Mastering A&P 2 CH 22 HW
Which of the following is NOT a benefit of breathing through the nose? -filtration of the air entering the nasal cavity -recovering heat and moisture from the air leaving the nasal cavity -the production of smooth, laminar airflow as air passes by the nasal conchae -heating and moistening the air entering the nasal cavity
-the production of smooth, laminar airflow as air passes by the nasal conchae Correct 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 μm make it past the nasal cavity.
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
-visceral pleura of the same lung Correct 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..
Emphysema can result in an ______. -increased level of carbaminohemoglobin -increased lev el of deoxyhemoglobin -increased likelihood of the skin of Caucasians developing a slightly blue coloration -All of the listed responses are correct
All of the listed responses are correct. Correct Using your textbook, review the structure of hemoglobin and how oxygen and carbon dioxide bind. Additionally review the pathophysiology of emphysema.
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, ? -The capillary walls are more permeable to CO2 than O2. -CO2 is much more soluble in blood than O2. -CO2 is a smaller molecule and diffuses faster than O2O2.
CO2 is much more soluble in blood than O2 Correct Yes, because CO2CO2 is very soluble in blood, it does not require as large a pressure gradient as O2O2.
_______ has a greater partial pressure in the pulmonary capillaries than in the alveoli, so it diffuses into the -O2; pulmonary cavities -CO2; pulmonary capillaries -CO2; alceoli -O2; alveoli
CO2; alveoli Correct Yes, CO2 diffuses along its partial pressure gradient from the pulmonary capillaries into the alveoli until equilibrium is reached.
Which of the following best describes the chloride shift as seen in the figure? -Chloride is taken out of the blood to counterbalance the inflow of carbon dioxide. -Chloride rushes into RBCs to counterbalance the outflow of bicarbonate. -Chloride binds to bicarbonate, which allows more of it to be carried in the bloodstream. -Chloride is removed from hemoglobin when carbon dioxide binds to it.
Chloride rushes into RBCs to counterbalance the outflow of bicarbonate. Correct The outflow of negative bicarbonate ions from RBCs is balanced by the inflow of chloride ions.
Which statement is correct? -The greater the available surface area the lower the amount of gas exchange during internal respiration. -During internal respiration, carbon dioxide is unloaded from the blood. -During external respiration, oxygen is unloaded from the blood. -During external respiration, equilibrium is reached for O2O2 when the partial pressure for O2O2 in the pulmonary capillaries and the alveoli are the same.
During external respiration, equilibrium is reached for O2O2 when the partial pressure for O2O2 in the pulmonary capillaries and the alveoli are the same. Correct Yes, equilibrium is reached for O2O2 when the partial pressure of O2O2 in the pulmonary capillaries and the tissue cells are the same.
How would the partial pressures of O2O2 and CO2CO2 change in an exercising muscle? -The partial pressure of O2O2 would increase, and the partial pressure of CO2CO2 would decrease. -The partial pressures of O2O2 and CO2CO2 would remain unchanged. -The partial pressure of O2O2 would decrease, and the partial pressure of CO2CO2 would increase.
The partial pressure of O2O2 would decrease, and the partial pressure of CO2CO2 would increase. Correct Yes, cells use O2O2 and produce CO2CO2 during cellular respiration to produce ATP. Exercising muscles need more ATP.
Which of the following descriptions accurately describes Boyle's law? -How well a gas dissolves in a liquid such as blood depends on both its partial pressure and its solubility. -The pressure of gas in your lungs is inversely proportional to the volume in your lungs. -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.
The pressure of gas in your lungs is inversely proportional to the volume in your lungs. Correct Yes, 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.
If your core temperature becomes colder, it is more difficult for oxygen to dissociate from hemoglobin at any PO2. -True -False
True Correct 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.
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 II alveolar cells -type I alveolar cells
Type II Alveolar Cells Correct 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.
Quiet inspiration is __________, and quiet expiration is __________. -an active process; a passive process -an active process; also an active process -a passive process; also a passive process -a passive process; an active process
an active process; a passive process Correct 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.
What is the most common method of carbon dioxide transport? -as bicarbonate ions in the plasma -chemically bound to hemoglobin as oxyhemoglobin -dissolvfed in the plasma -chemically bound to hemoglobin as carbaminohemoglobin
as bicarbonate ions in the plasma Correct 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.
A patient with a restrictive lung disease such as tuberculosis is likely to see an increase in his or her __________. -vital capacity -functional residual capacity -breathing rate -residual volume
breathing rate Correct 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.
Which of the following structures would be the LEAST vulnerable to damage caused by oxygen toxicity? brain spleen muscles costal cartilages
costal cartilages Cartilage is normally avascular and receives oxygen by diffusion from surrounding capillaries
As a result of hyperventilation, what will happen to the partial pressures of CO2 (pCO2) and pH? -decreased pCO2 and decreased pH -increased pCO2 and decreased pH -increased pCO2 and increased pH -decreased pCO2 and increased pH
decrease pCO2 and increased pH Correct Yes, pCO2 would decrease and pH would increase. As CO2 is blown off, H+ would decrease, thus increasing pH.
Which muscles, when contracted, would increase the volume of air in the thoracic cavity? -internal intercostals and external oblique -diaphragm and internal intercostals -diaphragm and external intercostals
diaphragm and external intercostals Correct Yes, 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).
What structure prevents food and liquids from entering the trachea? -glottis -epiglottis -laryngeal prominence -vestibular folds
epiglottis Correct 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.
During an allergic reaction, which of the following would aid respiration? -acetylcholine (ACh) -an increase in the parasympathetic nervous system -epinephrine -histamine
epinephrine Correct Yes, 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
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
external respiration: CO2 diffuses into the blood stream Correct CO2 diffuses into the blood as it passes through the systemic capillaries of the tissues; this is internal respiration.
What directly stimulates the central chemoreceptors, thus increasing respiration? -H+ (hydrogen ions) low O2 (oxygen high CO2 (carbon dioxide) high pH
H+ (hydrogen ions) Correct Yes, hydrogen ions (H+) stimulate the central chemoreceptors. CO2 is converted to H+ in the extracellular fluid of the brain.
Which lung volume tends to be the largest in healthy male and female adults? -tidal volume -inspiratory reserve volume -expiratory reserve volume -residual volume
inspiratory reserve volume Correct In most healthy adults, inspiratory reserve volume is greater than tidal volume, expiratory reserve volume, and residual volume.
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? -intrapulmonary pressure -atmospheric pressure -intrapleural pressure
intrapleural pressure Correct Yes, 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.
In pneumothorax, the lung collapses because ______. -intrapleural pressure is lower than trans-pulmonary pressure -intrapleural pressure is equal to intrapulmonary pressure -intrapulmonary pressure is lower than trans -pulmonary pressure intrapulmonary pressure is higher than atmospheric pressure
intrapleural pressure is equal to intrapulmonary pressure Correct 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.
Hemoglobin -uses ATP to move oxygen from blood to body cells. has five subunits. -is the site of cellular respiration. -is found in blood plasma. -is a protein that can bind four molecules of oxygen.
is a protein that can bind four molecules of oxygen
Which of the following helps to protect against tracheal obstruction. -carina of the trachea -trachealis muscle -larynx -tracheal cartilage
larynx Correct 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.
If the transpulmonary pressure equals zero, what will happen to the lung? -lung volume will stay the same -lungs will inflate -lungs will collapse
lungs will collapse Correct Yes, 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.
Which of the following is not a physical factor that influences pulmonary ventilation? -partial pressure of oxygen in the air -alveolar surface tension -airway resistance -lung compliance
partial pressure of oxygen in the air Correct 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.
Which of the following is an organ shared by the respiratory system and the digestive system? -pharynx -trachea -larynx -esophagus
pharynx Correct 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.
Inspiratory neurons send information to the diaphragm via what nerve? phrenic nerve intercostal nerves glossopharyngeal nerve vegus nerve
phrenic nerve Correct Yes, the phrenic nerve innervates the diaphragm. Stimulation causes the diaphragm to contract (increasing volume and decreasing pressure), thus causing inspiration.
Focus your attention on the graph shown, from the left side of the Focus Figure. The percent of O2O2 saturation of hemoglobin is plotted (on the y-axis) against PO2PO2 (mm Hg) (on the x-axis). Use this graph to complete Parts A-C below. On this graph, the y-axis (the vertical edge) tells you how much O2O2 is bound to hemoglobin (Hb). At 100%, each Hb molecule has four bound oxygen molecules. The x-axis (the horizontal edge) tells you the relative amount (partial pressure) of O2O2 dissolved in the fluid surrounding the Hb. If more O2O2 is present, more O2O2 is bound. However, because of Hb's properties (O2O2 binding strength changes with saturation), this is an S-shaped curve, not a straight line. Which of the following represents a correct statement about data presented in the graph? -In blood with 30% oxygen saturation of hemoglobin, there is a PO2PO2 of ~60 mm Hg in surrounding fluid. -In blood with 60% oxygen saturation of hemoglobin, each individual hemoglobin binds ~2.5 oxygens. -Blood with three oxygens per hemoglobin represents a saturation of PO2PO2 at ~30 mm Hg. -In blood with a PO2PO2 of 30 mm Hg, the average saturation of all hemoglobin proteins is 60%.
In blood with a PO2 of 30 mm Hg, the average saturation of all hemoglobin proteins is 60%. Correct Cooperative binding of oxygen to an individual hemoglobin protein occurs with one oxygen per hemoglobin representing 25% saturation; two oxygens per hemoglobin, 50%; three oxygens per hemoglobin, 75%; and four oxygens per hemoglobin, 100% saturation. Only collectively with all hemoglobins can there be percentages in between, as seen in the S-shaped curve graph of saturation plotted against PO2PO2 of blood.
Which way would O2O2 and CO2CO2 diffuse during internal respiration? -Both O2 and CO2 would diffuse into the systemic capillaries. -O2 would diffuse into the systemic capillaries, and CO2CO2 would diffuse into the cells. -O2 would diffuse into the cells, and CO2 would diffuse into the systemic capillaries. -O2 would diffuse into the pulmonary capillaries and CO2CO2 would diffuse into the alveoli.
O2 would diffuse into the cells, and CO2CO2 would diffuse into the systemic capillaries. Correct Yes, the PO2 would be higher in the systemic capillaries, and the PCO2PCO2 would be higher in the tissues.
Which receptors inhibit inspiration during hyperinflation of the lungs? -hypothalamic receptors irritant receptors pulmonary stretch receptors -peripheral chemoreceptors
pulmonary stretch receptors Correct Yes, inspiration stimulates the pulmonary stretch receptors (PSRs), which send input to the respiratory centers, inhibiting further inspiration.
This lung CANNOT be directly measured using a spirometer -tidal volume -residual volume -inspiratory reserve volume -expiratory reserve volume
residual volume Residual volume refers to the amount of air left in the lungs after a tidal expiration
A homeostatic control mechanism controls respiration. What acts as the effector(s) in this system? -peripheral chemoreceptors respiratory muscles central chemoreceptors medulla oblongata
respiratory muscles Correct Yes, the respiratory muscles change the volume of the thoracic cavity (and thus the pressure), resulting in inspiration and expiration.
Which of the following arterial blood levels is the most powerful respiratory stimulant? -rising CO2 levels -arterial pH -low CO2 level -low O2 level
rising CO2 level Correct 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.
What stimulates increased respiration at the beginning of exercise? -decreased plasma oxygen levels -increased hydrogen ion levels -sensory input from receptors in joints, neural input from the motor cortex, and other factors -increased plasma carbon dioxide levels
sensory input from receptors in joints, neural input from the motor cortex, and other factors Correct Yes, at the beginning of exercise, blood gases have not changed; thus, other factors such as anticipation of exercise contribute to the increase in respiration.
Which of the following behaviors would most likely result in an increased alveolar ventilation rate as compared to that of normal breathing? -breathing rapidly into a paper bag -breathing slowly into a paper bag -rapid shallow breathing -slow deep breathing
slow deep breathing Correct 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.
During inhalation, -the diaphragm and rib muscles contract -the diaphragm relaxes -the volume of the thoracic cavity decreases -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 Correct The contraction of these muscles causes air to enter the lungs.
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 response is correct
the intrapleural pressure would not decrease normally during inhalation Correct 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.
Internal and external respiration depends on several factors. Which of the following is NOT an important factor in gas exchange? -the molecular weight of the gas -available surface area -partial pressure of the gases -rate of blood flow through the tissue
the molecular weight of the gas Correct Yes, molecular weight is not an important factor in gas exchange.
Which volumes are combined to provide the inspiratory capacity? -expiratory reserve volume (ERV) and residual volume (RV) -tidal volume (TV), inspiratory reserve volume (IRV), and expiratory reserve volume (ERV) -tidal volume (TV), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), and residual volume (RV) -tidal volume (TV) and inspiratory reserve volume (IRV)
tidal volume (TV) and inspiratory reserve volume (IRV) Correct The inspiratory capacity, which is the total amount of air that can be taken into the lungs after a normal relaxed exhalation, is equal to the tidal volume (TV) plus inspiratory reserve volume (IRV).
Using the same graph as in Part A, what is the average number of oxygens bound to hemoglobin at a saturation of 50%? -two -three -four -one
two Correct Binding of oxygen to an individual hemoglobin protein occurs at one oxygen per hemoglobin representing 25% saturation; two oxygens per hemoglobin, 50%; three oxygens per hemoglobin, 75%; and four oxygens per hemoglobin, 100% saturation. If an average of two oxygens are bound in all hemoglobins collectively, there is 50% saturation, shown at a blood PO2PO2 of 25 mm of Hg.
What area in the brain sets the respiratory rhythm? -pontine respiratory group (PRG) -dorsal respiratory group (DRG) -ventral respiratory group (VRG) -hypothalamus
ventral respiratory group (VRG) Correct Yes, the VRG is the rhythm-generating center in the medulla.
Which of these cells would be most effective in the disposal of inspired microorganisms that may enter the alveoli? -alveolar macrophages -type I alveolar cells -lymphocytes in blood circulating through the lungs -type II alveolar cells
-alveolar macrophages Correct Alveolar macrophages wander freely, ingesting and destroying invading microorganisms or foreign matter.
Using the spirographic data shown, what is the minute ventilation of an average adult male at rest breathing at a rate of 10 breaths per minute? 5000 milliliters per minute 36000 milliliters per minute 48000 milliliters per minute 60000 milliliters per minute
5000 milliliters per minute Correct The minute ventilation is calculated by multiplying the breaths per minute by the tidal volume, so in this case, 10 breaths/minute × 500 ml/breath = 5000 ml/minute.
Which statement is correct? -Oxygen is released from the mitochondria as a product of cellular respiration. -Carbon dioxide diffuses from the alveoli into surrounding capillaries. In the blood, oxygen is bound to hemoglobin, a protein found in red blood cells. -As oxygen diffuses from the lungs into capillaries, blood becomes deoxygenated. -Oxygen diffuses from large blood vessels into the body's cells.
In the blood, oxygen is bound to hemoglobin, a protein found in red blood cells. Correct When oxygen diffuses from the alveoli to the surrounding capillaries, it enters a red blood cell and binds to hemoglobin.
After blood becomes oxygenated. -it does not return to the heart, but goes directly to the lungs. -it returns to the heart, and is then pumped to the lungs. it does not return to the heart, but goes directly to capillaries that supply the body's cells with oxygen. -it does not return to the heart, but goes to the nose and mouth. -it returns to the heart, and is then pumped to body cells.
It returns to the heart, and is then pumped to body cells
Focus your attention again on Focus Figure 22.1. Focus Figure 22.1. A firefighter breathes in air normally as he enters a building following an explosion and fire. He has a meter that predicts the PO2PO2 will approximate 15 mm Hg in his tissue fluids as he actively moves about the room. Select the best statement. -The large changes in PO2 tissue environments cause only very small changes in hemoglobin O2 saturation, and no oxygen is needed. -The firefighter is at about 10% hemoglobin O2O2 saturation, and he requires an external air tank. -The firefighter's hemoglobin saturation will be about one oxygen per hemoglobin, and he will require an external air tank. -The S-shaped saturation curve of hemoglobin is flat at this PO2PO2, and O2O2 saturation doesn't change much with PO2PO2 changes in mm Hg.
The firefighter's hemoglobin saturation will be about one oxygen per hemoglobin, and he will require an external air tank. Correct An O2O2 saturation of hemoglobin of ~25% is insufficient for the firefighter moving about the room, and he should use external oxygen.
From which structures do oxygen molecules move from the lungs to the blood? -alveoli =bronchioles -bronchi -nose -trachea
alveoli Correct Alveoli are tiny sacs in the lungs surrounded by capillaries. The alveoli are where oxygen diffuses from the lungs to the blood.
Which of the following would induce the loss of oxygen from the hemoglobin and the blood? -decreases in plasma carbon dioxide -a drop in blood pH increase in hemoglobin that has -oxygen bound to it already -a decrease in blood temperature
a drop in blood pH Correct 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.
Which of the following is/are part(s) of the respiratory zone structures? -alveoli -terminal bronchioles -trachea -primary bronchi
alveoli Correct Alveoli are thin-walled air sacs that are the sites of gas exchange. Along with the respiratory bronchioles and alveolar ducts, the alveoli make up the respiratory zone.
