What are the functions of the nasal cavity?
cleans, warms, moistens air
How does cold air trigger asthma?
Breath through mouth > cold air to lungs > stim. bronchospasm
What is deglutition apnoea?
Can’t swallow + breath at same time
Describe the structure of the trachea
- Lumen kept open by 20c shaped hyaline cartilage
- Gaps between rings filled with trachealis = bundle of smooth muscle + fibro-elastic tissue
- Epithelium = pseudo-stratified columnar
Describe the structure of the bronchus
- Circular layer of smooth muscle
- Less cartilage - does not completely encircle lumen
- Epithelium = tall columnar + some goblet cells
Describe the structure of the bronchioles
- No cartilage but smooth muscle layer doesn’t completely encircle lumen
- Epithelium = ciliated columnar in larger bronchioles, non-ciliated in smaller
- No goblet cells but Clara cells = secrete surfactant
What is Kartagner syndrome?
Cilia loose ability to function = fluid retention = pathogens + infection
What is the pulmonary interstitium?
- Area of lung between alveolar epithelial + capillary endothelial basement membranes
- Parenchymal part = airways structure
- Centrilobular part = bronchioles structure
What does PS innervation of lung cause?
Bronchoconstriction
Vasodilation
Mucous gland + goblet cell secretion
What does sympathetic innervation of lung cause?
Bronchodilation
Vasoconstriction
Modulate cholinergic transmission
Describe inhalation
- External ICM contract
- Rib cage up + out
- Diaphragm contracts = flat
- Low pressure, air drawn in
Describe exhalation
- External ICM relax
- Rib cage down
- Diaphragm relaxes = dome
- Volume decreases, pressure increases, air forced out
Define total lung capacity
Vol at max inflation
Define tidal volume
Air in + out during quiet breathing
Describe functional residual capacity
Vol left at end expiratory position (normal breathing)
Describe vital capacity
Deepest expiration following deepest inhalation
Describe residual volume
Vol air after max expiration
Describe inspiratory reserve volume
Max vol inhaled from end-inspiratory level
Describe expiratory reserve volume
Max vol exhaled from end-expiratory level
What is compliance?
Change in vol/ Change in pressure
What increases lung compliance?
Surfactant increases compliance by reducing surface tension
What causes neonatal respiratory distress syndrome?
Low amount of surfactant
What is subglottic stenosis?
Narrowing of airway below vocal cord and above trachea
What is surfactant
Lipoprotein complex secreted by type 2 alveolar epithelial + Clara cells
