What causes air to enter human lungs? The contraction of the diaphragm increases the volume of the lungs, decreasing the pressure relative to the air outside the body. Smooth muscle in the trachea guides the flow of air into the lungs. Air diffuses into the lungs due to the decreased O2 content relative to the air outside our body. The cilia 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.

What causes air to enter human lungs? The contraction of the diaphragm increases the volume of the lungs, decreasing the pressure relative to the air outside the body. Smooth muscle in the trachea guides the flow of air into the lungs. Air diffuses into the lungs due to the decreased O2 content relative to the air outside our body. The cilia 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.

Biology 2e

2nd Edition

ISBN:9781947172517

Author:Matthew Douglas, Jung Choi, Mary Ann Clark

Publisher:Matthew Douglas, Jung Choi, Mary Ann Clark

Chapter39: The Respiratory System

Section: Chapter Questions

Problem 8RQ: Of the following, which does not explain why the partial pressure of oxygen is lower in the lung...

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A partial pressure gradient of oxygen exists between ________. a. air and lungs b. lungs and metabolically active tissues c. air at sea level and air at high altitudes d. all of the above
Figure 39.7 Which of the following statements about the mammalian respiratory system is false? When we breathe in, air travels from the pharynx to the trachea. The bronchioles branch into bronchi. Alveolar ducts connect to alveolar sacs. Gas exchange between the lung and blood takes place in the alveolus.
Of the following, which does not explain why the partial pressure of oxygen is lower in the lung than in the external air? Air in the lung is humidified; therefore, water vapor pressure alters the pressure Carbon dioxide mixes with oxygen Oxygen is moved into the blood and is headed to the tissues Lungs exert a pressure on the air to reduce the oxygen pressure.
The respiratory system_______. a. provides body tissues with oxygen b. provides body tissues with oxygen and carbon dioxide c. establishes how many breaths are taken per minute d. provides the body with carbon dioxide
What controls the movement of the lungs? Describe the flow of air into the lungs. Use the following terms: oral cavity/nasal cavity, trachea, bronchi, bronchioles, alveoli What gases are being exchanged as we inhale? How do the lungs get rid of all the CO2 they've picked up from the blood? Why do the cells in our body need oxygen? Be specific. How do you think your breathing and lungs adapt when you're exercising?
Which of the following is true of the regulation of breathing in humans? Select all that apply. Check All That Apply The concentration of oxygen in the blood is the primary regulator of breathing rate. Breathing can be controlled consciously but is usually subconsciously controlled by the brain. A compound that lowers blood pH would increase respiration rate. Increased levels of blood carbon dioxide lead to an increase in bicarbonate production, which buffers the blood, making it harde oxygen to enter tissues. Respiration increases with the increased production of carbon dioxide during exercise.
Which of the following statements about oxygen transport is TRUE. Increases in temperature and decreases in pH cause myoglobin to release oxygen to improve delivery to the hemoglobin in muscles. A molecule of myoglobin has higher oxygen binding capacity than a molecule of hemoglobin. Myoglobin has a higher oxygen affinity than does hemoglobin. Fetal hemoglobin has a lower affinity for oxygen than maternal hemoglobin, which makes it better suited to extract oxygen from the maternal circulation.
The movement of air out of the lungs during normal expiration is a result of? Air moves out of the lungs due to the relaxation of the diaphragm and intercostal muscles. Air moves out of the lungs due to the passive elastic recoil of the chest wall and lungs. Air is forced out of the lungs due to the active contraction of the abdominal and external intercostal muscles. Air is forced out of the lungs due to the active contraction of the abdominal and internal intercostal muscles.
If water passed over the gills of fish in the same direction as blood flow through the capillaries, how would gas exchange be affected? Select all correct choices. More oxygen would diffuse from the water into the fish's bloodstream. Less oxygen would diffuse from the water into the fish's bloodstream. More carbon dioxide would diffuse out of the fish's bloodstream into the water. Less carbon dioxide would diffuse out of the fish's bloodstream into the water. Gas exchange would remain the same, regardless of the direction of water flow.
Which statement about the regulation of respiration is FALSE? Group of answer choices Respiratory centers in the medulla control the transition from inspiration to expiration. Carbon dioxide concentration is the most important chemical stimulus for regulating respiratory rate. Chemoreceptors in the walls of various arteries are sensitive to carbon dioxide levels in the blood. A group of neurons in the ventral medulla only become active when we need to breathe forcefully. Chemoreceptors may be sensitive to oxygen, carbon dioxide, and/or hydrogen ion concentration.
When holding your breath, you must eventually exhale because: High levels of carbon dioxide are making your blood acidic You need more oxygen to drive cellular respiration You need oxygen to drive glycolysis Increased levels of carbon dioxide are making your blood basic None of the above
In a negative feedback control of respiration, a high level of carbon dioxide in the blood stimulates chemoreceptors. The chemoreceptors then send information to the medulla in the brainstem. The medulla than stimulates an increase in respiratory rate. The integrator in this system is the: Chemoreceptor Carbon dioxide O Lungs Respiratory muscles None of the above