Lecture #8 Flashcards
Major Functions of Respiration
- Gas Exchange
- Communication
- Olfaction: sense of smell
- Acid-Base Balance
- Blood and lymph flow
Pulmonary Ventilation is:
Consist of repetitive cycle of inspiration (inhaling) and expiration (exhaling)
Respiratory Cycle
one complete inspiration and expiration
- flow of air in and out of the lung depends on pressure different inside and outside the body
The flow of a fluid is proportional to ..
the pressure different
the flow of a fluid is inversely proportional to
the resistance
Boyle’s Law
at a constant temperature, the pressure of a given quantity of gas is inversely proportional to its volume
What pulls air into the lungs
the lung volume↑,the internal pressure of the lungs(intrapulmonary pressure) ↓ and pulls air into the lungs
What pushes are out of the lungs?
If the lung volume↓,intrapulmonary pressure↑and pushes are out of the lungs
Intrapleural Pressure causes…
lungs to expand with expansion of the thoracic cage
Intrapleural pressure: is define as negative pressure that exists between the two pleural layers
Resistance influenced by:
- Diameter of the bronchioles Bronchodilation: increase in diameter of the bronchus, thus increases airflow
Brochoconstriction” decrease in diameter of bronchus, thys decrease air flow
- Pulmonary Compliance
- ease so lungs can expand
- decrease by lungs disease which the lungs are stiffened by scar tissue
What is the Iron Lung
Device used for patients with Polio, it is artificial ventilation
changes pressure on lungs so inspiration and expiration can occur
Decreased pressure = inspiration
Increased pressure = expiration
Spirometer
device that recaptures expired breath
- records rate and depth of breath, speed of expiration and rate of oxygen consumption
Spirometry
the measurement of pulmonary function
used in determining restrictive or obstructive lung disorders
Tidal volume (TV)
volume of air inhaled and exhaled in one cycle of breathing (~500 mL)
Inspiratory reserve volume (IRV):
air in excess of tidal volume that can be inhaled with maximum effort
Expiratory reserve volume (ERV):
air in excess of tidal volume that can be exhaled with maximum effort
Residual volume (RV):
air remaining in lungs after maximum expiration
Vital capacity (VC) (ERV + TV + IRV):
total amount of air that can be inhaled and then exhaled with maximum effort
Inspiratory capacity (IC) (TV + IRV):
maximum amount of air that can be inhaled after a normal tidal expiration
Functional residual capacity (FRC) (RV + ERV):
amount of air remaining in lungs after a normal tidal expiration
Total lung capacity (TLC) (RV + VC):
maximum amount of air the lungs can contain
Pulmonary Aveoli
- Squamous (type I) alveolar cells:
thin, rapid gas diffusion - Great (type II) alveolar cells: repair alveolar epithelium and secretes pulmonary surfactant that coast the alveoli
- Alveolar macrophages (dust cells): keep alveoli free from debris
Composition of air
78.6% nitrogen
20.9% oxygen
0.04% carbon dioxide
0-4% water vapour
Dalton’s Law
total atmospheric pressure is the sum of the contributions of the individual gases