Respiratory Physiology Flashcards
External Respiration
Integration of the respiratory and CVS systems allowing movement of gases between air and the cells
Normal respiratory rate
10-20 breaths a minute
Patency
How open an airway is
Alveoli
Site of gas exchange in the lungs
Type I pneumocyte
Simple squamous epithelium for gas exchange
Type II pneumocyte
Produces surfactant (reduces surface tension)
Type of epithelium in respiratory tract
Pseudo-stratified columnar epithelium that is ciliated and glandular
Goblet cells
Produce mucous
Boyle’s Law
Pressure exerted by a gas is inversely proportional to its volume
Henry’s Law
Amount of gas dissolved in a liquid is determined by pressure of gas and solubility in the liquid
Dalton’s Law
Total pressure of a gas mixture is the sum of the pressures of the individual gases
Alveolar Pressure
Pressure inside the lungs
Intra-pleural pressure
Pressure inside the pleural cavity (always negative)
Trans-pulmonary pressure
Difference between alveolar pressure and intra-pleural pressure
Muscles of Inspiration
Diaphragm and external intercostals
Muscles of expiration (forced)
Internal intercostals and abdominal muscles
Accessory muscles
Scalene and sternocleidomastoids
Tidal Volume
Volume of air breathed in and out of lungs at each breath
Expiratory Reserve Volume
Maximum volume of air which can be expelled from lungs at end of normal expiration
Inspiratory Reseve Volume
Maximum volume of air which can be drawn into the lungs at end of normal inspiration
Residual Volume
Volume of gas in the lungs at the end of a maximal expiration
Vital Capacity
Tidal volume + IRV + ERV
Total lung Capacity
Vital capacity + reserve volume
Inspiratory capacity
TV + IRV
Functional Residual Capacity
Expiratory reserve volume + residual volume (amount of air normally in lungs at end of expiration)
Anatomical dead space
Volume of gas occupied by the conducting airways and not available for gas exchange
Volume
Amount of air moved in a single expiration