Respiratory System - ESA 1 Flashcards
Membranes found in the respiratory system and where are they found?
Mucous membrane
Lines the conducting portion of the respiratory tract
Bears mucus secreting cells to varying degrees
Serous membranes
Lines the pleural sacs which envelope each lung
How is the lung protected?
1) Visceral pleura lines the outside of the lung
2) Lubricating fluid inside the pleural cavity (thin layer separating the visceral and parietal pleura)
3) Parietal pleura lines the outside of the pleura cavity
How does the lubricating fluid in the pleural cavity protect the lung?
Reduces friction, allowing the pleura to slide easily during breathing
Provides surface tension to prevent the lung recoiling and collapsing
What can fill the pleural cavity and what is the medical term for each?
Air - pneumothorax
Blood - haemothorax
Pus - empyema
Watery transudate - pleural effusion
Outline of what to do if fluid fills the pleural cavity?
Drain fluid by inserting a wide-bore needle through (typically) the 7th intercostal space posteriorly (under ultrasound guidance)
Procedure of draining fluid from the lung (Specifics)
Insert a wide-bore needle a fraction above the superior border of the lower rib of the 7th intercostal space
What do you try to avoid when draining fluid from the lung and where are these structures?
Avoid intercostal nerves and vessels
Run along the inferior border of each rib
Why is a needle not inserted below the 7th intercostal space?
Danger of penetrating the diaphragm
What holds the parietal and visceral pleura together so the ling can expand and contract?
Vacuum creates a negative pressure in the pleural space
What are the intrapleural pressures during inspiration and exhalation?
Inspiration = -8cmH2O Exhalation = -4cmH2O
What is Boyle’s law?
When the volume of a container increases the pressure decreases
When the volume of a container decreases the pressure increases
What is LaPlace’s law?
Gas will move from a smaller containing sphere to a larger sphere
P = (2pi)/r
Role of surfactant in inspiration and expiration
Inspiration: move apart to allow alveoli to expand
Expiration: move together when the lungs contract, which reduces surface tension
Pressure at the end of exhalation?
Atmospheric pressure (0cmH2O)
What can intrapleural pressure fluctuate to when breathing?
4cmH2O less than the intrapulmonary pressure
