Anatomy of chest wall and mechanics of breathing Flashcards
What does Boyle’s law state?
That the pressure exerted by a gas is inversely proportional to its volume.
What does Henry’s law state?
The amount of gas dissolved in a liquid is determined by the pressure of the gas and its solubility in liquid.
What does Dalton’s law state?
The total pressure of a gas mixture equals the sum of the pressure of the individual gases.
What does Charles’ law state?
The volume occupied by a gas is directly proportional to the absolute temperature.
What is the name given to the space between the lungs and chest wall?
Pleural cavity.
Describe the visceral membrane.
It is the aspect of the pleural membrane which covers the lungs.
Describe the parietal membrane.
It is the aspect of the pleural membrane which covers the inner surface of the thoracic cavity.
Is intrapleural pressure always positive or negative?
Negative.
Which muscles are used during inspiration?
External intercostal muscles and diaphragm.
Which muscles are used during expiration?
Internal intercostal muscles and abdominal muscles during severe respiratory load.
Which nerve supplies the diaphragm and which spinal levels does it flow out of?
The Phrenic Nerve supplies the diaphragm. (C3, C4, C5).
Describe a mechanism of asthma.
Over-constriction of bronchial smooth muscle.
What is a pneumothorax?
When the pleural cavity is opened. V bad; lung could collapse.
What are the three types of pressure exerted on the thoracic cavity?
Alveolar, intra-pleural (always negative) and transpulmonary.
Why is intrapleural pressure always less than alveolar pressure?
During expiration elastic recoil of the chest wall which allows the lungs to return to the normal size. This compresses alveoli, increasing alveolar pressure.
