what happens to the air pressure in the lungs for exhalation to occur? course hero

by Leatha Jacobs 10 min read

What happens to the air in the lungs during inhalation?

Answers: Selected Answer: True True Fals e. Question 12 1 out of 1 points Disease caused by a virus that has been almost completely wiped out in the U.S. causing authorities to debate whether the need for the vaccine still exists. Selected Answer: b. Polio.

How does air enter and exit the lungs during inspiration and expiration?

May 08, 2021 · If the pressure is greater in the lungs than outside the lungs, then air comes out. If the pressure in the lungs is less than outside of lungs, then air is breathed in. 2.At altitude, the reduced oxygen content of the blood induces breathing instability, with periods of deep and rapid breathing alternating with central apnea. This breathing pattern is called high-altitude periodic …

What happens to the pressure in the lungs during expiration?

Air flows because of pressure differences between the atmosphere and the gases inside the lungs. Air, like other gases, flows from a region with higher pressure to a region with lower pressure. Muscular breathing movements and recoil of elastic tissues create the changes in pressure that result in ventilation.

What happens to the air pressure inside the lungs when volume increases?

Mar 05, 2017 · Question 17 1 out of 1 points What happens to the air pressure in the lungs for from BIOL 1409 at Dallas County Community College. Study Resources. ... Question 17 1 out of 1 points What happens to the air pressure in the lungs for inhalation to occur? Selected Answer: b. ... Course Hero is not sponsored or endorsed by any college or university

What causes the lungs to be pulled outward during inspiration?

This is because of the adhesive nature of the pleural fluid, which allows the lungs to be pulled outward when the thoracic wall moves during inspiration. The recoil of the thoracic wall during expiration causes compression of the lungs. Contraction and relaxation of the diaphragm and intercostals muscles (found between the ribs) cause most of the pressure changes that result in inspiration and expiration. These muscle movements and subsequent pressure changes cause air to either rush in or be forced out of the lungs.

How to describe pulmonary ventilation?

By the end of this section, you will be able to: 1 Describe the mechanisms that drive breathing 2 Discuss how pressure, volume, and resistance are related 3 List the steps involved in pulmonary ventilation 4 Discuss the physical factors related to breathing 5 Discuss the meaning of respiratory volume and capacities 6 Define respiratory rate 7 Outline the mechanisms behind the control of breathing 8 Describe the respiratory centers of the medulla oblongata 9 Describe the respiratory centers of the pons 10 Discuss factors that can influence the respiratory rate

What is intrapleural pressure?

Intrapleural pressure is the pressure of the air within the pleural cavity, between the visceral and parietal pleurae. Similar to intra-alveolar pressure, intrapleural pressure also changes during the different phases of breathing.

What is the respiratory system disorder?

Disorders of the Respiratory System: Sleep Apnea. Sleep apnea is a chronic disorder that can occur in children or adults, and is characterized by the cessation of breathing during sleep. These episodes may last for several seconds or several minutes, and may differ in the frequency with which they are experienced.

What is the process of breathing?

Pulmonary ventilation is the process of breathing, which is driven by pressure differences between the lungs and the atmosphere. Atmospheric pressure is the force exerted by gases present in the atmosphere. The force exerted by gases within the alveoli is called intra-alveolar (intrapulmonary) pressure, whereas the force exerted by gases in the pleural cavity is called intrapleural pressure. Typically, intrapleural pressure is lower, or negative to, intra-alveolar pressure. The difference in pressure between intrapleural and intra-alveolar pressures is called transpulmonary pressure. In addition, intra-alveolar pressure will equalize with the atmospheric pressure. Pressure is determined by the volume of the space occupied by a gas and is influenced by resistance. Air flows when a pressure gradient is created, from a space of higher pressure to a space of lower pressure. Boyle’s law describes the relationship between volume and pressure. A gas is at lower pressure in a larger volume because the gas molecules have more space to in which to move. The same quantity of gas in a smaller volume results in gas molecules crowding together, producing increased pressure.

What is the ability to breathe?

However, the ability to breathe—to have air enter the lungs during inspiration and air leave the lungs during expiration —is dependent on the air pressure of the atmosphere and the air pressure within the lungs.

How much is atmospheric pressure?

Atmospheric pressure can be expressed in terms of the unit atmosphere, abbreviated atm, or in millimeters of mercury (mm Hg). One atm is equal to 760 mm Hg, which is the atmospheric pressure at sea level. Typically, for respiration, other pressure values are discussed in relation to atmospheric pressure.

Mechanisms of Breathing

  • The alveolar and intrapleural pressures are dependent on certain physical features of the lung. However, the ability to breathe—to have air enter the lungs during inspiration and air leave the lungs during expiration—is dependent on the air pressure of the atmosphere and the air pressure within the lungs.
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Pulmonary Ventilation

  • The difference in pressures drives pulmonary ventilation because air flows down a pressure gradient, that is, air flows from an area of higher pressure to an area of lower pressure. Air flows into the lungs largely due to a difference in pressure; atmospheric pressure is greater than intra-alveolar pressure, and intra-alveolar pressure is greater than intrapleural pressure. Air flows out …
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Respiratory Volumes and Capacities

  • Respiratory volumeis the term used for various volumes of air moved by or associated with the lungs at a given point in the respiratory cycle. There are four major types of respiratory volumes: tidal, residual, inspiratory reserve, and expiratory reserve (Figure 4). Tidal volume (TV) is the amount of air that normally enters the lungs during quiet breathing, which is about 500 milliliters…
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Respiratory Rate and Control of Ventilation

  • Breathing usually occurs without thought, although at times you can consciously control it, such as when you swim under water, sing a song, or blow bubbles. The respiratory rate is the total number of breaths, or respiratory cycles, that occur each minute. Respiratory rate can be an important indicator of disease, as the rate may increase or decrease during an illness or in a dis…
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Chapter Review

  • Pulmonary ventilation is the process of breathing, which is driven by pressure differences between the lungs and the atmosphere. Atmospheric pressure is the force exerted by gases present in the atmosphere. The force exerted by gases within the alveoli is called intra-alveolar (intrapulmonary) pressure, whereas the force exerted by gases in the pleural cavity is called intr…
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Self Check

  • Answer the question(s) below to see how well you understand the topics covered in the previous section.
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Glossary

  • alveolar dead space:air space within alveoli that are unable to participate in gas exchange anatomical dead space:air space present in the airway that never reaches the alveoli and therefore never participates in gas exchange apneustic center:network of neurons within the pons that stimulate the neurons in the dorsal respiratory group; controls the depth of inspiration atmo…
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