, with the remainder bound to hemoglobin. The iron in the heme portion of the molecule can bind up to four oxygen atoms. Oxygen is not chemically reactive in the body. Carbon dioxide is more soluble than oxygen, at about 7% dissolved. Carbon dioxide is chemically reactive, combining with water to form carbonic acid, which then dissociates to bicarbonate and hydrogen ion. Most carbon dioxide is transported in the form of bicarbonate, about 70%, and the remaining 23% binds to amino acids on hemoglobin.
List, compare, and contrast the brain’s centers for monitoring and controlling respiration.
Respiratory neurons in the medulla control inspiration and expiration. Neurons in the pons modulate ventilation. The rhythmic pattern of breathing arises from a network of spontaneously discharging neurons. Ventilation is subject to modulation by various chemical factors and by higher brain centers.
List, compare, and contrast the locations and stimuli for respiratory chemoreceptors.
Peripheral chemoreceptors in the carotid and aortic bodies sense changes in oxygen concentration, pH, and PCO2 of the plasma. Central chemoreceptors monitor cerebrospinal fluid composition and respond to changes in the concentration of CO2 in the cerebrospinal fluid.
Which is typically more important in regulating the respiratory system, PO2 or PCO2? Explain your answer and briefly discuss the receptors involved. Give examples of situations in which each of those factors changes enough to stimulate a reflex. How and why are these factors related to each other?
PCO2 is the more important factor. For PCO2, there are central and peripheral receptors that respond to CO2 as well as to CO2-related pH. These receptors are very sensitive to routine changes in PCO2 and pH, such as those associated with an increase in physical activity. Peripheral chemoreceptors have been identified for O2, but these respond only to dramatic changes in PO2, such as those associated with high altitude or disease. Because CO2 is produced as a by-product of aerobic (oxygen-consuming) metabolism, an increase in CO2 is associated with a corresponding decrease in O2.
