Lecture 3: Upper airways Flashcards
Describe the epithelium of the nares//conchae:
3 Conchae (turbinet bones)
Resp epithelium
- Ciliated
- Goblet cells
Describe the epithelium of the pharynx:
- Some stratified epi b/c food (3 divisions) and resp epithelium
What is the function of the respiratory epithelium?
- Clean (Filter)
- Humidified
- Warm
What are the anatomical divisions of the respiratory system?
Upper airways: Nasal cavity, pharynx, larynx
Lower airways: Trachea, bronchi, bronchioles, respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
What are the functional divisions of the respiratory system?
Conduction zone: Nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
Respiratory zone: Respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
How many times does the bronchiole tree divide before the resp. zone?
~17 times, suggested to be clinically important
What are the cells of the respiratory tract?
Psuedostratified columnar ciliated epithelium Goblet cells Club (clara) cells Type 1 pneumocytes (At1) Type 2 pneumocytes (AT2) Macrophages
Write some notes on pseudostratified columnar ciliated epithelium location and function:
Located: Conducting Zone: Nasal cavity, nasopharynx, trachea, bronchi (large)
Function: Ciliated-> Movement of mucous, motile cilia
Write some notes on goblet cells location and function
Location: Most of conducting zone; Nasal cavity, nasopharynx, trachea, bronchi (large)
Function: Mucous, not ciliated
Write some notes on club cells location and function;
Location: Bronchioles, cuboidal ciliated epithelium too
Function: Provides liquid lining (finer mucous), secrete watery substance -> Antimicrobial properties
Write some notes on type 1 pneumocytes location and function:
Location: Respiratory zone
Function: Squamous, (like egg), thin air-blood barrier
Write some notes on type 2 pneumocytes location and function:
Location: Respiratory zone, secrete surfactant
Write some notes on alveolar macrophage location and function:
Location: Alveoli
Function: Defence, wandering- can move between b/w alveoli
Whats the connective tissue of the respiratory system?
Cartilage
Elastic fibres
Collagen
Smooth muscle
Where is cartilage found in the respiratory tract and whats its function?
Found: Trachea and bronchi
Function: Airways open
Describe elastic fibres location and function in the respiratory tract?
Found: Everywhere
Function: Ventilation - Impacted by COPD (Obstruction_
Describe collagen fibres location and function:
Location: Everywhere
Function: Support + Diaphragm (restrictive i.e CF)
Where is SM found in the Respiratory tract and what is its function?
Found: Trachea to the alveolar ducts
Function: Most important site is bronchioles, controls airflow
What are the two sources of mucous in the respiratory tract?
- Goblet cells
2. Seromucous glands
Where are seromucous glands found and what are their function?
Seromucous glands are found in the submucosa of the nasal cavity, trachea, bronchi
Describe the mucous layer of the airways?
Biphasic
- Serous watery (Sol layer) in which cilia beat
and
- Visoeleastic or gel layer, above
(mucociliary escalator)
What other liquid layers are in the respiratory tract?
Bronchiole and respiratory zone airway secretions are compromised of club cell secretions and surfactant.
Whats the overall function of the conducting zone?
- To prepare the air for gas exchange
2. To get air into the respiratory zone as efficiently as possible
What happens to mucous with smoking?
Smoking kills of motile cilia therefore theres thicker mucous (gel layer)
