2. Mechanics of breathing

Study Guide

What muscles are involved in normal, quiet inspiration?

Do the muscles contract of relax to facilitate inspiration?

What muscles become involved in active inspiration?

Do they contract or relax

Upon contraction of the muscles of inspiration, what happens to thoracic volume?

What forces are involved in quiet expiration?

Do the muscles contract or relax to facilitate expiration?

How is elasticity of the lungs involved in expiration?

What muscles become involved in forced expiration?

What happens to thoracic cavity volume to facilitate expiratiion?

What happens to pressure as volume increases?

What happens to pressure as volume decreases

How does this concept of Boyle’s Law apply to the mechanics of breathing?

What is intrapulmonary (intra-alveolar) pressure (where)?

What is intrapulmonary pressure between breaths

What must happen to intrapulmonary pressure between breaths

what must happen to intrapulmonary pressure for inspiration to occur? How is this accomplished?

What must happen to intrapulmonary pressure for expiration to occur? How is this accomplished?

What (and where) is intrapleural pressure and what factors contribute to this pressure being negative?

What does transpulmonary pressure measure?

What is the difference between elastance and compliance?

In terms of emphysema, is compliance increased or decreased?

In terms of emphysema, is elastance increased or decreased?

In pulmonary fibrosis, is compliance increased or decreased?

What happens to intrapleural pressure in pneumothorax (EX: knife wound damages the parietal pleura)? In terms of pressures, why can’t the lung inflate?

What are the surfactants made up of and where are they produced in the respiratory system?

How does surface tension affect the respiratory system and how does surfactant affect surface tension?

How do surface tension and surfactants play a role in conditions such as neonatal respiratory distress syndrome?

What must air overcome in order to flow into/out of the lung?

How is airway resistance calculated?

What factors affect airway resistance in the lungs?

Where is airway resistance highest?

What happens to intra-airway pressure in a normal airway during quiet expiration?

What happens to intra-airway pressure in a normal airway during forced expiration?

What happens to intra-airway pressure in a patient with emphysema?

What does a normal flow volume loop look like

Aspects of the FEV1/FVC testing. What is a normal ration or percentage?

What are the characteristics of restrictive and obstructive disease?

What happens to different lung volumes during obstructive (emphysema) disease?

What happens to different lung volumes during restrictive disease?

What FEV1/FVC ratio or percentage characterizes obstructive disease?

What FEV1/FVC ratio or percentage characterizes restrictive disease?

What does flow volume loop look like for someone with emphysema?

What does a flow volume loop look like for someone with emphysema?

What does a flow volume loop look like for someone with emphysema?

What does a flow volume loop look like for someone with fibrosis?