Week 2 Lung defense and respiratory Load Flashcards
What are the main functions of the URT?
- Conduction of gas to LRT
- Humidifies and warms air
- Filters air
Liquid or solid particles suspended in air.
Diameter of such particles is important for the lung.
Aerosol
How many micrometres (μm) of aerosol pose the greatest threat to the lung?
<10 μm
Medium particles (1-3μm) are deposited in the airways via?
Sedimentation
Particles > 5-10μm are filtered where in the URT?
At the nasopharynx and the tracheobronchial tree
Particles that reach the alveoli are cleared by?
Phagocytosis (alveolar macrophages, neutrophils, monocytes, digested or moved up airway to mucociliary escalator)
- closure of this part of the URT prevents aspiration of foreign material (food and liquid) into the LRT
Epiglottis
Layer of the respiratory mucous which contains the periciliary, a thin and fluid like, and allows the movement of cilia
Sol layer - deeper layer
What is the mucociliary clearance?
- helps or is responsible in clearing airways of secreted mucous and trapped substances.
a layer of the respiratory mucous which is thick, gelatinous, and traps particles
Gel layer - superficial layer
This is what you call the movement of the secretions and apparatus for moving for moving it is called?
Mucociliary escalator
What is the 3 layers of the conducting airways?
Inner
- mucosa and submucosa
- mucous membranes
Middle
- smooth muscle
Outer
- adventitia (connective tissue)
It is compromised of 95% water, 3% glycoprotein, 1% lipid, 1% mineral (inorganic, electrolytes), and also contains IgA
Respiratory mucous
Phase of a cough which is dependent on air inspired
Inspiration Phase
Hair like projections from pseudostratified columnar epithelial cells
- none of this in the Alveoli
Cilia - beats with a whipping action
What are the factors that affect Mucociliary clearance?
- Age (as you get older = reduced cilial beat frequency)
- Sleep - has a depressant effect
- Exercise - results in greater MCC
- Gravity (posture)
- chemical irritations (smoke, dehydration)
- drugs
- High FiO2
- hypoxia and hypercapnia
A congenital disorder affecting the MMC which impairs cilial activity due to absence of contractile elements. Is associated with reduced fertility.
Immotile cilia syndrome (primary cilial dyskinesia)
A disease that affects the MCC, which makes the mucous thick and sticky, it is also due to abnormal chloride transport - thus leading to dehydration of mucous airways.
Cystic Fibrosis
Some other diseases that affect MCC
- bronchiestasis
- asthma
- chronic bronchitis
- a reserve clearance mechanism after MCC - it is also a protective mechanism for respiratory
Cough
A phase of cough wherein the glottis closes, muscles contract against glottis, there is a rise in abdominal pressure
Compressive phase
This is when airway will be compressed towards the mouth from the EPP
Expiratory airflow in airways in increased.
Dynamic Compression
The phase of cough wherein, glottis suddenly opens, rapid pressure drops in URT
Expiratory phase
What is Equal Pressure Point (EPP)
- point in which pressure in alveoli and pleura are equal
Note: EPP moves closer to alveoli at lower lung volumes
