Respiratory System

[CO2] = H PCO2 H = 3.4 x 10^-2 mol/L*atm PCO2 = 1 atm * 0.21 = 0.21 atm [CO2] = 3.4 x 10^-2 mol/L*atm 0.21 atm [CO2] = 3.4 x 10^-2 mol/L*atm * 0.21 atm [CO2] = 0.007 mol/L

A cup of water is sitting on a table at room temperature in an atmosphere that contains 21% CO2. How much CO2 will be found in the cup of water? (H(CO2) = 3.4 x 10^-2 mol/L*atm)

PCO2 = Kh [CO2] PCO2 = 1 atm * 0.21 = 0.21 atm Kh = 29 L*atm/mol 0.21 atm = 29 L*atm/mol [CO2] 0.21 atm*mol = [CO2] 29 L*atm [CO2] = 0.007 mol/L

A cup of water is sitting on a table at room temperature in an atmosphere that contains 21% CO2. How much CO2 will be found in the cup of water? (Kh(CO2) = 29 L*atm/mol)

[O2] = H P(O2) H = 1.3 x 10^-3 mol/L*atm P(O2) = 1 atm * 0.21 = 0.21 atm [O2] = 1.3 x 10^-3 mol/L*atm 0.21 atm [O2] = 1.3 x 10^-3 mol/L*atm * 0.21 atm [O2] = 2.7 x 10^-4 mol/L

A cup of water is sitting on a table at room temperature. The air around the cup consists of 21% O2. How much oxygen will be found in the cup of water? (H(O2) = 1.3 x 10^-3 mol/L*atm)

P(O2) = Kh [O2] P(O2) = 1 atm * 0.21 = 0.21 atm Kh = 770 L*atm/mol 1 atm * 0.21 = 770 L*atm/mol [O2] 0.21 atm = 770 L*atm/mol [O2] 0.21 atm * mol = [O2] 770 L * atm [O2] = 2.7 x 10^-4 mol/L

A cup of water is sitting on a table at room temperature. The air around the cup consists of 21% O2. How much oxygen will be found in the cup of water? (Kh(O2) = 770 L*atm/mol)

Answer: B. The intrapleural space, bounded by the parietal and visceral pleurae, is a potential space. As such, it is normally collapsed and contains a small amount of fluid. However, introduction of fluid or air into the intrapleural space can fill the space, causing collapse of the lung. The other options listed are too firmly apposed to permit blood to collect in these spaces.

A patient presents to the emergency room with a stab wound to the left side of the chest. On a chest x-ray, blood is noted to be collecting in the chest cavity, causing collapse of both lobes of the left lung. The blood is most likely located between the: A. the parietal pleura and the chest wall B. the parietal pleura and the visceral pleura C. the visceral pleura and the lung D. the alveolar walls and the lung surface

Answer: C. When a patient with an asthma attack does not respond to treatment and has been hyperventilating for over an hour, he or she may become fatigued and may not be able to maintain hyperventilation. In this case, the patient begins to decrease his or her breathing rate and is not receiving adequate oxygen. By extension, carbon dioxide is trapped in the blood, and the pH begins to drop. Despite the fact that this pH is normal at the moment, this patient is crashing and may start demonstrating acidemia in the near future. While the kidneys should compensate for alkalemia, this is a slow process and would not normalize blood pH within an hour; further, adequate compensation by the kidneys would actually be a reassuring sign, eliminating (A). There is no evidence to suggest that the measurement was inaccurate, eliminating (B). Finally, after treatment, the patient should return to a normal blood pH with adequate ventilation and would not be expected to overcompensate by becoming acidemic, eliminating (D).

A patient presents to the emergency room with an asthma attack. The patient has been hyperventilating for the past hour and has a blood pH of 7.52. The patient is given treatment and does not appear to respond, but a subsequent blood pH reading is 7.41. Why might this normal blood pH not be a reassuring sign? A. The patient's kidney's may have compensated for the alkalemia B. The normal blood pH reading is likely inaccurate C. The patient may be descending into respiratory arrest D. The patient's blood should ideally become acidemic for some time to compensate for the alkalemia

Answer: D. Gas exchange in the lungs relies on passive diffusion of oxygen and carbon dioxide. This is accomplished easily because there is always a difference in the partial pressures of these two gases and because the subdivision of the respiratory tree creates a large surface area of interaction between the alveoli and the circulatory system. In addition, the thin alveolar walls allow for fast diffusion and gas exchange. Therefore, (A), (B), and (C) can be eliminated. (D) is the correct answer because active transport is not used in the gas exchange process in the lungs.

All of the following facilitate gas exchange in the lungs except: A. thin alveolar walls B. multiple subdivisions of the respiratory tree C. differences in the partial pressures of O2 and CO2 D. active transporters in alveolar cells.

Answer: C. Allergic reactions occur when a substance binds to an antibody and promotes an overactive immune response with inflammatory chemicals. The antibody is already attached to the mast cell. Thus, when the substance binds to the antibody, the mast cell can release the inflammatory mediators that cause allergic reactions.

Allergic reactions occur due to an overactive immune response to a substance. Which cells within the respiratory tract play the largest role in the generation of allergic reactions? A. Alveolar epithelial cells B. Macrophages C. Mast cells D. Ciliated epithelial cells

-Thermoregulation -Immune Functions -Control Blood pH

Aside from gas exchange, what are the other functions that the respiratory system can perform?

The pressure differentials between the alveoli and the blood drives the exchange of CO2 and O2 down their concentration gradients. The alveoli has a high pO2 and a low pCO2, while the deoxygenated blood flowing into the pulmonary capillaries has a high pCO2 and a low pO2. This will cause the gas molecules to diffuse to areas of lower concentration, causing CO2 to flow into the alveoli and O2 to flow into the pulmonary capillaries.

Describe the driving forces that dictate gas exchange in the lungs.

Mucus that lines the internal airways traps particulate matter and larger invaders. Underlying cilia propels mucus up the respiratory tract to the oral cavity where it can be expelled or swallowed.

Describe the immune functions of the mucocillary escalator in the internal airways.

1. Air enters through the nasal or oral cavity of the nose or mouth respectively. 2. Air flows through the pharynx and is directed into the larynx by the epiglottis. 3. Air flows through the trachea and bronchi, and enters the lungs. 4. In the lungs, air travels through the branching bronchioles until they reach the alveoli, where gas exchange with the blood takes place in.

Describe the pathway of air flowing into the lungs.

1. O2 dissociates from air in the alveolus and enters the layer of fluid that coats the inside of the alveolus. 2. Oxygen moves through the epithelial cells and through the basement membrane. 3. The oxygen exits the basement membrane of the alveolus and moves through a layer of connective tissue that separates the alveolus and the pulmonary capillaries. 4. Oxygen enters the basement membrane of the capillary, passes through the endothelial cells, and enters the bloodstream. 5. Oxygen moves through the plasma, and binds to hemoglobin in the RBC.

Describe the pathway of oxygen as it moves from the

Mouth/nasal cavity ---> Pharynx ---> Larynx ---> Trachea ---> Bronchi ---> Bronchioles ---> Alveoli

Describe the pathway that air travels towards the lungs.

1. The external intercostal muscles and diaphragm relax, causing the alveoli to recoil due to the elastic potential energy generated by the elastin proteins in the alveoli. 2. This leads to the intrapleural space to constrict, which causes the lungs to constrict as well, resulting in the volume of the lungs decreases back to original volume. 2. Pressure in the lungs increases in lungs due to change in volume, as a result of the decrease in volume. Lungs exhibit positive pressure relative to atmospheric pressure. 3. Air molecules move out of the lungs. 4. Pressure in lungs equilibrates with atmospheric pressure, as a result of air molecules moving out, resulting in a decrease in pressure in the lungs.

Describe the process of exhalation in the lungs.

1. External intercostal muscles and diaphragm contract, causing the thorax to expand, which increases the intrapleural space surrounding the lungs. 2. As a result of the intrapleural space increasing, the alveoli in the lungs will expand as well, increasing the volume of the lungs in the process. 3. Pressure in the lungs decreases slightly due to volume increase. Lungs exhibit negative pressure relative to atmospheric pressure. 4. Air molecules move into the lungs 5. Pressure in the lungs equilibrates with atmospheric pressure, as a result of air molecules moving in, resulting in an increase in pressure in the lungs.

Describe the process of inhalation in the lungs.

They are two cords found in the larynx that are maneuvered using skeletal muscle and cartilage.

Describe the vocal cords.

No. Since the force that drives gas exchange are pressure differentials between the alveoli and the capillaries, it does not require ATP.

Does gas exchange require any energy to pull off?

Answer: C. The pharynx, which lies behind the nasal cavity and oral cavity, is a common pathway for food entering the digestive system and air entering the respiratorysystem. It is the larynx that contains the vocal cords, not the pharynx.

Each of the following statements regarding the anatomy of the respiratory system is true except: A. the epiglottis covers the glottis during swallowing to ensure that food does not enter the trachea B. the trachea and bronchi are lined by ciliated epithelial cells C. the pharynx contains two vocal cords, which are controlled by skeletal muscle and cartilage D. the nares are lined with vibrissae, which helps filter out particulate matter from inhaled air

-Decrease thickness of membrane -Use smaller molecules instead of large molecules -Increase the concentration of molecules used -Increase surface area of membrane

How can one maximize the diffusion rate of a molecules across a semipermeable barrier?

Hyperventilation is the increase in air movement into the lungs, which increases the delivery or O2 into the blood and increases the release of CO2 from the body. This results in hyperoxia, or the increase in O2 levels in the blood, which in turn increases the pH in the blood, termed alkalinemia.

How does hyperventilation affect the blood in the circulatory system?

Hypoventilation is the decrease in air movement into the lungs, which decreases the delivery of O2 into the blood and decreases the release of CO2 from the body. This results in hypercapnia/hypercarbia, or the increase in CO2 levels in the blood, which in turn decreases the pH of the blood, termed acidemia.

How does hypoventilation affect the blood in the circulatory system?

When the blood pH is high, it means that there is an excess of O2 in the blood, meaning the bicarbonate buffer system shifts to the left. To compensate for this, the respiratory center will shift the bicarbonate buffer system more to the right by decreasing respiratory rate of the lungs, decreasing the intake of O2.

How does the respiratory system respond to high blood pH levels (alkalemia)?

When the blood pH is low, it means that there is an excess of CO2 in the blood, meaning the bicarbonate buffer system shifts to the right. To compensate for this, the respiratory center will shift the bicarbonate buffer system more to the left by increasing respiratory rate of the lungs, expelling the excess CO2.

How does the respiratory system respond to low blood pH levels (acidemia)?

During active tasks, exhalation is sped up through the contraction of internal intercostal muscles and abdominal muscles, which pulls the rib cage down. This causes the thoracic cavity to actively decrease in volume, meaning it requires ATP to exhale like this.

How is exhalation sped up when performing active tasks?

D = Pa/Kh sqrt(MW) Pa = partial pressure Kh = Henry's volatility constant MW = molecular weight D = diffusion constant

How is the diffusion constant of Fick's Law of Diffusion calculated?

1. We would breathe more rapidly to avoid hypoxia. 2. The binding dynamics of hemoglobin to oxygen would be altered in order to facilitate the unloading of oxygen at the tissues.

How would our respiratory systems adjust if we moved to higher altitudes where less oxygen is available?

A. Total Lung Capacity (TLC) B. Tidal Volume (TV) C. Vital Capacity (VC) D. Residual Volume (RV) E. Inspiratory Reserve Volume (IRV) F. Expiratory Reserve Volume (ERV)

Identify the different lung volumes shown on the chart here.

A. Nasal cavity B. Oral cavity C. Pharynx D. Epiglottis E. Larynx F. Trachea G. Left lung H. Pulmonary blood vessels I. Heart J. Left upper lobe K. Left lower lobe L. Right lung M. Right upper lobe N. Right middle lobe O. Right lower lobe

Identify the labeled structures of the respiratory system.

Answer: B. In a patient with IPF, the increased stiffness of the lungs would likely decrease the volume of air the individual could inhale, which would decrease both the total lung capacity and inspiratory reserve volume. However, spirometry cannot measure the total lung capacity accurately because it cannot determine the residual volume - the volume of air left in the lungs when an individual has maximally exhaled. Because the residual volume makes up a portion of the total lung capacity (total lung capacity = vital capacity + residual volume), a spirometer cannot be used to determine the total lung capacity. Therefore, while statement I is a true statement about individuals with IPF, it cannot appear in the answer choice. Finally, increased stiffness of the lungs would be expected to decrease the residual volume, not increase it; further, residual volume, as described above, cannot be measured with a spirometer.

Idiopathic pulmonary fibrosis (IPF) is a disease in which scar tissue forms in the alveolar walls, making the lung tissue significantly more stiff. Which of the following findings would likely be detected through a spirometry in a patient: I. Decreased total lung capacity II. Decreased inspiratory reserve volume III. Increased residual volume A. I only B. II only C. I and II only D. I, II, and III

When CO2 levels become too low, the brain can decrease the respiratory rate in order to raise CO2 levels.

If blood levels of CO2 become too low, how does the brain alter the respiratory rate to maintain homeostasis?

Volatility: How willing a substance is to vaporize into the air Solubility: How willing a substance is to dissolve into a solution

In chemistry, what does volatility refer to? What about solubility?

Answer: A. The intrinsic elastic properties of the lung are important during exhalation as the passive recoil of lung tissue helps decrease lung volume. With decreased recoil, the patient will have difficulty exhaling completely, increasing the residual volume. The total lung capacity would be expected to increase in this case because there would be less recoil opposing inhalation, eliminating (B). With decreased alveolar surface area, one would expect decreased gas exchange, which would decrease blood concentrations of oxygen while increasing blood concentrations of CO2, eliminating (C) and (D).

In emphysema, the alveolar walls are destroyed, decreasing the recoil of the lung tissue. Which of the following changes may be seen in a patient with emphysema? A. Increased residual volume B. Decreased total lung capacity C. Increased blood concentration of oxygen D. Decreased blood concentration of carbon dioxide

C3-C5: Diaphragm muscle T1-T11: Intercostal muscles (Each nerve goes to a different intercostal muscle) T6-L1: Abdominal muscles C1-C3: Accessory muscles (muscles around the neck area)

Match the following motor nerves of the spinal column with the muscle group they control in the respiratory system: Motor nerves -C3-C5 -T1-T11 -T6-L1 -C1-C3 Muscle groups -Abdominal muscles -Diaphragm muscle -Accessory muscles (muscles around neck area) -Intercostal muscles

-Macrophages engulf and digest pathogens and signals the rest of the immune system of the pathogen's presence. -Mucosal surfaces contains IgA antibodies that protect against pathogens. -Mast cells releases inflammatory chemicals into the surrounding area when the right substances bind to antibodies, which promotes an immune response.

Name and describe the immune cells that are found in the lungs.

Answer: A. This question requires a few different levels of thinking. The question stem states that premature infants often require ventilation using positive end-expiratory pressures. At the end of expiration, the ventilator will provide a higher pressure than normal, which forces extra air into the alveoli. This pressure must be used to prevent alveolar collapse, which should remind you that surfactant serves the same purpose by reducing surface tension. Thus, it makes sense that if premature babies lack surfactant, providing extra air pressure at the end of expiration would be beneficial.

Premature infants with respiratory distress are often put on ventilators. Often, the ventilators are set to provide positive end-expiratory pressure. Why might this setting be useful for a premature infant? A. Premature infants lack surfactant B. Premature infants lack lysozymes C. Premature infants cannot thermoregulate D. Premature infants are unable to control pH

In respiratory failure, ventilation slows, and less carbon dioxide is blown off. As this occurs, the buffer equation shifts to the right, and more hydrogen ions are generated. This results in a lower pH of the blood.

Respiratory failure refers to inadequate ventilation to provide oxygen to the tissues. How would the pH change in respiratory failure?

Answer: D. If an area of the lung becomes filled with mucus and inflammatory cells, the area will not be able to participate in gas exchange. Because no air will enter or leave the area, the concentration gradient will no longer exist, and neither oxygen nor carbon dioxide will be able to diffuse across the alveolar wall.

Some forms of pneumonia cause an excess of fluids such as mucus or pus to build up within an entire lobe of the lung. How will this affect the diffusion of gases within the affected area? A. Carbon dioxide can diffuse out, but oxygen will not be able to enter the blood B. Oxygen can diffuse into the blood, but carbon dioxide cannot diffuse out C. No change in diffusion will occur D. No diffusion will occur in the affected area

Answer: B. When people hyperventilate, their respiratory rate increases. When the respiratory rate increases, more CO2 is blown off. This causes a shift to the left in the bicarbonate buffer equation, and the blood becomes more alkaline. Breathing into the paper bag allows some of this CO2 to be returned to the bloodstream in order to maintain proper pH.

Some people with anxiety disorders respond to stress by hyperventilating. It is recommended that these people breathe into a paper bag and then rebreathe this air. Why is this treatment appropriate? A. Hyperventilation causes an increase in blood CO2, and breathing the air in the bag helps readjust blood levels of CO2 B. Hyperventilation causes a decrease in blood CO2, and breathing the air in the bag helps readjust blood levels of CO2 C. Hyperventilation causes an increase in blood O2, and breathing the air in the bag helps to readjust blood levels of O2 D. Hyperventilation causes a decrease in blood O2, and breathing the air in the bag helps to readjust blood levels of O2

Answer: B. Lysozyme is an enzyme present in the nasal cavity, saliva, and tears that degrades peptidoglycan, preventing infection by gram-positive bacteria. Thus premature infants who lack lysozymes are more likely to suffer from infections with these organisms.

Studies have indicated that premature babies are often deficient in lysozyme. What is a possible consequence of this deficiency? A. Respiratory distress and alveolar collapse shortly after birth B. Increased susceptibility to certain infections C. Inability to humidify air as it passes through the nasal cavity D. Slowing of the respiratory rate in response to acidemia

conducting zone and respiratory zone

The _______________________ zone the series of tubes in which air travels in order to reach the lungs, while the _________________________ zone is the part of the respiratory system that directly participates in gas exchange

Glottis

The ________________________ is the opening of the larynx.

Answer: B. During inhalation, the chest cavity expands, causing expansion of the intrapleural space. According to Boyle's law, an increase in volume at a constant temperature is accompanied by a decrease in pressure. When the intrapleural pressure (and, by extension, the alveolar pressure) is less than atmospheric pressure, air enters the lungs. During exhalation, these pressure gradients reverse; thus, during exhalation, intrapleural pressure is higher than atmospheric pressure, not lower.

The intrapleural pressure is necessarily lower than atmospheric pressure during: A. inhalation, because the expansion of the chest cavity causes compression of the intrapleural space, decreasing its pressure. B. inhalation, because the expansion of the chest cavity causes expansion of the intrapleural space, decreasing its pressure. C. exhalation, because the compression of the chest cavity causes compression of the intrapleural space, decreasing its pressure. D. exhalation, because the compression of the chest cavity causes expansion of the intrapleural space, decreasing its pressure.

Answer: C. Total lung capacity is equal to the vital capacity (the maximum volume of air that can be forcibly inhaled and exhaled from the lungs) plus the residual volume (the air that always remains in the lungs, preventing the alveoli from collapsing).

Total lung capacity is equal to the vital capacity plus the: A. tidal volume B. expiratory reserve volume C. residual volume D. inspiratory reserve volume

Intercostal muscles and diaphragm relax Alveoli recoils

What are the actions of the intercostal muscles, diaphragm, and alveoli during exhalation?

Intercostal muscles and diaphragm contract Alveoli expands

What are the actions of the intercostal muscles, diaphragm, and alveoli during inhalation?

The left lung has two lobes (an upper and lower lobe) and the right lung has three lobes (an upper, middle, and lower lobe. The left lung has a cardiac notch that makes more room for the heart, while the right lung lacks this notch.

What are the differences between the left lung and the right lung?

[C]/P = H P/[C] = Kh Pg = partial pressure of gas in air [C]g = concentration of gas in solution H = Henry's solubility constant K(H) = Henry's volatility constant

What are the equations that explains Henry's Law?

-Vibrissae in the nasal cavity -Lysozyme in the nasal cavity -The mucocillary escalator in the internal air ways -Immune cells in the lungs

What are the immune functions of the respiratory system?

Short-term: increase production of RBCs to ensure proper delivery of O2. Long-term: development of more blood vessels (vascularization) to facilitate distributions of O2 to tissues.

What are the short-term and long-term changes that occur when living at higher altitudes for extended periods of time?

aortic bodies and carotid bodies

What are the two major types of peripheral chemoreceptors?

The pleurae The visceral pleura is the inner layer that is adjacent to the lungs The parietal pleura is the outer layer.

What are the two membranes that surround the lungs? Where are they located in relation to the lungs?

Vibrissae are small hairs in the nasal cavity that trap particulate matter and potentially infectious diseases.

What are vibrissae, and what immune functions do they serve?

Fi(O2) x (P(ATM)-P(H2O)) represents the amount of oxygen that enters the alveoli when inhaling. (PA(CO2)/RQ) represents the amount of oxygen that exits the alveoli through gas exchange.

What do the two components of the alveolar gas equation represents?

The rate of diffusion of molecules will increase if difference in pressure increases, surface area of barrier increases, diffusion constant increases, and thickness of barrier decreases.

What does Fick's Law state

The effusion or diffusion rate of a gas is inversely proportional to the square root of the gas's molar mass.

What does Graham's Law state?

At constant temperature, the partial pressure of a gas is directly related to its solubility in a liquid.

What does Henry's Law state?

It tells us how much oxygen is found in the alveolar sac.

What does the alveolar gas equation tell us?

-Changes in Fi(O2) (percentage of O2 found in the air inhaled) like using an oxygen mask will increase the percentage of O2 you breathe in, which increases Fi(O2). -Changes in P(ATM) (atmospheric pressure) like if you are at sea level or up on a mountain, P(ATM) would decrease the higher the elevation you are. -Changes in Pa(O2) (partial pressure in the alveolus) which can be affected by changes in Fi(O2) or P(ATM). -Changes in A (surface area of alveoli) where alveoli that stopped functioning in the lungs cause a decrease in surface area, which leads to a decrease in A. -Changes in T (thickness of layers between the alveoli and the capillary) where a decrease in thickness leads to an increase in the diffusion of oxygen.

What factors would affect the rate of diffusion of oxygen from the alveoli to the pulmonary capillary?

It is a tool that allows for various measurements of volume in the lungs to be made.

What is a spirometer?

It is an enzyme found in tears, saliva, and nasal mucus that attacks peptidoglycan walls of gram-positive bacteria.

What is lysozyme, and what immune functions do they serve?

The pharynx

What is the common pathway that the respiratory system and the digestive system share?

V = ΔP * A * D T ΔP = difference in pressure across the barrier A = Surface Area of the barrier D = Diffusion constant (can be obtained using Henry's Law and Graham's Law) T = Thickness of barrier V = Rate of Diffusion across a barrier

What is the equation that explains Fick's Law of Diffusion?

Rate1 = sqrt(MW2) Rate2 sqrt(MW1) MW = molecular weight Rate = effusion or diffusion rate

What is the equation that explains Graham's Law?

PA(O2) = Fi(O2) x (P(ATM)-P(H2O)) - (PA(CO2)/RQ) PA(O2) = Partial pressure of O2 in the alveoli Fi(O2) = Fraction of inspired oxygen (percentage of oxygen in the air breathed in) P(ATM) = Atmospheric pressure (760 mmHg) P(H2O) = Partial pressure of H2O in the lungs PA(CO2) = Partial pressure of CO2 in the alveoli RQ = Respiratory Quotient

What is the equation that explains the alveolar gas equation?

VC = IRV + TV + ERV

What is the mathematical relationship between vital capacity (VC), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), and tidal volume (TV)?

Surfacant is a detergent that coats the alveoli that lowers the surface tension of it to prevent the lungs from collapsing in on itself.

What is the purpose of surfacant?

It is the space in the chest that houses the heart and lungs. The ribs, the diaphragm, and the intercostal muscles are what makes up the thorax.

What is the thorax? What structures make up the thorax?

1 atm 760 mmHg

What is the value of atmospheric pressure (in both atm and mmHg)?

The cerebrum is responsible for voluntary actions involving the respiratory system, such as singing, yelling, or just talking.

What role does the cerebrum have on respiration?

It signals the respiratory center to adjust breathing rate in response to a certain emotion (such as rapid breathing during fear and anxiety).

What role does the hypothalamus have on respiration?

Changes in CO2 and pH levels in the blood. O2 levels.

What type of signals are central chemoreceptors sensitive to? What signal related to the respiratory system do central chemoreceptors not pick up on?

Increases Decreases

When air pressure increases, the number of collisions of air particles _______________________. Likewise, when air pressure decreases, the number of collisions of air particles ________________________.

Larynx

Where are the vocal chords located in the body?

Mechanoreceptors in the nose, lungs, and GI tract. Mechanoreceptors in the lungs and GI tract travel through the vagus nerve (Cranial nerve 10) Mechanoreceptors in the nose travels through the trigeminal nerve (Cranial nerve 5)

Where in the body can you find mechanoreceptors that sends signals to the respiratory center? What nerves do these mechanoreceptors travel through?

O2 moves from the alveoli to the blood in the pulmonary capillaries, while CO2 is moved from the pulmonary capillaries to the alveoli.

Which gases are exchanged during gas exchange in the lungs?

CO2

Which molecule is more soluble in blood: O2 or CO2?

The vagus nerve (Cranial nerve 10)

Which nerve do aortic bodies travel through in order to reach the respiratory center?

The glossopharyngeal nerve (Cranial nerve 10)

Which nerve do carotid bodies travel through in order to reach the respiratory center?

Answer: D. The molecules involved in ventilation are the diaphragm, which separates the thoracic cavity from the abdominal cavity, and the intercostal muscles. During inhalation, the diaphragm contracts and flattens, while the external intercostal muscles contract, pulling the rib cage up and out. These actions cause an overall increase in the volume of the thoracic cavity. During exhalation, both the diaphragm and the external intercostals relax, causing a decrease in the volume of the thoracic cavity because of the recoil of these tissues. In forced exhalation, the internal intercostals and abdominal muscles may contract to force out air. Thus, the only correct association from the given answers is (D).

Which of the following associations correctly pairs a stage of respiration with the muscle actions occurring during that stage? A. Inhalation - diaphragm relaxes B. Inhalation - internal intercostal muscles contract C. Exhalation - diaphragm contracts D. Exhalation - external intercostal muscles relax

Answer: D. Air enters the respiratory tract through the external nares (nostrils) and travels through the nasal cavities. It then passes through the pharynx and into the larynx. Ingested food also passes through the pharynx on its way to the esophagus; to ensure that food does not accidentally enter the larynx, the epiglottis covers the larynx during swallowing. After the larynx, air goes into the trachea, which eventually divides into two bronchi, one for each lung. Bronchi branch into smaller bronchioles, which terminate in clusters of alveoli. From the given sequences, only (D) correctly describes the sequence of the passages through which air travels.

Which of the following is a correct sequence of passageways through which air travels during inhalation? A. Pharynx --> trachea --> bronchioles --> bronchi --> alveoli B. Pharynx --> trachea --> larynx --> bronchi --> alveoli C. Larynx --> pharynx --> trachea --> bronchi --> alveoli D. Pharynx --> larynx --> trachea --> bronchi --> alveoli

nose, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles

Which structures are considered part of the conducting zone?

respiratory bronchioles and alveoli

Which structures are considered part of the respiratory zone?

Inhalation is driven by the contraction of intercostal muscles and diaphragm, which requires ATP for energy to move those muscles. Exhalation is driven by the elastic potential energy generated by the elastin proteins in the alveoli, which does not require ATP to pull off. In conclusion, inhalation is considered an active process because it requires ATP, while exhalation is considered a passive process because it doe not require ATP.

Why is inhalation considered an active process but not exhalation?

peripheral chemoreceptors

__________________ are receptors located in the PNS that are somewhat sensitive to CO2 and pH but are most sensitive to the level of oxygen in the arterial blood; they relay these signals to the respiratory center in order to regulate breathing

Residual volume (RV)

___________________ is the measurement of the volume of air remaining in the lungs when one exhales completely (minimum volume of air in the lungs).

Total lung capacity (TLC)

____________________ is the measurement of the maximum volume of air in the lungs when one inhales completely.

central chemoreceptors

_____________________ are receptors located in the medulla oblongata that are sensitive to changes in carbon dioxide and pH levels in the blood, and relays this information to the respiratory center to regulate breathing rate.

Respiratory center

_____________________ is the collection of two areas of medulla oblongata that coordinate with one another to regulate breathing rate.

Expiratory reserve volume (ERV)

_____________________ is the measurement of the volume of additional air that can be forcibly exhaled after a normal exhalation.

Baroreceptors

________________________ are mechanoreceptors in blood vessels that detects changes in blood pressure.

Vital capacity (VC)

________________________ is the measurement of the difference between the total volume of the lungs and the residual volume of the lungs.

Inspiratory reserve volume (IRV)

________________________ is the measurement of the volume of additional air that can be forcibly inhaled after a normal inhalation.

Tidal volume (TV)

_________________________ is the measurement of the volume of air inhaled and exhaled in a normal breath.