Physiology Flashcards
Which of the respiratory processes is active?
Inspiration
Which of the respiratory muscles is passive?
Expiration
What are the muscles of inspiration?
The diaphragm, external intercostal muscles and accessory muscles
What are the muscles of expiration?
The abdominal muscles and the internal intercostal muscles
What is compliance?
The force required to distend an elastic body at rest
What is elasticity?
The force required for an elastic body to return to rest
What diseases decrease lung compliance?
Pulmonary fibrosis
Pulmonary Edema
Atelectasis
What disease increases lung compliance?
Emphysema
What causes the lung to return to residual volume after exhaling?
Elastic recoil and surface tension
What is surface tension?
The amount of energy required to increase a liquid’s surface area
What is surfactant made up of?
Phospholipids (90%)
Proteins (10%)
Calcium ions
Lamellar bodies
What are the properties of surfactant?
- Reduce surface tension, increasing compliance and reducing the work of breathing
- Promote alveolar stability, optimising ventilation perfusion
- Avoid transudation of liquid within the alveoli
- Immunologic properties due to the presence of aporproteins
What is the function of the pleura?
It produces pleural fluid to lubricate the pleural space and limit respiratory friction
How does air travel in the respiratory system?
Trachea > Mainstem bronchi > Lobar bronchi > Segmental bronchi > Terminal bronchioles > Respiratory bronchioles > Alveolar ducts > Alveoli > Acini
How is alveolar ventilation measured?
Through CO2 of exhaled air
