Respiratory Physiology 1 Flashcards
What is positive pressure breathing?
Creating positive pressure in relation to the lungs, forcing air into the lungs
What is negative pressure breathing?
Decreasing pressure relative to atmosphere, causing gradient, causing air to be drawn in
Pip
Intrapleural pressure aka intrathoracic pressure
Palv
Alveolar pressure
Ptp
Transpulmonary pressure (Palv-Pip)
Patm
Atmospheric pressure
Steps of inspiration
1) Ribcage up and out
2) Diaphragm go flat - contract
3) Parietal membrane pull out, visceral pleural pulled out too
4) Pip decreases as volume increases
5) Increases difference between Palv and Pip which increases Ptp
6) Bigger the Ptp the greater the enlargement of the alveoli
7) Alveolar volume increases
8) Palv decreases
9) Change in pressure between atmosphere and alveoli, air drawn in to increase pressure
Steps of expiration
1) Relaxation of inspiratory muscles, chest wall decrease, and recoil back in
2) Space between pleural decreases
3) Difference between Pip and Palv decreases
4) Ptp decreases
5) Alveolar wall recoils, alveolar volume decreases
6) Palv increases
7) Change in pressure between atmospheric and alveolar
8) Force air out of lungs
9) Lung tissue recoilnd help alveoli go to normal size
What is pneumothorax?
Air leaks into the space between the lung and chest wall
The air pushes on outside of the lung and causes it to collapse/partially collapse
Now natural tendency of lung to collapse- elastic recoil of alveoli
What is resistance?
Resistance of respiratory tract to airflow during inspiration and expiration
What is compliance?
Ability of lungs to stretch and expand
Why are children at greater risk of an obstructive disease?
1) Smaller airways
2) Higher resting respiratory rates
What is an obstructive disease?
Increased resistance by a narrower airway
What is a restrictive disease?
Decreased compliance, decreased ability of lungs to expand
What is fibrosis?
Thickened stiff tissue which makes it more difficult for lungs to work properly
