Ventilation and Pulmonary Function Assessment Flashcards
What events cause inhalation and exhalation?
Rib cage expands as rub muscles contract (air inhaled)-Inhalation diaphragm contracts (moves down)
Rib cage gets smaller as rib muscles relax (air exhaled)-Exhalation- Diaphragm relaxes (moves up)
What is Boyle’s law?
Law states pressure of gas in closed container is inversely related to volume of the container. 760 mm pressure at sea level. 1 liter-1 atm pressure. But decrease volume in container to 1/2 liter-2 atm pressure. Differences in pressure caused by changes in lung volume forces air into and out of lungs during inhalation/exhalation.
Inspiration (inhalation): The process of breathing in. This is an ______ process.
active
Muscles of inhalation (inspiration)
Main:Sternocleidomastoids, external intercostals, diaphragm. Assessory: Scalenes. Lungs have 70m2 of surface area
Air flows from region of ____ pressure to _____ pressure, inspiration takes place. What number?
higher, lower. 760 to 758 mmHg
Typically exhalation is a _______ process which means what?
passive. No muscle contractions are involved
In exhalation air flows from region of ____ pressure (lungs) to region of _____ atmosphere. What does the alveolar pressure increase to?
higher, lower.
762mmHg
T/F- Normal expiration takes place because of the pressure differences?
True
T/F-The pressure of the lungs is less than the pressure of the atmosphere?
False. Pressure is greater than the atmosphere.
When would exhalation become an active process (when muscle contractions are involved) and which muscles would be used if it did?
Active in childbirth, playing sports.
Muscles of expiration: diaphram, internal intercostals, abdominal recti. (these are all used in forceful breathing aka active exhalation)
What is compliance?
Refers to how much effort is required to stretch the lungs and thoracic wall
Lungs resist expansion at what compliance?
Low
Lungs and thoracic wall expand easily at what compliance?
High
Lungs usually have what _____compliance and expand easily cause of elastic fibers and surfactant
High
If low on surfactant lungs are ______ compliance
Low
What is dead space?
Volume of air that doesn’t reach the alveoli and not involved in gas transfer
Men have ____ lung volume then women. What are typical normal lung volumes? What is tidal volume?
Larger. Tidal volume is 500ml for both female and male.
T/F- Small alveoli would be at greater risk of collapse without surfactant?
True
Which type of cells extract surfactant? What is the composition of surfactant? At how many weeks does it start to form?
Type ll alveolar cells.
90% phospholipid, 10% protein
30 weeks
What can cause decreased compliance?
Pathologic conditions (TB (caused by myobacteria), pulmonary edema, paralysis of intercostal muscles, surfactant deficiency in premature infants)
As avioli expand compliance _______
decreases
What is tension pneumothorax?
Occurs when a closed pneumothorax creates positive pressure in the pleural space that continues to build. Pressure is transmitted to the mediastinum (heart & great vessles) SVC/IVC are off, need chest tube to affected side. Breath sounds low, pre load filling & contraction of heart affected. HR goes up.
What is atelectisis?
Complete alveolar collapse.Atelectasis may be the result of a blocked airway (obstructive) (add more?)
What is the law of laplace?
Pressure is directly proportional to surface tension and inversely proportional to radius of alveolus. (Small alveoli are at great risk of collapse bc of this). Alveoli has natural tendency to recoil after ….
______ surface tension allows alveoli to readily fill with gas
Decreased
Title volume
Amount of air inhaled or exhaled with each breath under resting conditions
Inspiratory reserve volume
Amount of air that can be forcefully inhaled after a normal tidal volume inhalation
Expiratory reserve volume
Amount of air that can be forcefully exhaled after a normal tidal volume exhalation
Residual volume
Amount of air remaining in the lungs after forced exhalation
Total lung capacity
Maximum amount of air contained in lungs after a maximum inspiratory effort
Vital capacity
Maximum amount of air that can be expired after a maximum inspiratory effort
Inspiratory capacity
Maximum amount of air that can be inspired after a normal expiration
Functional residual capacity
Volume of air remaining in lungs after a normal tidal volume expiration
What causes COPD?
Chronic bronchitis and emphysema
