Resp 3 Flashcards
What causes “pump handle” motion?
external intercostals of UPPER ribs and scalenes
What causes “bucket handle” motion?
external intercostals of LOWER ribs
What are some secondary muscles required during forced inspiration?
- sternocleidomastoid
- neck and back muscles
- upper respiratory tract muscles
What are some secondary muscles required during forced expiration?
- abdominal muscles
- internal intercostals and triangularis sterni
- neck and back muscles
Inspiratory muscles pull the _________ pleura away from the ________ pleura, _________ the volume of the intrapleural cavity and _________ the intrapleural pressure.
-parietal, visceral, increasing, decreasing
Intrapleural pressure is approximately….
-3 mmHg
At rest, there is a ________ intrapleural pressure due to elastic recoils of the lung _______ and chest wall _______.
negative, inwards, outwards
Increase in intrapleural volume due to inspiratory muscle contraction (and decrease in pressure) causes….
decrease in pressure to pull alveoli open, decreasing alveolar pressure and air flow; as alveoli fill with air, pressure begins to match atm. pressure and air flow stops.
pneumothorax
collapsed lung; if the sealed pleural cavity is opened to atmosphere, the bond holding lung to chest wall is broken
compliance
“stretchability”; degree of lung expansion is proportional to change in pressure
lung elastance (elastic recoil)
reciprocal of compliance; ability to resist being deformed
Increased compliance means ___________ elastance.
decreased (and vice versa)
pulmonary fibrosis
formation or development of excess fibrous connective tissue in the lungs; decreased compliance
emphysema
proteolytic enzymes secreted by leukocytes attack alveolar tissue weakening its walls and creating airway resistance; increased compliance
surface tension
measure of force acting to pull a liquid’s molecules together at an air-water interface
