[#6] MECÂNICA RESPIRATÓRIA: COMPLACÊNCIA DA PAREDE TORÁCICA | MK Fisiologia

Summary

In this video, the concept of thoracic wall compliance is explored alongside pulmonary compliance. The presenter explains how the lungs and thoracic wall work together, with the lungs tending to recoil and the thoracic wall expanding or contracting based on volume. The pressure-volume curves are used to illustrate these relationships, highlighting the importance of system compliance in overall respiratory function. Conditions like pneumothorax and obesity are discussed to show how changes in lung or thoracic wall compliance can impact ventilation. The video emphasizes the need to understand these mechanics to fully grasp human respiration.

Takeaways

• 😀 The video discusses the concept of thoracic wall compliance, an important aspect of respiratory mechanics.
• 😀 The host, Miriamutic, emphasizes simplifying human physiology through the MK Fisiologia channel.
• 😀 The video clarifies that while lung compliance is influenced by elastic recoil, the thoracic wall also exhibits elasticity.
• 😀 In pneumothorax, while the lung collapses due to elastic recoil, the thoracic wall expands, showing their opposite mechanical behavior.
• 😀 At rest (end of exhalation), the lung and thoracic wall forces balance out, leading to no net expansion or contraction.
• 😀 Just like lung pressure-volume curves, it's also possible to graph the pressure-volume curve of the thoracic wall.
• 😀 The total system pressure-volume curve is the sum of the lung and thoracic wall pressure-volume curves.
• 😀 Between 0% and 100% of vital capacity, the lung's transmural pressure is positive, meaning it tends to contract.
• 😀 The thoracic wall’s transmural pressure is negative between 0% and 50% of vital capacity, indicating it tends to expand.
• 😀 Above 50% of vital capacity, the thoracic wall’s transmural pressure becomes positive, causing it to contract like the lungs.
• 😀 The system is at rest when the transmural pressures of the lungs and thoracic wall balance out at around 30-40% of vital capacity.
• 😀 Respiratory muscles need to contract to either expand or compress the system beyond the resting state.
• 😀 While analyzing pulmonary compliance and thoracic wall compliance individually is useful, it's crucial to understand how they function together as a system.
• 😀 Conditions like pneumothorax or obesity can affect lung and thoracic wall compliance, leading to altered ventilation.
• 😀 The video encourages viewers to comment, share, and support the channel to help produce more educational content.

Q & A

What is the focus of this video?

The video focuses on explaining the compliance of the thoracic wall, a key concept in respiratory mechanics, and how it interacts with lung compliance.

Who is the presenter in the video?

The presenter is Miriamutic, the creator of the MK Fisiologia channel, which aims to simplify the understanding of human physiology.

What is lung compliance, and how does it relate to elastance?

Lung compliance refers to the ability of the lungs to expand and contract. It is inversely related to elastance, which is the lung's tendency to recoil or shrink.

What happens during a pneumothorax?

In a pneumothorax, the lung collapses due to the recoil of the lung tissue, while the thoracic wall expands. This results in a separation between the lung and the thoracic wall.

What is the pressure-volume curve of the thoracic wall?

The pressure-volume curve of the thoracic wall shows how its transmural pressure changes with lung volume. It indicates that at lower lung volumes, the thoracic wall tends to expand, and at higher volumes, it tends to recoil.

How does the pressure-volume curve of the lung differ from that of the thoracic wall?

The pressure-volume curve of the lung shows that the lung's transmural pressure is positive throughout its volume range, indicating the lung tends to retract. In contrast, the thoracic wall's transmural pressure is negative at lower volumes and becomes positive at higher volumes, indicating expansion and recoil, respectively.

What is the functional capacity volume in the context of lung and thoracic wall compliance?

The functional capacity volume is the amount of air remaining in the lungs after a relaxed exhalation. At this point, the transmural pressures of both the lungs and thoracic wall balance out, and the system is at rest.

What role do the respiratory muscles play during inspiration?

During inspiration, the respiratory muscles contract to expand the thoracic cavity and allow air to flow into the lungs, especially after reaching the functional capacity volume.

Why is it important to study the compliance of both the lungs and the thoracic wall?

Studying both the lung and thoracic wall compliance is crucial because changes in either can impact the overall respiratory system. For example, conditions like obesity or pneumothorax alter the system’s compliance and affect ventilation.

How can the compliance of the thoracic wall affect overall ventilation?

Changes in the compliance of the thoracic wall, such as in obesity, can restrict the ability of the thoracic cavity to expand and contract, thereby impacting the overall ventilation of the lungs and reducing respiratory efficiency.