Mechanics Of Breathing Flashcards
Where is the diaphragm muscle
Floor of the thoracic cavity
Contractions of what muscles allow for the inspiration and expiration
Intercostal and diaphragm muscles
When the muscles contract they 1) pull what and how 2) volume of thoracic cavity what
1) pull ribcage upwards and outwards 2) volume of thoracic cavity increases
As the volume of the thoracic cavity increases, the pressure within
Decreases
Decrease of pressure in thoracic cavity causes what
Negative pressure
Negative pressure causes what
Air to be pulled into the lungs
What pushes the air out of the cavity
Positive pressure
Within the thoracic cavity, there are 2 secondary cavities called what
Pleural cavities
Pleural cavities are formed by
Serous membrane called the pleurae
Visceral pleura lines what
Each lung
Parietal pleura lines what
Thoracic wall
Between the 2 membranes is what
Pleural fluid
Pressure in thoracic cavity decreases, which causes a pull on what which promotes what
Pull on the pleural cavities which further promotes expansion of the lungs
At rest, intrapleural pressure in pleural cavities is always slightly what than the atmospheric pressure within alveoli
Slightly less, approx minus 4mmHg
Atmospheric pressure is referred to as
Intra pulmonary
The imbalance between the intrapleural and intra pulmonary pressure prevents what
Collapse of the alveoli and lungs
Pleurisy or pleuritis is what
Inflammation of the pleurae that line the pleural cavities due to pneumonia or lung infection
Atelectasis is what
Lung collapse
Atelectasis occurs when
Air enters the pleural cavity via chest wound or rupture of visceral
Presence of air in intrapleural space is what
Pneumothorax
The intercostal muscles are what
Muscles between the ribs
