Chapter 22

25 July 2022
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question
In pneumothorax, the lung collapses because ______.
answer
intrapleural pressure is equal to intrapulmonary pressure. Intrapleural pressure (Ppul) is the gas pressure within the pleural cavity, while intrapulmonary pressure (Pip) is the gas pressure within the alveoli. Normally Ppul is less than Pip to maintain lung expansion. If Ppul exceeds Pip, then the lungs collapse.
question
If the compliance of the thoracic wall is decreased, ______. - the intrapleural pressure would not decrease normally during inhalation - the intrapulmonary pressure would remain lower than the atmospheric pressure - the airway resistance would be decreased - None of the listed responses is correct.
answer
the intrapleural pressure would not decrease normally during inhalation. As the size of the thoracic cavity increases, so does its volume. This causes intrapleural pressure to go below atmospheric pressure so that air (gases) can move into the lungs during inspiration. If the thoracic cavity cannot change its size (volume), then intrapleural pressure will not decrease and normal air movement will not occur.
question
Hypocapnia causes ______. - the level of bicarbonate ions in the blood to rise - hypoxia - an increase in VRG activity - hyperventilation
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hypoxia. Hypoxia occurs when too little oxygen is delivered to the tissues. Low carbon dioxide levels stimulate chemoreceptors in the brain and great vessels that signal the respiratory centers of the brain to slow down the respiratory rate. As rate falls, so does the rate of external respiration leading to lower oxygen saturation.
question
Patients with rhinitis often have "watery eyes" because ______. - the infection has stimulated increased lacrimal fluid secretion by the lacrimal glands - the infection has caused inflammation of the nasolacrimal ducts - the paranasal sinuses are blocked with excess mucus - All of the listed responses are correct.
answer
the infection has caused inflammation of the nasolacrimal ducts.
question
The adenoids normally destroy pathogens because they contain ______. - white pulp that performs immune functions - red pulp that performs immune functions - lymph nodes - lymphocytes
answer
lymphocytes The adenoids (pharyngeal tonsils), which are located in the posterior wall of the pharynx posterior to the soft palate, are part of a ring of lymphatic tissue surrounding the entrance to the laryngopharynx. They function to trap inhaled bacteria and facilitate activation of resident lymphocytes.
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The tissue(s) and/or cells that may be affected during laryngitis ______. - is epithelial tissue - is a mucous membrane - are ciliated cells - All of the listed responses are correct.
answer
All of the listed responses are correct.
question
Smoking inhibits cilia by inhibiting the movements of ______. - dynein molecules - the basal bodies - microvilli - actin filaments
answer
dynein molecules. Dynein is a motor protein that moves cilia causing them to bend. Collectively cilia propel other substances (like mucus) across the cell's surface.
question
Which of the following helps to protect against tracheal obstruction. - carina of the trachea - trachealis muscle - larynx - tracheal cartilage
answer
larynx. The larynx is superior to the trachea in the respiratory tract. The laryngeal opening (glottis) is covered by the epiglottis during swallowing, normally preventing ingested materials from passing into the trachea.
question
During pleurisy, the inflamed parietal pleura of one lung rubs against the inflamed ______. - thoracic wall - parietal pleura of the other lung - visceral pleura of the same lung - visceral pleura of the other lung
answer
visceral pleura of the same lung. Normally the visceral and parietal pleura of one lung glide easily over one another during breathing because they are smooth and lubricated by pleural fluid. During pleurisy, they become rough and friction develops between the two layers.
question
Which of the following could be involved in causing bronchiolar constriction during an asthma attack? - acetylcholine - central nervous system - peripheral nervous system - release of histamine and inflammatory chemicals in the airway walls
answer
release of histamine and inflammatory chemicals in the airway walls. Acute asthma attacks are usually associated with an allergen-induced local release of histamine and other inflammatory chemicals in the airways.
question
In babies born prematurely, pulmonary surfactant may not be present in adequate amounts ______. - in the conducting zone structures of the lungs - due to insufficient exocytosis in the type II alveolar cells - to permit adequate surface tension in the alveoli - because the presence of collapsed alveoli prevents surfactant production
answer
due to insufficient exocytosis in the type II alveolar cells. Type II alveolar cells make surfactant which they release via exocytosis onto the inner wall of alveoli. Without surfactant, the surface tension created by the water vapor within the alveoli would cause them to collapse.
question
Which of the following structures would be the LEAST vulnerable to damage caused by oxygen toxicity? - brain - spleen - muscles - costal cartilages
answer
costal cartilages. Cartilage is normally avascular and receives oxygen by diffusion from surrounding capillaries.
question
During pneumonia, the lungs become "waterlogged"; this means that within the alveoli there is an abnormal accumulation of ______. - blood - blood plasma - interstitial fluid - water
answer
interstitial fluid. Pneumonia is an infection within the lung tissue often accompanied by inflammation. In response to inflammation, the increased permeability of the respiratory membrane results in increased formation of interstitial fluid that enters the alveoli.
question
Emphysema can result in an ______. increased level of carbaminohemoglobin increased level of deoxyhemoglobin increased likelihood of the skin of Caucasians developing a slightly blue coloration All of the listed responses are correct.
answer
All of the listed responses are correct.
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pneumothorax
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the presence of air or gas in the cavity between the lungs and the chest wall, causing collapse of the lung.
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hypercapnia
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excessive carbon dioxide in the blood.
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bronchioles
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smallest branches of the bronchi, measuring less than 1 mm.
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Under ordinary circumstances, which of the following blood components is of no physiological significance? chloride bicarbonate ions carbaminohemoglobin nitrogen
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nitrogen Nitrogen (N2) is poorly soluble in water. Under normal atmospheric pressures, nitrogen does not enter/leave our body fluids like oxygen (O2) and carbon dioxide (CO2). Therefore, under ordinary circumstances, nitrogen has no physiological significance in the body.
question
What area in the brain sets the respiratory rhythm?
answer
ventral respiratory group (VRG)
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Inspiratory neurons send information to the diaphragm via what nerve?
answer
Phrenic Nerve
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What directly stimulates the central chemoreceptors, thus increasing respiration? - high CO2 (carbon dioxide) - high pH - H+ (hydrogen ions) - low O2 (oxygen)
answer
H+ (hydrogen ions) hydrogen ions (H+) stimulate the central chemoreceptors. CO2 is converted to H+ in the extracellular fluid of the brain.
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As a result of hyperventilation, what will happen to the partial pressures of CO2 (pCO2) and pH? - increased pCO2 and increased pH - decreased pCO2 and decreased pH - increased pCO2 and decreased pH - decreased pCO2 and increased pH
answer
decreased pCO2 and increased pH pCO2 would decrease and pH would increase. As CO2 is blown off, H+ would decrease, thus increasing pH.
question
Which receptors inhibit inspiration during hyperinflation of the lungs? - pulmonary stretch receptors - irritant receptors - Hypothalamic receptors - peripheral chemoreceptors
answer
pulmonary stretch receptors
question
What stimulates increased respiration at the beginning of exercise? - sensory input from receptors in joints, neural input from the motor cortex, and other factors - increased plasma carbon dioxide levels - increased hydrogen ion levels - decreased plasma oxygen levels
answer
sensory input from receptors in joints, neural input from the motor cortex, and other factors
question
A homeostatic control mechanism controls respiration. What acts as the effector(s) in this system? - medulla oblongata - central chemoreceptors - respiratory muscles - peripheral chemoreceptors
answer
respiratory muscles. the respiratory muscles change the volume of the thoracic cavity (and thus the pressure), resulting in inspiration and expiration.
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Which of the following processes are unique to the respiratory system? - pulmonary ventilation and internal respiration - external and internal respiration - pulmonary ventilation and external respiration - pulmonary ventilation and transport of respiratory gases
answer
pulmonary ventilation and external respiration
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Which of the following processes is NOT properly matched with its description? - external respiration: CO2 diffuses into the blood stream - internal respiration: O2 diffuses out of the blood - pulmonary ventilation: movement of gases into and out of the lungs - transport of respiratory gases: O2 is bound to hemoglobin
answer
external respiration: CO2 diffuses into the blood stream. CO2 diffuses into the blood as it passes through the systemic capillaries of the tissues; this is internal respiration.
question
True or False: The division between the upper and lower respiratory system is at the nasopharynx.
answer
False. The separation between the upper and lower respiratory system occurs at the larynx. The upper respiratory system consists of all the structures from the nose to the larynx. The lower respiratory system consists of the larynx and all the structures below it.
question
Which of the following is NOT a benefit of breathing through the nose? - the production of smooth, laminar airflow as air passes by the nasal conchae - recovering heat and moisture from the air leaving the nasal cavity - filtration of the air entering the nasal cavity - heating and moistening the air entering the nasal cavity
answer
the production of smooth, laminar airflow as air passes by the nasal conchae. In fact, airflow becomes turbulent (not smooth or laminar) as the gases of inhaled air swirl through the twists and turns created by the curved nasal conchae protruding medially from each lateral wall of the nasal cavity. Heavier, nongaseous particles deflect onto the mucus-coated surfaces, where they become trapped. As a result, few particles larger than 6 ฮผm make it past the nasal cavity.
question
Which of the following is an organ shared by the respiratory system and the digestive system? - larynx - trachea - esophagus - pharynx
answer
pharynx. The funnel-shaped pharynx connects the nasal cavity and mouth superiorly to the larynx and esophagus inferiorly. Commonly called the throat, the pharynx is the site where our respiratory pathway, from nose to larynx, crosses the digestive pathway, from mouth to esophagus.
question
Which of these structures is/are NOT properly matched with one of its/their functions? - nasal conchae: increase the mucosal surface area exposed to air - paranasal sinuses: house olfactory receptors - nasopharynx: conduct air toward and from the larynx - pharyngeal tonsil: trap and destroy pathogens entering the nasopharynx in air
answer
paranasal sinuses: house olfactory receptors. The sinuses contain open spaces that lighten the skull and may help to warm and humidify air entering the respiratory system. The sinuses are all outside of the nasal cavity, which is where the odor receptors would be found.
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True or False: The lingual tonsil is found on the posterior surface of the root of the tongue.
answer
True
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True or False: The functions of the nasal conchae are to enhance the air turbulence in the cavity and to increase the mucosal surface area exposed to air for greater efficiency.
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True
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True or False: Nasal conchae heat and moisten inhaled air, and reclaim heat and moisture during exhalation.
answer
True
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Which bone does NOT contain paranasal sinuses? - maxillary - frontal - ethmoid - temporal
answer
temporal
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The nose serves all of the following functions EXCEPT ________. - warming and humidifying the air - as the direct initiator of the cough reflex - as a passageway for air movement - cleansing the air
answer
as the direct initiator of the cough reflex
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Most inspired particles such as dust fail to reach the lungs because of the ________. - porous structure of turbinate bones - abundant blood supply to nasal mucosa - action of the epiglottis - ciliated mucous lining in the nose
answer
ciliated mucous lining in the nose.
question
The palatine tonsils are found in which region?
answer
oropharynx
question
Which of the following is NOT a function of the nasal conchae? - reclaiming heat and moisture from expired air - increasing the mucosal surface area exposed to air - filtering, heating, and moistening incoming air during inhalation - routing air and food into proper channels
answer
routing air and food into proper channels. While the nasal conchae are used for routing air, they are not involved in routing food. The nasal conchae are coated with membrane that has a rich blood supply; this cleans, humidifies, and warms incoming air.
question
Which region contains the opening of a canal that equalizes pressure in the middle ear?
answer
nasopharynx.
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Which of the following is/are part(s) of the respiratory zone structures? - alveoli - trachea - terminal bronchioles - primary bronchi
answer
alveoli. Along with the respiratory bronchioles and alveolar ducts, the alveoli make up the respiratory zone.
question
What structure prevents food and liquids from entering the trachea?
answer
epiglottis. During swallowing, the larynx is pulled superiorly and the epiglottis tips to cover the laryngeal inlet. Because this action keeps food out of the lower respiratory passages, the epiglottis has been called the guardian of the airways.
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True or False: The alveolar ducts are part of the conducting zone.
answer
False. Respiratory system organs are divided functionally into conducting zone structures (nose to terminal bronchioles), which filter, warm, and moisten incoming air; and respiratory zone structures (respiratory bronchioles and alveolar ducts to alveoli), where gas exchanges occur.
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True or False; The Heimlich maneuver is a procedure in which air in the lungs is used to expel a piece of food lodged in the esophagus.
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False.
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True or False: Smoking diminishes ciliary action and eventually destroys the cilia.
answer
True
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True or False: Tracheal obstruction is life threatening.
answer
True
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True or False: Under certain conditions, the vocal folds act as a sphincter that prevents air passage.
answer
True
question
The loudness of a person's voice depends on the ________.
answer
force with which air rushes across the vocal folds.
question
The walls of the alveoli are composed of two types of cells, type I and type II alveolar cells. The function of type II alveolar cells is to ________.
answer
secret surfactant.
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Which of the following maintains the patency (openness) of the trachea? - surface tension of water - C-shaped cartilage rings - surfactant production - pseudostratified ciliated epithelium
answer
C-shaped cartilage rings.
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As the tension of vocal folds in the larynx increase, the voice becomes ________.
answer
higher in pitch.
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The larynx contains ________. - a cricoid cartilage also called the Adam's apple - lateral cartilage ridges called false vocal folds - the thyroid cartilage - an upper pair of avascular mucosal folds called true vocal folds
answer
the thyroid cartilage.
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Which of the following provide the greatest surface area for gas exchange? - alveolar ducts - alveoli - alveolar sacs - respiratory bronchioles
answer
alveoli.
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Which of the following is NOT part of the respiratory membrane of the lungs? - basement membrane -alveolar epithelium - capillary endothelium - single layer of smooth muscle cells
answer
single layer of smooth muscle cells.
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Which structure is lined with simple squamous epithelium? - alveolus - nasopharynx - oropharynx - trachea
answer
alveolus.
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Which of the following anchor(s) the vocal folds? - cricoid cartilage - corniculate cartilages - arytenoid cartilages - cuneiform cartilages
answer
arytenoid cartilages.
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Which of the following is a conducting zone structure? - terminal bronchiole - alveolar duct - alveolar sac - respiratory bronchiole
answer
terminal bronchiole.
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_______________: No exchange of gases occurs here Type I cells Alveolar duct Segmental bronchi Respiratory bronchioles Type II cells
answer
Segmental bronchi : No exchange of gases occurs here.
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____________ : Secrete a fluid containing surfactant. Type I cells Alveolar duct Segmental bronchi Respiratory bronchioles Type II cells
answer
Type II cells : Secrete a fluid containing surfactant.
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_____________ : Where the respiratory zone of the lungs begins. Type I cells Alveolar duct Segmental bronchi Respiratory bronchioles Type II cells
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Respiratory bronchioles : Where the respiratory zone of the lungs begins.
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_____________ : Form a simple squamous epithelium in the alveoli. Type I cells Alveolar duct Segmental bronchi Respiratory bronchioles Type II cells
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Type I cells : Form a simple squamous epithelium in the alveoli.
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____________ : Terminates in alveoli. Type I cells Alveolar duct Segmental bronchi Respiratory bronchioles Type II cells
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Alveolar duct : Terminates in alveoli.
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____________ : Are cuboidal cells. Type I cells Alveolar duct Segmental bronchi Respiratory bronchioles Type II cells
answer
Type II cells : Are cuboidal cells.
question
The respiratory membrane consists of 3 layers: capillary endothelium, fused basement membrane and alveolar epithelium consisting of ______________. Type I cells Alveolar duct Segmental bronchi Respiratory bronchioles Type II cells
answer
The respiratory membrane consists of 3 layers: capillary endothelium, fused basement membrane and alveolar epithelium consisting of Type I cells.
question
What part of the larynx covers the laryngeal inlet during swallowing to keep food out of the lower respiratory passages?
answer
epiglottis. When the larynx is elevated during the act of swallowing, the epiglottis is pressed over the glottis to prevent swallowed food from entering the lower respiratory passages.
question
Which cartilage belonging to the larynx anchors vocal cords? - thyroid cartilage - epiglottis cricoid - cartilage - arytenoid cartilage
answer
arytenoid cartilage.
question
Which of these structures forms a complete ring around the airway? - thyroid cartilage - hyoid bone - cricoid cartilage - tracheal cartilage
answer
cricoid cartilage. The cricoid cartilage makes a complete ring around the airway, stabilizing the glottis, the vocal cords, and the epiglottis.
question
Which of these cells would be most effective in the disposal of inspired microorganisms that may enter the alveoli? - type I alveolar cells - type II alveolar cells - alveolar macrophages - lymphocytes in blood circulating through the lungs
answer
alveolar macrophages. Alveolar macrophages wander freely, ingesting and destroying invading microorganisms or foreign matter.
question
What type of epithelial tissue forms the walls of the alveoli?
answer
simple squamous epithelium. Squamous epithelia are thin and easily passed through by respiratory gases. The membrane is also kept thin by organizing the squamous cells in a single layer.
question
In children with infant respiratory distress syndrome (IRDS), the walls of the alveoli cling to each other and make them difficult to inflate. It is common in babies born prematurely. What cells in these infants are NOT fully developed and are NOT doing their job? - endothelial cells of alveolar capillaries - alveolar macrophages - type I alveolar cells - type II alveolar cells
answer
type II alveolar cells. Type II alveolar cells secrete a detergent-like surfactant that lessens the surface tension on the alveolar walls, preventing them from sticking to each other. Infants with IRDS can be treated until their cells produce adequate surfactant.
question
Which of the following observations would only be found in the right lung? - a horizontal fissure - a cardiac notch - two lobes - an oblique fissure
answer
a horizontal fissure.
question
One of the following statements about pleural fluid and the pleural cavity is INCORRECT. Which one? - The intrapleural pressure is always less than the intrapulmonary pressure. - Pleural fluid is normally present in the pleural cavity. - Pleural fluid is produced by the lung alveoli. - The parietal pleura covers the superior part of the diaphragm.
answer
Pleural fluid is produced by the lung alveoli.
question
Which of the following statements about the pleurae is NOT true? - The parietal and visceral pleura are continuous. - The visceral pleura covers the external lung surface and lines the fissures between lobes. - The pleurae create one continuous cavity for both lungs. - The pleural lining reduces friction during ventilation.
answer
The pleurae create one continuous cavity for both lungs. Each lung has its own, separate pleura. The mediastinum surrounds the heart and vessels in the medial thoracic cavity.
question
True or False: The lungs are perfused by two circulations: the pulmonary and the bronchial. The pulmonary circulation is for oxygenation of blood. The bronchial circulation supplies blood to the lung structures (tissue).
answer
True
question
True or False: The paired lungs occupy the mediastinum of the thoracic cavity.
answer
False
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True or False: The parietal pleura lines the thoracic wall.
answer
True
question
The left lung differs from the right in that the left lung has ________.
answer
a cardiac notch.
question
Which of the choices below is NOT a role of the pleurae? - help limit the spread of local infections - help divide the thoracic cavity into three chambers - allow the lungs to glide easily over the thorax wall during breathing movements - assist in blood flow to and from the heart because the heart sits between the lungs
answer
assist in blood flow to and from the heart because the heart sits between the lungs.
question
Which of the following is responsible for holding the lungs to the thorax wall? - the smooth muscles of the lung - the visceral pleurae and the changing volume of the lungs - surface tension from pleural fluid and negative pressure in the pleural cavity - the diaphragm and the intercostal muscles alone
answer
surface tension from pleural fluid and negative pressure in the pleural cavity.
question
Which of the following cavities surround(s) the lungs alone? - mediastinum - pleural cavities - pericardial cavity - thoracic cavity
answer
pleural cavities.
question
Which blood vessels supply deoxygenated systemic blood to the alveoli?
answer
pulmonary arteries.
question
The indentation on the medial surface of each lung through which pulmonary and systemic blood vessels, bronchi, lymphatic vessels, and nerves enter and leave is called the __________.
answer
hilum.
question
During inhalation, __________ - the diaphragm relaxes. - oxygen molecules move into the lungs, and carbon dioxide molecules move out of the lungs. - air moves up the trachea. - the diaphragm and rib muscles contract. - the volume of the thoracic cavity decreases.
answer
the diaphragm and rib muscles contract.
question
From which structures do oxygen molecules move from the lungs to the blood? - Bronchioles - Trachea - Bronchi - Alveoli - Nose
answer
Alveoli. Alveoli are tiny sacs in the lungs surrounded by capillaries. The alveoli are where oxygen diffuses from the lungs to the blood.
question
Which statement is correct? - In the blood, oxygen is bound to hemoglobin, a protein found in red blood cells. - Oxygen diffuses from large blood vessels into the body's cells. - Carbon dioxide diffuses from the alveoli into surrounding capillaries. - As oxygen diffuses from the lungs into capillaries, blood becomes deoxygenated. - Oxygen is released from the mitochondria as a product of cellular respiration.
answer
In the blood, oxygen is bound to hemoglobin, a protein found in red blood cells.
question
after blood becomes oxygenated, - it returns to the heart, and is then pumped to the lungs. - it does not return to the heart, but goes directly to the lungs. - it does not return to the heart, but goes to the nose and mouth. - it does not return to the heart, but goes directly to capillaries that supply the body's cells with oxygen. - it returns to the heart, and is then pumped to body cells.
answer
it returns to the heart, and is then pumped to body cells.
question
Hemoglobin, - is the site of cellular respiration. - uses ATP to move oxygen from blood to body cells. - is a protein that can bind four molecules of oxygen. - is found in blood plasma. - has five subunits.
answer
is a protein that can bind four molecules of oxygen.
question
Which of the following descriptions accurately describes Boyle's law? - The pressure of gas in your lungs is inversely proportional to the volume in your lungs. - How well a gas dissolves in a liquid such as blood depends on both its partial pressure and its solubility. - The partial pressure of a gas in the air you breathe in is equal to the total atmospheric pressure times the fractional concentration of the gas.
answer
The pressure of gas in your lungs is inversely proportional to the volume in your lungs. Boyle's Law describes how air moves into and out of the lungs during inspiration and expiration. By changing the volume of the thoracic cavity, the pressure changes in the lungs. Increasing volume of the thoracic cavity leads to a decreased pressure, causing air to flow into the lungs (down its pressure gradient) and thus causing inspiration.
question
Which muscles, when contracted, would increase the volume of air in the thoracic cavity?
answer
diaphragm and external intercostals. contraction of both the diaphragm (the diaphragm flattens) and the external intercostals (pulls the ribs up and out) will increase the volume of the thoracic cavity. This will cause air to move into the lungs (inspiration).
question
Which pressure is the result of the natural tendency of the lungs to decrease their size (because of elasticity) and the opposing tendency of the thoracic wall to pull outward and enlarge the lungs? - atmospheric pressure - intrapulmonary pressure - intrapleural pressure
answer
intrapleural pressure. the lungs tend to decrease their size while the chest wall tends to pull the thorax outward. This makes the intrapleural pressure more negative than the other two pressures (described as subatmospheric), thus keeping the lungs inflated.
question
During an allergic reaction, which of the following would aid respiration? - acetylcholine (ACh) - an increase in the parasympathetic nervous system - epinephrine - histamine
answer
epinephrine. during an allergic reaction, there is increased resistance in the bronchioles and epinephrine dilates the bronchioles, thus making it easier to breathe. Epinephrine is released from the adrenal gland during stressful situations. People with severe allergies carry an EpiPen in case the allergic reaction produces anaphylaxis.
question
If the transpulmonary pressure equals zero, what will happen to the lung?
answer
The lung will collapse. the transpulmonary pressure creates the suction that keeps the lungs inflated. When room air enters the pleural space, transpulmonary pressure is zero and the lungs deflate - this is known as a pneumothorax.
question
Normally, the lungs function in a fairly high state of compliance. Which of the following could cause lung compliance to be abnormally high or low? - atelectasis - pulmonary fibrosis - emphysema - All of the above are correct.
answer
All of the above are correct.
question
Which of the following is not a physical factor that influences pulmonary ventilation? - partial pressure of oxygen in the air - alveolar surface tension - lung compliance - airway resistance
answer
partial pressure of oxygen in the air. Pulmonary ventilation is affected by pressure of air in various respiratory structures. Partial pressures of individual gases in the air affect the diffusion and dissolving of these gasses into and out of the blood.
question
Which of the following creates an adhesive force that prevents separation of the parietal and visceral pleurae during ventilation? - lung elasticity - alveolar fluid surface tension - negative intrapleural pressure - negative intrapulmonary pressure
answer
negative intrapleural pressure. A negative respiratory pressure refers to a pressure that is less than atmospheric pressure (Patm). Intrapleural pressure (Pip) is the negative pressure in the pleural cavity, which creates a partial vacuum between the visceral and parietal pleurae. This partial vacuum (negative Pip), along with the surface tension produced by the pleural fluid, holds the visceral and parietal pleurae together, thereby connecting the lungs to the thorax wall. Equilibration between Patm and Pip, which would occur if air is allowed to enter the intrapleural cavity, will result in lung collapse.
question
__________ pressure, the difference between the intrapulmonary and intrapleural pressures, prevents the lungs from collapsing. - Atmospheric - Intra-alveolar - Transpulmonary - Transthoracic
answer
Transpulmonary. The transpulmonary pressure is the difference between the intrapulmonary and intrapleural pressures. It is this pressure that keeps the air spaces of the lungs open, or, phrased another way, keeps the lungs from collapsing.
question
Quiet inspiration is __________, and quiet expiration is __________. - a passive process; an active process - an active process; also an active process - an active process; a passive process - a passive process; also a passive process
answer
an active process; a passive process. During quiet breathing, inspiration requires muscular contractions of the diaphragm and external intercostals, while expiration occurs passively due to the elastic recoil of the lungs and the collapsing force of alveolar fluid surface tension.
question
True or False: To produce the pressure gradient responsible for inspiration, thoracic volume must first increase in order to decrease intrapulmonary pressure relative to atmospheric pressure.
answer
True. During quiet inspiration, muscular contractions of the diaphragm and external intercostal muscles increase thoracic volume. Due to the coupling of the parietal and visceral pleurae, an increase in thoracic volume results in an increase in lung volume. As illustrated by Boyle's law, this increase in lung volume results in a decrease in lung (intrapulmonary) pressure. With intrapulmonary pressure now lower than atmospheric pressure, the pressure gradient required for airflow into the lungs is achieved.
question
Which of the following factors benefits pulmonary ventilation by making inspiration easier? - reduced lung compliance - increased airway resistance - increased alveolar surface tension - increased secretion of surfactant
answer
increased secretion of surfactant. Surfactant decreases the attraction between water molecules lining the interior surface of the alveoli. As a result, the surface tension of alveolar fluid is reduced, and less energy is needed to overcome those forces to expand the lungs during inspiration.
question
True or False: Intrapleural pressure is normally about 4 mm Hg less than the pressure in the alveoli.
answer
True.
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True or False: Atelectasis (lung collapse) renders the lung useless for ventilation.
answer
True.
question
Air moves out of the lungs when the pressure inside the lungs is ________.
answer
greater than the pressure in the atmosphere.
question
Which of the following is true regarding normal quiet expiration of air? - It depends on the complete lack of surface tension on the alveolar wall. - It requires contraction of abdominal wall muscles. - It is driven by increased blood CO2 levels. - It is a passive process that depends on the recoil of elastic fibers that were stretched during inspiration.
answer
It is a passive process that depends on the recoil of elastic fibers that were stretched during inspiration.
question
Intrapulmonary pressure is the ________. - negative pressure in the intrapleural space - pressure within the pleural cavity - difference between atmospheric pressure and respiratory pressure - pressure within the alveoli of the lungs
answer
pressure within the alveoli of the lungs
question
The relationship between gas pressure and gas volume is described by ________.
answer
Boyle's Law.
question
Surfactant helps to prevent the alveoli from collapsing by ________. - protecting the surface of alveoli from dehydration and other environmental variations - humidifying the air before it enters - warming the air before it enters - interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid
answer
interfering with the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid.
question
Which of the choices below describes the forces that act to pull the lungs away from the thorax wall and thus collapse the lungs? - compliance and transpulmonary pressures - compliance and the surface tension of the alveolar fluid - the natural tendency for the lungs to recoil and the surface tension of the alveolar fluid - the natural tendency for the lungs to recoil and transpulmonary pressures
answer
the natural tendency for the lungs to recoil and the surface tension of the alveolar fluid.
question
What is the term that refers to the movement of air into and out of the lungs?
answer
Pulmonary ventilation.
question
The major nonelastic source of resistance to air flow in the respiratory passageways is ________.
answer
Friction.
question
Which of the following determines lung compliance? - muscles of inspiration - alveolar surface tension - airway opening - flexibility of the thoracic cage
answer
alveolar surface tension.
question
Inspiration occurs when the ________ is less than the ________.
answer
Inspiration occurs when the intrapulmonary pressure is less than the atmospheric pressure
question
Which respiratory-associated muscles would contract or relax during forced expiration, for example blowing up a balloon?
answer
internal intercostals and abdominal muscles would contract.
question
Which pressure actually keeps the lungs from collapsing?
answer
transpulmonary pressure
question
Which of the following is INCORRECT? - Gas flow equals pressure gradient over resistance. - Pressure gradient equals gas flow over resistance. - Resistance equals pressure gradient over gas flow. - The amount of gas flowing in and out of the alveoli is directly proportional to the difference in pressure or pressure gradient between the external atmosphere and the alveoli.
answer
Pressure gradient equals gas flow over resistance.
question
Select the correct statement about the physical factors influencing pulmonary ventilation. - A lung that is less elastic will require less muscle action to perform adequate ventilation. - A decrease in compliance causes an increase in ventilation. - Surfactant helps increase alveolar surface tension. - As alveolar surface tension increases, additional muscle action will be required.
answer
As alveolar surface tension increases, additional muscle action will be required.
question
For inspiration of air, which of the following happens first? - thoracic cavity volume decreases - air (gases) flows into lungs - intrapulmonary pressure drops - diaphragm descends, thoracic volume begins to increase, and rib cage rises
answer
diaphragm descends, thoracic volume begins to increase, and rib cage rises.
question
Which law describes the relationship between the pressure and volume of a gas?
answer
Boyle's Law.
question
Which of the pressures rises and falls with the phases of breathing but eventually equalizes with the pressure of the air in the environment?
answer
intrapulmonary pressure. Intrapulmonary pressure rises when the thorax volume is reduced (during exhalation) and drops when the thorax volume rises (during inhalation). When there is no change in thorax volume, intrapulmonary pressure equalizes with the atmospheric pressure.
question
Which of the pressures must remain negative to prevent lung collapse?
answer
intrapleural pressure. Intrapleural pressure is created as the lungs attempt to shrink away from the thoracic wall. This negative pressure, as well as the adherence due to moisture, is what keeps the lungs from collapsing.
question
Calculate the actual intrapleural pressure if atmospheric pressure is 765 millimeters of mercury, assuming that the subject is at rest (not inhaling or exhaling).
answer
761 millimeters of mercury. The intrapleural pressure is always about 4 millimeters of mercury less than the intrapulmonary pressure, and the intrapulmonary pressure is equal to the atmospheric pressure if the subject is at rest.
question
Which of the following is an INCORRECT statement relating to the airflow to the lungs? - When the sternocleidomastoid is activated, expiration occurs. - When the diaphragm is activated, inspiration occurs. - When the sternum is depressed, expiration occurs. - When the ribs are elevated, inspiration occurs.
answer
When the sternocleidomastoid is activated, expiration occurs. The sternocleidomastoid muscle elevates the ribs, assisting in inspiration.
question
Which of the following, if activated as a group, would result in inspiration? - external intercostals, sternocleidomastoid, diaphragm - rectus abdominis, sternocleidomastoid, diaphragm - rectus abdominis, internal intercostals, scalenes - Transversus thoracis, internal intercostals, diaphragm
answer
external intercostals, sternocleidomastoid, diaphragm
question
Which muscles are activated during forced expiration?
answer
the internal intercostal, oblique, and transversus muscles
question
This lung volume CANNOT be directly measured using a spirometer.
answer
residual volume.
question
Which lung volume tends to be the largest in healthy male and female adults?
answer
inspiratory reserve volume.
question
A patient with a restrictive lung disease such as tuberculosis is likely to see an increase in his or her __________.
answer
breathing rate. Restrictive lung diseases decrease vital capacity, total lung capacity, functional residual capacity, and residual volume. To provide adequate ventilation, the alveolar ventilation rate must increase.
question
Which of the following behaviors would most likely result in an increased alveolar ventilation rate as compared to that of normal breathing? - slow, deep breathing - breathing slowly into a paper bag - rapid, shallow breathing - breathing rapidly into a paper bag
answer
slow, deep breathing. Slow breathing provides adequate time for gases to pass into the alveoli, while breathing deeply increases the number of alveoli being utilized. The combination of these factors increases effective ventilation, or alveolar ventilation rate.
question
What is the amount of air that is normally ventilated in one breath?
answer
tidal volume. A tidal volume is the amount of air in a normal breath under resting conditions. One way to remember this is to compare tidal breathing to ocean tides that go in and out, day and night, without ceasing.
question
Which of the following findings consistently matches pulmonary function with problems with ventilation? - A person with a decreased FVC and FEV1 has an obstructive disorder. - A person with a decreased FVC and a normal FEV1 has a restrictive disorder. - A person with a FEV1 below 80% has a restrictive disorder. - A person with decreased FVC and increased FEV1 has an obstructive disorder.
answer
A person with a decreased FVC and a normal FEV1 has a restrictive disorder. Restrictive diseases, such as tuberculosis, decrease FVC but do not affect flow, so FEV1 stays the same.
question
Which of the following statements is true? - Slow, deep breathing makes less gas available for gas exchange. - Breathing rate and depth do not affect gas exchange. - Normal breathing rates and depth provide the most oxygen for exchange. - Rapid shallow breathing can reduce the amount of gas exchange without changing the total amount of gas moved in a minute.
answer
Rapid shallow breathing can reduce the amount of gas exchange without changing the total amount of gas moved in a minute. Minute ventilation, the total amount of gas moved in a minute, might not be reduced during rapid shallow breathing, but because much of that gas remains in the dead space, less gas is available for gas exchange.
question
True or False: Residual volume can be measured with a spirometer.
answer
False. Residual volume cannot be measured; it has to be estimated, generally based on the size and sex of an individual. The volume cannot be detected with a spirometer because the volume of residual air left in the lungs at the end of expiration cannot pass through a spirometer to be measured.
question
True or False: During normal quiet breathing, males breathe 25% more than females.
answer
False.
question
True or False: The alveolar ventilation rate is the best index of effective ventilation.
answer
True.
question
True or False: The average individual has 500 ml of residual volume in his lungs.
answer
False.
question
Tidal volume is air ________.
answer
exchanged during normal breathing.
question
The lung volume that represents the total volume of exchangeable air is the ________.
answer
tidal capacity.
question
The amount of air that can be inspired above the tidal volume is called ________.
answer
inspiratory reserve volume.
question
Inspiratory capacity is ________.
answer
the total amount of air that can be inspired after a tidal expiration.
question
Spirometry results reveal a vital capacity of two liters which is well below the predicted value of five liters. This suggests which disorder?
answer
restrictive disease.
question
Using spirometry, a patient discovers their forced expiratory volume (FEV) after the first second is 40%. What does this suggest?
answer
COPD.
question
_________________ : TV + IRV + ERV + RV
answer
Total lung capacity : TV + IRV + ERV + RV
question
_____________ : TV + IRV + ERV
answer
Vital capacity : TV + IRV + ERV
question
_______________ : ERV + RV
answer
Functional residual capacity : ERV + RV
question
_____________ : TV + IRV
answer
Inspiratory capacity : TV + IRV
question
True or False: Henry's law of partial pressures states that when a gas is in contact with a liquid, that gas will dissolve in the liquid in proportion to its partial pressure.
answer
True.
question
True or False: Ventilation perfusion coupling means that more blood flows past functional alveoli than past nonfunctional alveoli.
answer
True.
question
True or False: Dalton's law of partial pressures states that the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture.
answer
True.
question
The statement, "in a mixture of gases, the total pressure is the sum of the individual partial pressures of gases in the mixture" paraphrases ________.
answer
Dalton's Law.
question
The local matching of blood flow with ventilation is ________.
answer
ventilation-perfusion coupling.
question
Hemoglobin has a much greater affinity for carbon monoxide than oxygen. Which principle explains why a hyperbaric chamber (containing high levels of oxygen) can treat carbon monoxide poisoning?
answer
Henry's Law.
question
Which phenomenon determines the direction of respiratory gas movement?
answer
partial pressure gradient.
question
35-Year-Old Female with Chest Trauma Barbara Joley was in a major car accident. When EMS managed to free her from the wreckage, she was cyanotic and apneic (not breathing). Her heart was still beating, but her pulse was fast and thready. The emergency medical technician reported that when Barbara was found, her head was cocked at a peculiar angle and it looked like she had a fracture at the level of the C2 vertebra. The following questions refer to these observations. Barbara's cyanosis can best be explained by which of the following?
answer
The level of O2 in her blood has decreased because her breathing has stopped. Her alveolar PO2 will fall, so there is less oxygen to load onto hemoglobin. In her peripheral tissues, the small amount of oxygen that hemoglobin carries will be consumed, leaving these tissues with a bluish tinge.
question
35-Year-Old Female with Chest Trauma Barbara Joley was in a major car accident. When EMS managed to free her from the wreckage, she was cyanotic and apneic (not breathing). Her heart was still beating, but her pulse was fast and thready. The emergency medical technician reported that when Barbara was found, her head was cocked at a peculiar angle and it looked like she had a fracture at the level of the C2 vertebra. The following questions refer to these observations. How do Barbara's recorded injuries relate to the pneumothorax?
answer
Barbara's fractured ribs probably punctured her lung tissue and allowed air within the lung to enter the pleural cavity.
question
Which of the following is the primary factor in oxygen's attachment to, or release from, hemoglobin? - partial pressure of carbon dioxide - blood pH - temperature - partial pressure of oxygen
answer
partial pressure of oxygen. Partial pressure of oxygen is the primary factor affecting the binding of oxygen with hemoglobin.
question
What is the primary form in which carbon dioxide is carried in blood?
answer
as a bicarbonate ion in plasma. About 70% CO2 is transported as bicarbonate. When dissolved CO2 diffuses into RBCs, it combines with water, forming carbonic acid (H2CO3). H2CO3 is unstable and dissociates into hydrogen ions and bicarbonate (HCO3-) ions. Once generated, bicarbonate moves quickly from the RBCs into the plasma, where it is carried to the lungs.
question
Your patient has been transported to the emergency department by EMS after a motor vehicle accident with an endotracheal tube in place. You note that his breath sounds are louder on the right side. You are alerted to which of the following situations? - All of the listed responses are correct. - Your patient may have a left pneumothorax. - Hemorrhage into the left pleural space (hemothorax) has compressed the left lung. - The endotracheal tube has been inserted too far, with its tip in the right main bronchus, preventing the left lung from receiving air.
answer
All of the listed responses are correct.
question
Which form of CO2 transport accounts for the least amount of CO2 transported in blood?
answer
dissolved in plasma. Most CO2 is transported in the blood bound to hemoglobin (forming carbaminohemoglobin) or in the form of bicarbonate ions. The latter occurs as CO2 entering the blood combines with water to form carbonic acid (H2CO3), which then dissociates into hydrogen ions and bicarbonate ions (HCO3โˆ’). A very small percentage is dissolved into the plasma.
question
True or False: If your core temperature becomes colder, it is more difficult for oxygen to dissociate from hemoglobin at any PO2.
answer
True. A decrease in temperature increases hemoglobin's binding affinity for O2, making it more difficult to dissociate (unload) O2 from hemoglobin. This is illustrated by the leftward shift of the oxygen-hemoglobin dissociation curve.
question
Which form of hypoxia reflects poor O2 delivery resulting from too few RBCs or from RBCs that contain abnormal or too little hemoglobin? - histotoxic hypoxia - ischemic (stagnant) hypoxia - hypoxemic hypoxia - anemic hypoxia
answer
anemic hypoxia
question
True or False: The largest amount of carbon dioxide is transported in the bloodstream in the form of carbonic anhydrase.
answer
False.
question
True or False: Increased temperature results in decreased O2 unloading from hemoglobin.
answer
False.
question
True or False: As carbon dioxide enters systemic blood, it causes more oxygen to dissociate from hemoglobin (the Haldane effect), which in turn allows more CO2 to combine with hemoglobin and more bicarbonate ions to be generated (the Bohr effect).
answer
False.
question
True or False: Oxygenated hemoglobin releases oxygen more readily when the pH is more basic.
answer
False.
question
The Bohr effect describes the tendency for hemoglobin to more readily unload oxygen under which conditions?
answer
decreased pH and increased PCO2.
question
In the plasma, the quantity of oxygen in solution is ________.
answer
only about 1.5% of the oxygen carried in blood.
question
Which of the following counteracts the movement of bicarbonate ions from the RBC? - the Haldane effect - release of hydrogen ion - the Bohr effect - chloride shifting
answer
chloride shifting.
question
Possible causes of hypoxia include ________. - getting very cold - obstruction of the esophagus - too little oxygen in the atmosphere - taking several rapid deep breaths
answer
too little oxygen in the atmosphere.
question
Which statement about CO2 is FALSE? - Its concentration in the blood is decreased by hyperventilation. - More CO2 dissolves in the blood plasma than is carried in the RBCs. - CO2 concentrations are greater in venous blood than arterial blood. - Its accumulation in the blood is associated with a decrease in pH.
answer
More CO2 dissolves in the blood plasma than is carried in the RBCs.
question
How is the bulk of carbon dioxide transported in blood?
answer
as bicarbonate ions in plasma after first entering the red blood cells.
question
Which of the following incorrectly describes mechanisms of CO2 transport? - as bicarbonate ions in plasma - just over 20% of CO2 is carried in the form of carbaminohemoglobin - 7-10% of CO2 is dissolved directly into the plasma - attached to the heme part of hemoglobin
answer
attached to the heme part of hemoglobin.
question
According to the oxygen-hemoglobin dissociation curve, PO2 in the lungs of 100 mm Hg results in Hb being 98% saturated. At high altitude, there is less O2. At a PO2 in the lungs of 80 mm Hg, Hb would be ________ saturated.
answer
95%
question
What is an appropriate response to carbon monoxide (CO) poisoning?
answer
hyperbaric oxygen chamber to increase PO2 and clear CO from the body.
question
Which of the choices below is NOT a factor that promotes oxygen binding to and dissociation from hemoglobin? - number of red blood cells - temperature - partial pressure of oxygen - partial pressure of carbon dioxide
answer
number of red blood cells
question
Select the correct statement about oxygen transport in blood. - A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal. - During normal activity, a molecule of hemoglobin returning to the lungs carries one molecule of O2. - During conditions of acidosis, hemoglobin is able to carry oxygen more efficiently. - Increased BPG levels in the red blood cells enhance oxygen-carrying capacity.
answer
A 50% oxygen saturation level of blood returning to the lungs might indicate an activity level higher than normal.
question
Which of the following does NOT influence hemoglobin saturation? - partial pressure of carbon dioxide - BPG - temperature - nitric oxide
answer
nitric oxide.
question
The Bohr effect refers to the unloading of ________ in a RBC due to declining blood pH.
answer
oxygen
question
Which of the following would induce the loss of oxygen from the hemoglobin and the blood? - a drop in blood pH - decreases in plasma carbon dioxide - a decrease in blood temperature - increase in hemoglobin that has oxygen bound to it already
answer
a drop in blood pH. The pH in blood tends to drop when plasma reacts with carbon dioxide, a common condition in tissue. This pH drop causes weakening of the Hb-O2 bond, a phenomenon called the Bohr effect.
question
What is the most common method of carbon dioxide transport?
answer
as bicarbonate ions in the plasma. Carbon dioxide reacts with water inside RBCs to form carbonic acid, which dissociates into bicarbonate and hydrogen ions. About 70% of carbon dioxide travels in the plasma as bicarbonate.
question
_______ has a greater partial pressure in the pulmonary capillaries than in the alveoli, so it diffuses into the _______. -
answer
CO2 ; alveoli
question
Despite the fact that the partial pressure difference is so much smaller for CO2, why is there as much CO2 exchanged between the alveoli and blood as there is O2?
answer
CO2 is much more soluble in blood than O2.
question
How would the partial pressures of CO2 and O2 change in an exercising muscle?
answer
The partial pressure of O2 would decrease, and the partial pressure of CO2 would increase to produce ATP.
question
Which way would O2 and CO2 diffuse during internal respiration?
answer
O2 would diffuse into the cells, and CO2 would diffuse into the systemic capillaries because the the Po2 would be higher in the systemic capillaries, and the Pco2 would be higher in the tissues.
question
Internal and external respiration depends on several factors. Which of the following is NOT an important factor in gas exchange? - available surface area - the molecular weight of the gas - partial pressure of the gases - rate of blood flow through the tissue
answer
the molecular weight of the gas.
question
Which statement is correct? - The greater the available surface area the lower the amount of gas exchange during internal respiration. - During external respiration, equilibrium is reached for O2 when the partial pressure for O2 in the pulmonary capillaries and the alveoli are the same. - During external respiration, oxygen is unloaded from the blood. - During internal respiration, carbon dioxide is unloaded from the blood.
answer
During external respiration, equilibrium is reached for O2 when the partial pressure for O2 in the pulmonary capillaries and the alveoli are the same.
question
Which of the following best describes how Boyle's law relates to the mechanics of breathing? - If lung volume decreases, intrapleural pressure increases, forcing air into the lungs. - If lung volume increases, intrapleural pressure decreases, drawing air into the lungs. - If lung volume increases, intrapleural pressure increases, forcing air out of the lungs. - If lung volume decreases, intrapleural pressure decreases, forcing air out of the lungs.
answer
If lung volume increases, intrapleural pressure decreases, drawing air into the lungs. Boyle's law shows that pressure and volume are inversely related. If the volume of a space increases, the pressure in that space must decrease.
question
Which of the following statements accurately describes transpulmonary pressure? - Transpulmonary pressure reflects the pressure of air surrounding the body at any given time. - Transpulmonary pressure is usually near 4 mm Hg - Transpulmonary pressure is the pressure in the alveoli during breathing phases. - Transpulmonary pressure is the pressure in the pleural cavity during breathing phases.
answer
Transpulmonary pressure is usually near 4 mm Hg.
question
Which of the following could be responsible for an increase in intrapulmonary pressure? - a decrease in intrapleural pressure - inspiration - an increase in lung volume - a decrease in lung volume
answer
a decrease in lung volume. According to Boyle's law, a decrease in volume will produce an increase in pressure, at least until the air moves and pressures equalize.
question
Which of the following would likely result in a collapsed lung? - a strong enough contraction of the diaphragm - an increase in transpulmonary pressure - a decrease in intrapulmonary pressure to atmospheric pressure - an opening in the chest wall that allows the intrapleural pressure to equal atmospheric pressure
answer
an opening in the chest wall that allows the intrapleural pressure to equal atmospheric pressure. If the chest wall is penetrated and air can enter the pleural cavity, the intrapleural pressure will no longer be negative compared to atmospheric pressure. Without a negative intrapleural pressure, there are no forces to prevent lung collapse.
question
What is the most powerful respiratory stimulant in a healthy person?
answer
arterial blood carbon dioxide level.
question
Which of the following arterial blood levels is the most powerful respiratory stimulant? - arterial pH - low O2 level - low CO2 level - rising CO2 levels
answer
rising CO2 levels. Of all the chemicals influencing respiration, CO2 is the most potent and the most closely controlled. An elevation of only 5 mmHg in arterial PCO2 doubles alveolar ventilation, even when arterial O2 levels and pH haven't changed. When PO2 and pH are below normal, the response to elevated PCO2 is even greater. On the other hand, arterial PO2 must drop substantially, to at least 60 mmHg, before O2 levels become a major stimulus for increased ventilation.
question
True or False: A drop in blood pH is likely to cause a slower breathing rate.
answer
False.
question
True or False: The inflation (Hering-Breuer) reflex is a potentially dangerous response that may cause overinflation of the lung.
answer
False.
question
True or False: Strong emotions and pain, acting through the limbic system and hypothalamus, send signals to the respiratory centers that modulate respiratory rate and depth.
answer
True.
question
The most powerful respiratory stimulus for breathing in a healthy person is ________.
answer
increase in carbon dioxide levels.
question
Which of the following is NOT a stimulus for breathing? - arterial PO2 below 60 mm Hg - rising blood pressure - rising carbon dioxide levels - acidosis resulting from CO2 retention
answer
rising blood pressure
question
Respiratory control centers are located in the ________.
answer
Medulla and pons.
question
Factors that influence the rate and depth of breathing include ________. - temperature of alveolar air - voluntary cortical control - thalamic control - stretch receptors in the alveoli
answer
voluntary cortical control.
question
The symptoms of hyperventilation may be averted by breathing into a paper bag because it ________. - helps retain oxygen in the blood - lowers blood pH levels - helps retain carbon dioxide in the blood - reduces brain perfusion by constricting cerebral blood vessels
answer
helps retain carbon dioxide in the blood.
question
Which center is located in the pons? - pontine respirator group (PRG) - expiratory - inspiratory - pacemaker neuron center
answer
pontine respirator group (PRG).
question
Which group initiates inspiration?
answer
ventral respiratory group (VRG).
question
What serves as the origin for the phrenic nerve?
answer
the cervical plexus
question
Which of the following modifies and smoothes the respiratory pattern? - pontine respiratory centers - dorsal respiratory group (DRG) - diencephalon - ventral respiratory group (VRG)
answer
pontine respiratory centers. The pontine respiratory centers transmit impulses to the ventral respiratory group (VRG) of the medulla to smooth the respiratory pattern and modify it based on activities such as exercise and sleeping.
question
Which of the following inhibits/reduces the respiratory rate? - a rise in body temperature - elevated carbon dioxide levels in the blood - stimulation of stretch receptors in the lungs - partial pressure of oxygen below 60 millimeters of mercury at chemoreceptors
answer
stimulation of stretch receptors in the lungs. The stimulation of stretch receptors in the lungs reduces the urge to inspire air. When the lungs recoil back to a relaxed shape during expiration, the urge to breathe is again initiated (inflation reflex).
question
Which of the following conditions or scenarios increases the respiratory rate? - a drop in carbon dioxide levels in the blood - an increase in partial pressure of oxygen - alkalosis - acidosis
answer
acidosis. A low pH in blood indicates a high level of carbon dioxide, which in turn increases the urge to ventilate the lungs.
question
Which of the following is correct regarding acclimatization? - At high altitudes, hemoglobin's affinity for O2 is increased because BPG concentrations increase. - Decreases in arterial PO2 cause the peripheral chemoreceptors to become less responsive to increases in PCO2. - High-altitude conditions always result in lower-than-normal hemoglobin saturation levels because less O2 is available to be loaded. - When blood O2 levels decline, the kidneys produce more erythropoietin, which stimulates breakdown of red blood cells in the spleen.
answer
High-altitude conditions always result in lower-than-normal hemoglobin saturation levels because less O2 is available to be loaded.
question
The erythrocyte (red blood cell) count increases after a while when an individual goes from a low to a high altitude because the ________. - basal metabolic rate is higher at high altitudes - temperature is lower at higher altitudes - concentration of oxygen and/or total atmospheric pressure is lower at high altitudes - concentration of oxygen and/or total atmospheric pressure is higher at higher altitudes
answer
concentration of oxygen and/or total atmospheric pressure is lower at high altitudes.
question
The normal CFTR protein is a membrane channel protein that controls chloride ion flow into and out of cells. The sweat of cystic fibrosis patients has an abnormally high concentration of salt (NaCl) because the presence of faulty CFTR proteins directly causes ______. - hypersecretion of sodium ions by sweat-producing cells - reduced absorption of certain anions from sweat into the sweat duct cells - increased pumping of ions by the sodium-potassium pump into secreted sweat - reduced pumping of chloride ions into sweat
answer
reduced absorption of certain anions from sweat into the sweat duct cells. This channel, in the sweat ducts, facilitates the movement of chloride into and out of cell cytoplasm. When the CFTR protein does not work, chloride is trapped inside cells. Because chloride is negatively charged, this creates a difference in the electrical potential inside and outside the cell, causing cations to cross into the cell. Sodium is the most common cation in the extracellular space, and the combination of sodium and chloride creates the salt that is lost in high amounts in the sweat of individuals with CF.
question
Which of the following types of drugs would NOT be appropriate for a patient with chronic asthma? - An albuterol inhaler, which enhances sympathetic input to bronchioles - Prednisone, which blunts the immune response - Epinephrine - A cough suppressant, such as dextromethorphan
answer
A cough suppressant, such as dextromethorphan.
question
Your patient has several cracked ribs from a car accident, which of these would you expect from his or her blood gases? - Decreased PCO2 and increased pH - Elevated PCO2 and decreased pH - Decreased PCO2 and decreased pH - Elevated PCO2 and increased pH
answer
Elevated PCO2 and decreased pH.
question
True or False: In chronic bronchitis, mucus production is decreased and this leads to the inflammation and fibrosis of the mucosal lining of the bronchial tree.
answer
False.
question
True or False: Labored breathing is termed hypercapnia.
answer
False.
question
Which of the disorders below is characterized by destruction of the walls of the alveoli producing abnormally large air spaces that remain filled with air during exhalation? - tuberculosis - pneumonia - coryza - emphysema
answer
emphysema.
question
Chronic bronchitis is a component of chronic obstructive pulmonary disease, or COPD, in smokers. What is the other main component of this disease?
answer
emphysema.
question
Viral sinusitis may be caused by a direct extension of an upper respiratory infection involving the __________.
answer
Pharynx.