1.
Surfactant
Correct Answer
A. Helps prevent the alveoli from collapsing
Explanation
Surfactant is a substance that is found in healthy lung tissue and plays a crucial role in preventing the alveoli from collapsing. The alveoli are tiny air sacs in the lungs where gas exchange occurs. Without surfactant, the surface tension in the alveoli would be too high, causing them to collapse and making it difficult for oxygen to be absorbed into the bloodstream. Therefore, surfactant helps to reduce surface tension and keep the alveoli open, allowing for efficient gas exchange and proper lung function.
2.
Functions of the nasal cavity include all of the following, except:
Correct Answer
B. Acting as a reservoir during coughing
Explanation
The nasal cavity performs several functions, including humidifying, warming, and filtering the air that enters the respiratory system. It also acts as a resonating chamber during speech, helping to modify the sound produced. However, it does not serve as a reservoir during coughing. Coughing is a reflex action that helps to clear the airways of irritants or foreign particles, and the nasal cavity is not directly involved in this process.
3.
The portion of hte pharynx that receives both air and food is the
Correct Answer
A. Oropharynx
Explanation
The oropharynx is the portion of the pharynx that receives both air and food. It is located behind the oral cavity and extends from the soft palate to the epiglottis. The oropharynx plays a crucial role in the digestive and respiratory systems as it serves as a passageway for both food and air. It is also involved in the process of swallowing, as it helps direct food towards the esophagus and prevents it from entering the larynx and trachea.
4.
The glottis is
Correct Answer
B. The opening to the larynx
Explanation
The glottis refers to the opening to the larynx. It is the space between the vocal cords where air passes through during breathing. The larynx is responsible for producing sound and protecting the airway during swallowing. The glottis plays a crucial role in vocalization and respiration.
5.
The elastic cartilage that shields the opening to the larynx during swallowing is the ______ cartilage.
Correct Answer
E. Epiglottic
Explanation
The elastic cartilage that shields the opening to the larynx during swallowing is the epiglottic cartilage. This cartilage is located at the base of the tongue and prevents food and liquid from entering the airway by covering the opening to the larynx. It is flexible and capable of bending to allow for the passage of air during breathing and closing off the airway during swallowing to protect the lungs from aspiration. The other options listed are different types of cartilage found in the larynx, but they do not specifically serve the function of shielding the opening during swallowing.
6.
The cartliage that articulates with the superior border of the enlarged portion of hte cricoid cartilage is the ______ cartilage.
Correct Answer
D. Arytenoid
Explanation
The cartilage that articulates with the superior border of the enlarged portion of the cricoid cartilage is the arytenoid cartilage.
7.
A pair of ligaments in the larynx that are covered by epithelium and function in sound production are
Correct Answer
C. Vocal folds
Explanation
The correct answer is vocal folds. The vocal folds, also known as vocal cords, are a pair of ligaments located in the larynx. They are covered by epithelium and play a crucial role in sound production. When air passes through the larynx, the vocal folds vibrate, producing sound. The tension and position of the vocal folds can be adjusted to produce different pitches and tones, allowing us to speak and sing.
8.
The following is a list of some of the structures of the respiratory tree
1. secondary bronchi
2. bronchioles
3. alveolar ducts
4. primary bronchi
5. respiratory bronchioles
6. alveoli
7. terminal bronchioles
The order in which air passes through these structures is:
Correct Answer
C. 4 1 2 7 5 3 6
9.
The respiratory membrane consists primarily of
Correct Answer
A. Simple squamous epithelium
Explanation
The correct answer is simple squamous epithelium. The respiratory membrane is responsible for gas exchange in the lungs, and it consists of a very thin layer of cells. Simple squamous epithelium is the ideal type of tissue for this function because it is composed of a single layer of flattened cells, allowing for efficient diffusion of gases across the membrane. This type of epithelium is also found in other areas involved in gas exchange, such as the walls of capillaries.
10.
The actual sites of gas exchange within the lungs are
Correct Answer
A. Alveoli
Explanation
The alveoli are tiny air sacs located at the end of the bronchioles in the lungs. They are the primary sites of gas exchange, where oxygen from inhaled air diffuses into the bloodstream and carbon dioxide, a waste product, is removed from the bloodstream and exhaled. The alveoli have thin walls and a large surface area, allowing for efficient exchange of gases between the air and the blood.
11.
Boyle's law states that gas volume is
Correct Answer
C. Indirectly proportional to pressure
Explanation
Boyle's law states that the volume of a gas is inversely proportional to its pressure. This means that as the pressure of a gas increases, its volume decreases, and vice versa. This relationship is described by the equation P1V1 = P2V2, where P1 and V1 are the initial pressure and volume, and P2 and V2 are the final pressure and volume. Therefore, the correct answer is "indirectly proportional to pressure."
12.
Each of the following muslces can elevate the ribs, except:
Correct Answer
A. External oblique
Explanation
The external oblique muscle is not involved in elevating the ribs. The scalenes, sternocleidomastoid, serratus anterior, and external intercostals are all muscles that contribute to the elevation of the ribs during breathing. However, the external oblique muscle is primarily responsible for lateral flexion and rotation of the trunk, rather than rib elevation.
13.
Each of the following muscles can function in expiration, except the
Correct Answer
C. Scalenes
Explanation
The scalenes are not involved in expiration. They are a group of muscles located in the neck that primarily function in neck movement and assist in breathing by elevating the upper ribs during inhalation. However, during expiration, the primary muscles involved are the internal intercostals, which help to depress the ribs and decrease the volume of the thoracic cavity. Therefore, the scalenes do not play a significant role in expiration.
14.
Henry's law states that
Correct Answer
C. The volume of gas that will dissolve in a solvent is proportional to the solubility of the gas and the gas pressure
Explanation
Henry's law states that the volume of gas that will dissolve in a solvent is proportional to the solubility of the gas and the gas pressure. This means that as the solubility of the gas increases or the gas pressure increases, more gas molecules will dissolve in the solvent. Conversely, if the solubility or gas pressure decreases, less gas will dissolve. This relationship between gas solubility, gas pressure, and the volume of gas dissolved is described by Henry's law.
15.
Dalton's law states that
Correct Answer
C. In a mixture of gases like air, the total pressure is the sum of the individual partial pressures of the gases in the mixture
Explanation
Dalton's law of partial pressures states that in a mixture of gases, the total pressure exerted is equal to the sum of the partial pressures of each individual gas in the mixture. This means that the pressure exerted by each gas is independent of the presence of other gases in the mixture. Each gas behaves as if it occupies the entire volume and exerts its own pressure, contributing to the total pressure of the mixture. This law is important in understanding the behavior of gases in various applications, such as in the atmosphere or in industrial processes.
16.
The process by which dissolved gases are exchanged between the blood and interstitial fluids is
Correct Answer
A. Internal respiration
Explanation
Internal respiration refers to the exchange of gases (oxygen and carbon dioxide) between the blood and the body's tissues. It occurs in the capillaries, where oxygen from the blood diffuses into the interstitial fluid and then into the cells, while carbon dioxide produced by the cells diffuses into the interstitial fluid and then into the blood. This process is essential for delivering oxygen to the cells and removing carbon dioxide, allowing for cellular respiration to occur. Breathing, external respiration, and pulmonary ventilation are all related to the exchange of gases between the atmosphere and the lungs, while cellular respiration refers to the metabolic process in cells that produces energy.
17.
At a PO2 of 70mm and normal temperature and pH, hemoglobin is ______ saturated with oxygen
Correct Answer
B. Over 90%
Explanation
At a PO2 of 70mm and normal temperature and pH, hemoglobin is over 90% saturated with oxygen. This means that more than 90% of the binding sites on hemoglobin are occupied by oxygen molecules. Hemoglobin's ability to bind oxygen is influenced by the partial pressure of oxygen in the blood (PO2), and at a PO2 of 70mm, hemoglobin has a high affinity for oxygen, resulting in a high level of oxygen saturation.
18.
Most of the oxygen transported by the blood is
Correct Answer
E. Bound to hemoglobin
Explanation
Oxygen is primarily transported in the blood by binding to hemoglobin, a protein found in red blood cells. Hemoglobin has a high affinity for oxygen, allowing it to easily bind to oxygen molecules in the lungs and release them in tissues that need oxygen. This process is crucial for oxygen delivery to all parts of the body.
19.
Most of the carbon dioxide in the blood is transported as
Correct Answer
B. Bicarbonate ions
Explanation
The majority of carbon dioxide in the blood is transported as bicarbonate ions. When carbon dioxide enters the red blood cells, it combines with water to form carbonic acid. Carbonic acid then dissociates into bicarbonate ions and hydrogen ions. The bicarbonate ions are then transported out of the red blood cells and into the plasma, where they are carried to the lungs to be exhaled. This process helps to regulate the pH of the blood and allows for efficient transport of carbon dioxide from the tissues to the lungs.
20.
The most important chemical regulator of respiration is
Correct Answer
C. Carbon dioxide
Explanation
Carbon dioxide is the most important chemical regulator of respiration because it plays a crucial role in controlling the rate and depth of breathing. When carbon dioxide levels in the blood increase, it triggers the respiratory center in the brain to stimulate faster and deeper breathing, allowing the body to eliminate excess carbon dioxide. Conversely, when carbon dioxide levels decrease, the respiratory center reduces the rate and depth of breathing. This regulation helps to maintain the balance of gases in the body and ensure efficient gas exchange in the lungs.
21.
The pneumotaxic center of the pons
Correct Answer
C. Modifies the rate and depth of breathing
Explanation
The pneumotaxic center of the pons is responsible for modifying the rate and depth of breathing. It helps regulate the duration and intensity of each breath, ensuring that the respiratory pattern is appropriate for the body's needs. By adjusting the rate and depth of breathing, the pneumotaxic center helps maintain a balance between oxygen intake and carbon dioxide elimination, ensuring proper gas exchange in the lungs. This control is essential for maintaining homeostasis and meeting the body's metabolic demands.
22.
In quiet breathing
Correct Answer
B. Inspiration involves muscular contractions and expiration is passive
Explanation
In quiet breathing, inspiration involves muscular contractions because the diaphragm and intercostal muscles contract to expand the thoracic cavity and allow air to enter the lungs. On the other hand, expiration is passive because it does not require any muscular effort. The relaxation of the diaphragm and intercostal muscles allows the thoracic cavity to decrease in size, causing air to be pushed out of the lungs.
23.
External respiration involves the
Correct Answer
D. Diffusion of gases between the alveoli and the circulating blood
Explanation
External respiration refers to the process of exchanging gases between the lungs and the bloodstream. In this process, oxygen from the inhaled air diffuses across the walls of the alveoli (tiny air sacs in the lungs) into the surrounding capillaries, where it binds to hemoglobin in red blood cells. At the same time, carbon dioxide, a waste product of cellular respiration, diffuses from the capillaries into the alveoli to be exhaled. Therefore, the correct answer is "diffusion of gases between the alveoli and the circulating blood."
24.
If a student inhales as deeply as possible and then blows the air out until he cannot exhale any more, the amoutn of air that he expelled would be his
Correct Answer
B. Vital capacity
Explanation
When a student inhales as deeply as possible and then exhales until they cannot exhale any more, the amount of air expelled is known as their vital capacity. Vital capacity is the maximum amount of air a person can exhale after taking the deepest breath possible. It is the sum of the inspiratory reserve volume (the amount of air that can be inhaled after a normal inhalation), tidal volume (the amount of air inhaled and exhaled during normal breathing), and expiratory reserve volume (the amount of air that can be exhaled after a normal exhalation). Therefore, the correct answer is vital capacity.
25.
The respiratory rate times the tidal volume corrected for dead air is the
Correct Answer
E. Alveolar ventilation rate
Explanation
The alveolar ventilation rate is the correct answer because it represents the volume of fresh air that reaches the alveoli per minute. It is calculated by multiplying the respiratory rate (number of breaths per minute) by the tidal volume (volume of air inhaled or exhaled per breath) corrected for dead air (air that remains in the conducting airways and does not reach the alveoli). This measurement is important in assessing the efficiency of gas exchange in the lungs.
26.
Which of the following factors would increase the amount of oxygen discharged by hemoglobin to peripheral tissues?
Correct Answer
C. Decreased pH
Explanation
A decrease in pH would increase the amount of oxygen discharged by hemoglobin to peripheral tissues. This is because a decrease in pH indicates a higher concentration of hydrogen ions, which causes hemoglobin to have a lower affinity for oxygen. As a result, hemoglobin releases more oxygen to the peripheral tissues.
27.
During swallowing, the
Correct Answer
E. Both B and C
Explanation
During swallowing, the intrinsic laryngeal muscles relax to allow the passage of food or liquid, while the extrinsic laryngeal muscles contract to elevate and stabilize the larynx. This combination of actions results in the closure of the glottis, preventing food or liquid from entering the airway, and the depression of the epiglottis, which helps direct the swallowed material into the esophagus. Therefore, both options B and C are correct as they describe the actions of the intrinsic and extrinsic laryngeal muscles during swallowing.
28.
Damage to the septal cells of the lungs would result in
Correct Answer
C. Alveolar collapse
Explanation
Damage to the septal cells of the lungs can lead to a loss of structural support in the alveoli. This loss of support can cause the alveoli to collapse, resulting in decreased gas exchange. When the alveoli collapse, the surface area available for gas exchange decreases, making it harder for oxygen to enter the bloodstream and for carbon dioxide to be removed. This can lead to respiratory difficulties and a decrease in overall lung function.
29.
Which of the following would be greater?
Correct Answer
B. The percent of oxygen saturation of hemoglobin when the pH is 7.6
Explanation
The percent of oxygen saturation of hemoglobin is typically higher at a higher pH level. This is because a higher pH level indicates a more basic environment, which favors the binding of oxygen to hemoglobin. Therefore, the percent of oxygen saturation of hemoglobin is likely to be greater when the pH is 7.6 compared to when the pH is 7.2.
30.
Which of hte following would be greater?
Correct Answer
B. The percent of oxygen saturation of hemoglobin when the temperature is 40 degrees centigrade
Explanation
The percent of oxygen saturation of hemoglobin decreases as the temperature increases. Therefore, the percent of oxygen saturation of hemoglobin when the temperature is 37 degrees centigrade would be greater than when the temperature is 40 degrees centigrade.
31.
Which of the following would be greater?
Correct Answer
A. The percent of oxygen saturation of hemoglobin when the DPG level is low
Explanation
When the DPG (diphosphoglycerate) level is low, it means that there is less DPG present in the blood. DPG helps in the release of oxygen from hemoglobin, so when the DPG level is low, less oxygen is released and thus the percent of oxygen saturation of hemoglobin is greater. Therefore, the percent of oxygen saturation of hemoglobin is greater when the DPG level is low.
32.
All of the following are present prior to birth, except the:
Correct Answer
E. Alveoli are expanded
Explanation
Prior to birth, the alveoli in the lungs are not expanded. This is because the alveoli, which are tiny air sacs in the lungs responsible for gas exchange, do not fully develop and expand until after birth. At birth, the first breaths taken by the newborn help to inflate and expand the alveoli, allowing for proper oxygenation of the blood. Therefore, the statement that alveoli are expanded is incorrect.
33.
With aging
Correct Answer
E. Pulmonary ventilation decreases
Explanation
As a person ages, their pulmonary ventilation, or the amount of air they can breathe in and out in one minute, decreases. This is because the lungs lose some of their elasticity and the respiratory muscles may become weaker. This decrease in pulmonary ventilation can lead to reduced oxygen intake and potentially impact overall respiratory function.