Lung Volume Measurement and Indications of Pathology Flashcards
What is the device used to measure lung volume?
Spirometer
What are the 4 volumes that can be measured in the lungs?
- Tidal Volume
- Inspiratory Reserve Volume
- Expiratory Volume
- Residual Volume
What is tidal volume?
Normal volume of air inhaled and exhaled
-500ml
What is inspiratory reserve volume?
Extra volume inhaled on top of the normal tidal volume
What is the expiratory volume?
Extra volume you can get out after you normally exhale on top of the tidal volume
What is residual volume?
Left over volume that never leaves the lung
hard to measure
What is the total lung capacity?
How much volume the lungs can hold in total
-including all 4 volumes
What is the vital capacity?
3/4 volumes without taking residual volume into account
What is the Forced Vital Capacity?
Breath in and out as fast as you can, forcing it out
-volumes with vital capacity should be the same
What is the Forced Expiratory Volume/1sec?
How much air they expired in one second when they forced the air out as fast as possible
What is a normal FEV1/FVC ratio?
80% of air coming out in one second is normal
What makes an obstructive respiratory problem show up on a graph?
FEV1 is shortened
-takes them a long time to exhale all the air
What are characteristics of obstructive diseases?
Airway Inflammation
Airway Hyperresonpnsivness
Outflow Problems
-narrows airway
what are 3 obstructives diseases?
Asthma
Chronic Bronchitis
Emphysema
Characteristics of Asthma?
Spasms in airways (smooth muscle constricting) triggered by pollution, exercise, allergies
-contract when they aren’t supposed to
Characteristics of Chronic Bronchitis?
Excessive mucus and inflammation in the airways triggered by smoking
Characteristics of Emphysema
Walls between alveoli break down creating large air sacs triggered by smoking
Why is wall breakdown in the alveoli from emphysema bad?
Elastin breakdown results in losing the collapsing force that helps expel air
- lungs are too compliance but they can’t exhale
- decreases area for gas exchange
What makes a restrictive respiratory problem show up on a graph?
FVC is lower
-can blow out most of the air in the first second but there wasn’t much air in the lung to begin with
What are characteristics of restrictive diseases?
Difficulty filling the lungs
Less air to exhale
What is Pulmonary Fibrosis?
When scar tissue forms on the alveoli and other lung tissue (pollution, asbestos, coal) causing the lungs to become less compliant
Why does scar tissue impact compliance?
Scar tissue is not elastic, being attached to other eleastic tissue restricts movement. Decreasing compliance
How does Pulmonary Fibrosis affect gas exchange?
Scar tissue is a lot thicker than regular type 1 cells in the alveoli. Larger barrier that the O2 and CO2 molecules need to pass through, decreasing gas exchange
