Lung Mechanics And Ventilation Of The Lungs Flashcards
What is the tidal volume?
500mL
On average 7ml/kg
What 2 muscles are involved in quiet respiration?
Diaphragm and external intercostals
What is the purpose of pleural fluid?
Creates surface tension and a pleural seal allowing for lung expansion with the thoracic cavity.
What is resting expiration level>
Amount of air in lungs when you have exhaled to a comfortable level
How do you calculate total pulmonary ventilation?
TV x resp rate
What is physiological dead space made of?
Anatomical dead space and alveolar dead space
When does surfactant start to be produced in the foetus and by which point is it in sufficient quantities?
24-28 weeks
35-36 weeks
What are some symptoms of respiratory distress syndrome?
What is the treatment given to the baby?
Tachypnoea Intercostal recession Grunting nasal flaring Cyanosis
Surfactant replacement via endotracheal tube with O2 and assisted Ventilation
How is the fact that tubes of lower pressure having higher resistance to flow countered in the lungs’ small airwarys (pouseille’s law)?
Parallel arrangement compensates for this increase in their individual resistance
What happens to small particles 1-5um in size if they become trapped in the lungs?
carried down to alveoli where they are phagocytosed and drain into the lymphatic airways
What portions of the respiratory tract are lined with simple columnar epithelium?
What other cells are found there?
Bronchioles and terminal bronchioles
Clara cells
Give 2 differences in the histology of a bronchus and a bronchiole.
No subepitelail cartilage
No glands
What’s will occur to chest expansion in interstitial lung fibrosi?
Bilaterally reduced
What is resorption collapse?
Airway obstructed
Distal to airway air is absorbed back into blood stream at a rate faster than it is replaced leads to volume loss in the distal segment.
