Respiratory System Quiz AP bio
Which of the following structures is found within the lungs and helps facilitate gas exchange? Possible Answers: Microvilli Alveoli Trachea Secretory vesicles Bronchi
Correct answer: Alveoli Explanation: Alveoli are at the end of the respiratory pathway in humans, and act as a site of gas exchange (carbon dioxide and oxygen). The path of air through the respiratory tract is: trachea, bronchi, bronchioles, alveoli. It is important to note that no gas exchange takes place in the bronchi, but does in the bronchioles, which are passageways that branch off from the main bronchi and eventually lead to alveolar ducts. Micorvilli are found int he small intestine and act to increase the surface area in order to increase nutrient absorption. Secretory vesicles are used to transport proteins, hormones, and other molecules from a cell into the extracellular space.
Which of these describes the gas exchange that occurs in the alveoli? Possible Answers: Exchange of carbon dioxide and oxygen between the blood vessels and the alveoli Exchange of oxygen and hydrogen between the blood vessels and the alveoli The process of bringing air into the lungs The process of cleansing the air inhaled through the bronchi Exchange of molecules across the pulmonary cell surfaces
Correct answer: Exchange of carbon dioxide and oxygen between the blood vessels and the alveoli Explanation: Diffusion is the spontaneous process by which substances move from areas of high to low concentration. During diffusion in alveoli, the high levels of CO2 that are in the blood vessels surrounding the alveoli causes it to diffuse out of the blood vessels and into the alveoli where there are low levels of CO2 (atmospheric air is about 0.04%CO2 ). In the same way, high levels of oxygen in the alveoli diffuses into the area of low oxygen concentration within the blood vessels.
What phenomenon occurs in the blood when an individual holds their breath for an extended period? Possible Answers: Alkalosis Decreased heart rate Acidosis Auto-immune disease Combustion
Correct answer: Acidosis Explanation: When you are not breathing, your respiratory system cannot perform its function. Unwanted gases, such as carbon dioxide, cannot be removed from the system and necessary gases, such as oxygen, cannot enter the system. This causes a buildup of carbon dioxide in the body, which leads to acidosis. Carbon dioxide is converted to carbonic acid via carbonic anhydrase. This carbonic acid builds in the blood, lowering its pH.
Which best describes the structure of the alveoli? Possible Answers: A thin layer of epithelial cells directly connected to endothelial cells in capillaries A thick layer of epithelial cells separated from endothelial cells in capillaries by interstitial fluid Tiny sacks that fill up with blood to facilitate the exchange of oxygen and nutrients A thin layer of epithelial cells separated from endothelial cells in capillaries by interstitial fluid A thick layer of epithelial cells directly connected to endothelial cells in capillaries
correct answer: A thin layer of epithelial cells directly connected to endothelial cells in capillaries Explanation: The alveoli's structure maximizes the efficient transfer of gas from air to the capillaries and vice versa. Therefore the contact point between air and the capillaries needs to be as thin as possible so gas has only a short distance to diffuse. Alveoli are therefore made up of a thin layer of epithelial cells that are in direct contact with endothelial cells in the capillaries.
Which of the following anatomical structures is found within the respiratory system? Possible Answers: Alveoli Pharynx Trachea All of these structures are found within the respiratory system Bronchiole
correct answer: All of these structures are found within the respiratory system Explanation: The respiratory system allows air to enter the lungs from the outside environment and facilitates gas exchange with the blood. Air initially enters through the mouth or nose, passes through the pharynx and larynx, and enters the trachea. From the trachea, air travels through branching structures from bronchi, to bronchiole, to alveoli. Gas exchange occurs between the air in the alveoli and the capillaries surrounding the alveoli.
What is cell type forms the lining of the alveoli? Possible Answers: Endothelial Apical Basal Epithelial Respiratory
hat is cell type forms the lining of the alveoli? Possible Answers: Endothelial Apical Basal Epithelial Respiratory
he alveoli of the human lungs cluster together in alveolar sacs. These clusters are commonly said to resemble clusters of grapes, as the nearly spherical alveoli appear to bud away from "stems" (alveolar ducts). Which response best explains the alveoli's spherical shape? Possible Answers: Some extracellular matrix (ECM) material helps connect the alveoli to the capillaries; the presence of this material causes the alveoli to "pucker" into approximately spherical shapes Alveoli's spherical shape gives them the maximal amount of surface area possible for their volume; this large surface area allows for highly efficient gas exchange between the blood and the air in the lungs The alveoli lie immediately adjacent to the capillaries around the lungs; the alveoli's spherical shape is nothing more than the result of the capillaries' generally round shape The epithelial cells of the alveoli have a natural tendency to form spherical shapes; the alveoli's shape is a result of this tendency and is somewhat of a biological accident
Correct answer: Alveoli's spherical shape gives them the maximal amount of surface area possible for their volume; this large surface area allows for highly efficient gas exchange between the blood and the air in the lungs Explanation: The spherical or grape-like shape of the alveoli allows for maximum contact between the alveoli and the capillaries that surround them. The alveoli are filled with air that has been taken into the lungs from the environment, so a high surface area allows for maximum contact between air from the environment and capillaries. Oxygen rapidly diffuses through the exceptionally thin alveolar walls to the capillaries, which carry hemoglobin-containing blood cells that bind to the oxygen and shuttle it around the body. Blood cells also release carbon dioxide into the alveoli and lungs, which is why this process is called gas exchange. Capillaries are considerably smaller than alveoli; they surround the alveoli like a mesh, and are certainly not the cause of the alveoli's shape. Furthermore, though the cells of the alveoli do secrete extracellular matrix material, the cells affect the structure of the extracellular matrix, rather than the other way around. The shape of the alveoli is crucial to their function in gas exchange and cannot be considered an "accident," or the unexpected result of the shapes of other biological structures.
Which of the given circulatory system elements has the highest partial pressure of oxygen? Possible Answers: Left atrium Superior vena cava Pulmonary arteries Right atrium Inferior vena cava
Correct answer: Left atrium Explanation: The left atrium receives blood from the pulmonary veins, which carry blood that was freshly oxygenated from the lungs to the heart. The partial pressure of oxygen is always highest soon after oxygenation, thus blood returning from the lungs would have a high partial pressure. The superior and inferior vena cavae return deoxygenated blood from the body to the heart, and would have very low oxygen partial pressures. The right atrium receives this deoxygenated blood from the vena cavae and transfers it to the right ventricle. From the ventricle, the deoxygenated blood is transported to the lungs via the pulmonary arteries. It only becomes oxygenated again after reaching the lungs, and then returns to the heart through the pulmonary veins.
What respiratory structure connects the nasal passages and the mouth? Possible Answers: Pharynx Bronchioles Trachea Larynx Lungs
Correct answer: Pharynx Explanation: The pharynx, located posteriorly (behind) the nasal passages and the mouth, is responsible for collecting the air that is taken in via the nose and mouth. The pharynx then passes the air to the larynx before it flows into the trachea. The trachea carries the air to the bronchioles, which end in terminal alveoli in the lungs.
What happens to the pressure of the lungs to initiate inspiration? Possible Answers: Pressure decreases, then increases Pressure remains constant Pressure increases Pressure increases, then decreases Pressure decreases
Correct answer: Pressure decreases Explanation: During inspiration, the lungs expand as the diaphragm contracts and internal intercostal muscles relax. As the volume of the thoracic cavity increases, its pressure decreases. This creates a pressure gradient, driving air from an area of high pressure (the environment) into the area of low pressure (the lungs).
What causes air to enter human lungs? Possible Answers: Cillia in the trachea guide the flow of air into the lungs. The decreased concentration of O2 in the lungs decreases the density of that air, and denser air outside the body "sinks" into the lungs. Smooth muscle in the trachea guides the flow of air into the lungs. The contraction of the diaphragm increases the volume of the lungs, decreasing the pressure relative to the air outside the body. Air diffuses into the lungs due to the decreased O2 content relative to the air outside our body.
Correct answer: The contraction of the diaphragm increases the volume of the lungs, decreasing the pressure relative to the air outside the body. Explanation: Increasing the volume of a container (in this case, the lungs) while keeping the contents (air molecules) the same will decrease the pressure. If no barrier is present (as when holding your breath), pressure will tend to equalize between areas of differing pressure. In order to equalize the pressure, air molecules from outside the body rush into the expanded lungs. The concentration of oxygen does not impact inhalation, and cilia are not used to inhale.
The function of an alveolus is most evident in the basic anatomy of which type of alveolar cell? Possible Answers: The phagocytic alveolar macrophages Clara cells The very thin type 1 alveolar cells The cuboidal or round type 2 alveolar cells
Correct answer: The very thin type 1 alveolar cells Explanation: The vast majority of the surface area of an alveolus is made up of type 1 alveolar cells, which are squamous (flat), thin epithelial cells that allow rapid gas exchange between the air inside the alveoli and blood in the surrounding capillaries. The healthy adult human has millions of alveoli in his/her lungs, providing a huge total surface area across which gas can diffuse, letting oxygen into the bloodstream and carbon dioxide out.
How many lobes does the right lung have? Possible Answers: Four Five Three One Two
Correct answer: Three Explanation: The right lung contains three lobes: upper, middle, and lower. The left lungs contains two lobes: upper and lower. The left lung is designed to be smaller than the right in order to accommodate the heart, which is situated slightly to the left.
Which portion of the respiratory system extends from the larynx to the bronchi? Possible Answers: Bronchioles Trachea Pharynx Alveoli Esophagus
Correct answer: Trachea Explanation: Anterior to the esophagus, the trachea begins at the larynx (voice box) and extends down towards the lungs where it splits into the bronchi. The trachea is a conducting structure, meaning no gas exchange occurs in the trachea. Instead, it is held open by "C" shaped rings of cartilage to allow maximum airflow between the lungs and the air in the environment.
Which of the following structures is not found within the lungs? Possible Answers: Trachea Alveoli Bronchioles Bronchi
Correct answer: Trachea Explanation: The lungs contain the bronchioles, the alveoli, and part of the bronchi. The trachea carries inhaled air into the bronchi, but it is not actually enclosed by the bronchi— the lungs only enclose structures that arise after the bronchi branch away from the trachea.
Which of the following answers lists the correct order of respiratory structures that air moves through as it is drawn into the lungs? Possible Answers: Bronchi, bronchioles, alveoli, trachea Trachea, bronchioles, bronchi, alveoli Trachea, bronchi, bronchioles, alveoli Alveoli, trachea, bronchi, bronchioles
Correct answer: Trachea, bronchi, bronchioles, alveoli Explanation: Air enters the body of most terrestrial vertebrates through the nose or the mouth; the air then passes through the trachea to narrower tubes called the bronchi, to still narrower tubes called the bronchioles. The bronchioles "dead end" into structures called alveoli, which is where gas exchange of oxygen and carbon dioxide takes place with the blood in adjacent capillaries.
The right lung has __________ lobes, and the left lung has __________ lobes. Possible Answers: two . . . two three . . . three three . . . three four . . . two two . . . three
Correct answer: three . . . three Explanation: The right lung has 3 lobes and left lung has only 2 lobes to allow room for the heart. The majority of the heart is on the left side of the body since the left ventricle is the largest and thickest-walled chamber of the heart.
Terrestrial animals must combat the drying out of respiratory surfaces due to evaporation. What is one strategy they use? Possible Answers: Excretion of fluids from walls of lungs Folding the respiratory surface into the body Increased perspiration of cells on respiratory surface Having very low respiratory rates Increased metabolism
correct answer: Folding the respiratory surface into the body Explanation: By folding the respiratory surface into the body, terrestrial animals increase the humidity of the environment of the respiratory surface, which will minimize evaporation and maintain moisture. Note that water loss via evaporation and perspiration accounts for the majority of water loss in terrestrial mammals.
How does hyperventilating change the blood chemistry in the human body? Possible Answers: Hyperventilating will not affect the blood's pH. Hyperventilating will release more CO2 and result in an increase in the blood's pH Hyperventilating will retain more CO2 and result in an increase in the blood's pH Hyperventilating will release more CO2 and result in a drop in the blood's pH Hyperventilating will retain more CO2 and result in a decrease in the blood's pH
correct answer: Hyperventilating will release more CO2 and result in an increase in the blood's pH Explanation: CO2+H20↔HCO−3+H+ Hyperventilation will result in the expiration of more CO2. It can be deduced that a greater amount of expired CO2 will cause the above equation to shift to the left. The shifting of the equation to the left will further promote the conversion of H+ and HCO−3 to CO2 and H20. Since the body uses HCO−3 as a buffer, there will be a greater quantity of the bicarbonate in the body than H+. When the equation shifts to the left, the H+ will deplete at a faster rate and result in a higher HCO−3 to H+ ratio. A higher HCO−3 to H+ ratio will cause the body's blood to become more basic (increase in pH); therefore, hyperventilation increases blood bascicity.
Which statement describes the pressure in the lungs during exhalation? Possible Answers: Lung pressure must be lower than atmospheric pressure Lung pressure must be equal to atmospheric pressure Lung pressure must be higher than atmospheric pressure Lung pressure should not change during the process
correct answer: Lung pressure must be higher than atmospheric pressure Explanation: This question requires a basic understanding of general chemistry and/or general physics. Remember that gas will only move from an area of high pressure to low pressure; thus, if air is moving out of the lungs, the pressure inside of the lungs must be greater than the pressure outside of the lungs. The point at which air does not move in or out of the lungs is a signal that the pressure of the gas inside of the lungs is equal to that of atmospheric pressure. In a biological sense, remember that the diaphragm contracts to cause inhalation, which results from negative or decreased pressure in the lungs. When the diaphragm relaxes, the pressure in the lungs must increase again. The increase in pressure forces the air out of the lungs and back into the atmospheric environment.
How is oxygen carried after entering the blood of the pulmonary capillaries? Possible Answers: Oxygen is free floating in the plasma of the blood Oxygen is carried by hemoglobin Oxygen diffuses into the cell membranes of red blood cells Oxygen diffuses through all the cells in the body Oxygen is carried by white blood cells
correct answer: Oxygen is carried by hemoglobin Explanation: Hemoglobin is the main oxygen carrier in the human body. Each hemoglobin protein is able to carry four oxygen molecules. As the hemoglobin travels through the blood vessels of the body, the oxygen is released to tissues and used in the electron transport chain. If oxygen is unable to bind to hemoglobin, our bodies cannot carry the needed oxygen to the tissues of the body. This can occur when carbon monoxide displaces oxygen from hemoglobin.
Which of the following is the correct path of air through the respiratory system? Possible Answers: Larynx, pharynx, bronchi, trachea, lungs Larynx, trachea, bronchi, pharynx, lungs Bronchi, pharynx, larynx, trachea, lungs Pharynx, larynx, trachea, bronchi, lungs Trachea, bronchi, larynx, pharynx, lungs
correct answer: Pharynx, larynx, trachea, bronchi, lungs Explanation: Air enters the body through the nose or mouth, and is transferred to the pharynx (the upper portion of the throat located at the back of the mouth). The larynx is commonly called the "voice box," and is the lower portion of the throat connected to the pharynx. From there, air enters the trachea and flows into the chest. The trachea branches into two bronchi, which continue to branch and divide as the air is carried into the lungs.
What type of epithelial tissue surrounds the alveoli? Possible Answers: Simple columnar epithelium Simple cuboidal epithelium Stratified squamous epithelium Simple squamous epithelium
correct answer: Simple squamous epithelium Explanation: Alveoli are the site of gas exchange in the lungs. Because rapid diffusion of gases is necessary between the capillaries and the alveoli, a very thin epithelial layer is needed. As a result, alveoli use simple squamous epithelium so that gases can easily diffuses to and from the bloodstream.
What is the purpose of the nasal passage? Possible Answers: The nasal passage filters air The nasal passage is largely vestigial in humans The nasal passage allows transfer of oxygen to the nose and face The nasal passage warms or cools air to body temperature and filters air
correct answer: The nasal passage warms or cools air to body temperature and filters air Explanation: The nasal passage's main function is to heat or cool air before it enters the lungs. The cilia, mucous and hair also help filter air since the respiratory system is very sensitive to allergens and infection. Also, the lungs need to be kept moist and lubricated, so dry air is damaging. No gas exchange occurs in the nasal passage, it is merely a conduction zone through which air must travel before it gets to the alveoli where gas exchange occurs with the pulmonary capillaries.
Choose the incorrect statement regarding gas exchange in the alveoli of the lungs. Possible Answers: Gases move between alveoli and blood vessels via passive diffusion The partial pressure of carbon dioxide is lower in the systemic arteries than it is in the body tissues In the lungs, oxygen diffuses from the alveoli into the blood vessels The partial pressure of oxygen is lower in systemic arteries than in systemic veins Carbon dioxide diffuses from the blood vessels into the alveoli for expiration
correct answer: The partial pressure of oxygen is lower in systemic arteries than in systemic veins Explanation: We know that systemic arteries carry oxygenated blood away from the heart and that these vessels pass through tissues, allowing oxygen to diffuse into the tissues and carbon dioxide to diffuse out into the bloodstream. We also know that veins carry blood back to the heart, which by this time is oxygen-poor due to its gas exchange with the tissues of the body. The partial pressure of oxygen in veins must be lower than it is in arteries, since the veins carry deoxygenated blood. The remaining statements regarding gas exchange are true.
Before it enters the lungs, air must pass through which of the following structures? Possible Answers: Nephrons Alveoli The pharynx The esophagus
correct answer: The pharynx Explanation: After entering the nose and mouth, air is passed into the pharynx. It then travels to the larynx, which houses the vocal cords, before entering the trachea. The trachea transports the air into the thoracic cavity before branching into the primary bronchi. The right bronchus carries air to the right lung; the left bronchus carries air to the left lung. Of the given answer options, air only passes through the pharynx before entering the lungs. Alveoli are found in the lungs and the primary site of gas exchange; however, the question specifies a structure before the air enters the lungs. The esophagus transports food, and is not involved in respiration. Nephrons are the function units of the excretory system, and are located in the kidneys.
What is the function of nasal cilia? Possible Answers: To support nasal cartilage To create mucus Allow for the insertion of a nasal cannula To warm, moisturize, and filter inhaled air Olfaction
correct answer: To warm, moisturize, and filter inhaled air Explanation: The nose is the primary passageway of air into the lungs. Before air can safely enter the body, it must be brought to body temperature, moisturized and cleansed of any particles that could damage the respiratory system or cause infection. Mucous is produced by goblet cells. Olfaction is carried out by specialized neurons in the nose that bind to certain molecules and send information to the brain.
Example Question #81 : Systems Physiology Gases diffuse down their concentration gradients, so in order for the body to exchange respiratory gases with the air as needed, air breathed into the lungs must have a __________ concentration of oxygen and a(n) __________ concentration of carbon dioxide compared to the blood in the lungs. Possible Answers: lower . . . higher higher . . . lower lower . . . equal higher . . . equal
correct answer: higher . . . lower Explanation: Oxygen is taken up from the blood by all cells to be used in ATP production. The process of cellular respiration (energy production) creates carbon dioxide as a waste product, which, if accumulated, can cause the blood to become dangerously acidic. Gases in the lungs diffuse passively into or out of the air entirely based on where the concentration is lowest. Thus, oxygen levels in the blood must be lower in concentration than those in the lungs in order for oxygen to enter the blood, and carbon dioxide levels in the blood must be higher than those in the lungs order for carbon dioxide to exit.
To initiate inhalation, the diaphragm contracts, making the pressure inside the lungs __________. Possible Answers: zero the same as the pressure outside the body lower than the pressure outside the body None of these higher than the pressure outside the body
correct answer: lower than the pressure outside the body Explanation: Inhalation happens by making the pressure in the lungs lower relative to the pressure outside the body. When the diaphragm contracts, it increases the volume of the thoracic cavity. By Boyle's law, there is an inverse relationship between pressure and volume of a gas. Thus the pressure of the thoracic cavity decreases and since air will flow from high to low pressure, this pulls air into the lungs during inhalation.
