Respiratory Physiology 2 Flashcards
Pneumothorax
recoil forces of lung and chest wall
Quiet Inspiration
- inspiratory muscles contract
- thoracic volume INC (lungs stretch)
- Intrapulmonary pressure DEC
- air goes into lungs until pulmonary pressure = atmospheric pressure
Forced Inspiration
- scalenus and sternocleidomastoid
- more thoracic volume
- less thoracic pressure
- larger pressure gradient
- more air flow in
Quiet Expiration
- Passive process
- inspiratory muscles relax
- elastic lungs recoil
- less thoracic volume
- more alveolar pressure
NO MUSCLE INVOLVEMENTS OTHER THAN RELAXATION
Forced Expiration
- abdominal and intercostals
- more decrease in thoracic volume and pressure
- more gradient
4 factors influencing pulmonary ventilation
- AIRWAY RESISTANCE
- ALVEOLAR SURFACE TENSION
- LUNG COMPLIANCE
- ELASTIC RECOIL
Airway resistance
- influences pulmonary ventilation
- radius of bronchioles
F = P/ R
Epinephrine dilates bronchioles
Alveolar Surface Tension
- surface tension
- attracts liquid molecules together
- resist force that tries to increase SA of liquid
Surfactant
detergent like lipid and proteins, produced by TYPE II ALVEOLAR
- less surface tension
- less chance of collapse
Lung Compliance
- expandability of lungs
- normally high
Diminshed by:
- nonelastic scar tissue
- reduced production of surfactant
- less thoracic cage movement
Elastic Recoil
- lungs rebounding
2 factors:
1. connective tissure in lungs (collagen/elastin)
- Alveolar Surface tension (reduces tendency of alveoli to recoil)
Tidal Volume
500 mL
air entering or leaving lungs in single breath
Residual Volume
1200 mL
maximal expiration, air that stays in the lung
Vital Capacity
4500 mL
maximum volume out in a single breath after maximum inspiration
Dead Space
- inspired air - does not change gas exchange
Alveolar dead space
no gas exchange bc of collapse or obstruction