Lecture10: Regional Ventilation Flashcards
What is used to describe the relationship between airflow, pressure gradient and resistance?
Ohm’s law
Which instrument is used to measure airflow?
Pneumotachograph
What type of airflow does Pouiseullie’s law only apply to?
Laminar Flow
What does Pouiseuille’s law show?
That airway resistance is inversely proportional to the radius
If airflow becomes turbulent, what needs to be increased to maintain airflow?
The pressure difference
Total airways resistance becomes……during inspiration?
Less
What is the Expiratory Break?
When the vocal folds reflexly open during inspiration and close during expiration
What is the major site of airway resistance?
The medium sized bronchi
What protects the medium sized bronchi from collapse?
The incomplete rings of cartilage
What is the Silent Zone?
The peripheral airways that contribute little resistance
What are the Most important parts of the bronchial tree in terms of the physiological control of airway resistance?
The Smaller bronchi and bronchioles
Characteristics of smaller bronchi and bronchioles?
No supporting cartilage, relatively small and resistance is influenced by broncho-motor tone
What muscle type are smaller bronchi and bronchioles made of?
Smooth muscle
What is the most important determinant of flow in a tube?
The radius
What causes Radial Traction?
Elastic fibers of surrounding alveoli
