Biological role of respiration, histology and defence mechanisms Flashcards
What are the three principle compartments of the respiratory system
Conduction Zone: Conditioning of inhaled air
Respiratory Zone: Site of gas exchange
Musculo-elastic ventilation appararatus: Drives ventilation
What are airways kept open by
Either bony or cartilaginous scaffolds
What is the role of turbinate bones in the nasal cavity
Form narrow passageways that create turubulence, driving air in and out of sinuses which enhances surface to air volume ratio
What adjusts the temperature and moisturises air
Large venous plexus in the submucosa
Where does mucus lie in the nasal cavity
Lining all the way to the terminal bronchioles
What is the epithelium of the respiratory tract
respiratory type
What do the veins of venous plexus in mucosa do
Mediate exchange of moisture with the air; their filling status also regulates the flow of air through the nasal cavity
What is the role of the olfactory epithelium
Conveys the sense of smell
What does the respiratory epithelium consist of
-Pseudostratified, ciliated epithelium of varying thickness with mucous producing goblet cells
What is the bronchial lumen bordered with
Respiratory epithelium
What does the bronchus contain
Incomplete ring of smooth muscle located between the epithelium and cartilage
Cartilage on its wall
What does a bronchioles not have
Cartilage on its wall
How does a bronchiole differ from a bronchus
- Fewer goblet cells
- Complete ring og sooth muscle surrounding the epithelium
- No submucosal glands
What does the epithelium of the smaller bronchiole become
Cuboidal
What does the epithelium of the smaller bronchioli consist of
Ciliated cells as well as non-ciliated club cells
What is the role of club cells
Have a protective role - generate serous secretions
How does bronchioli differ to bronchi
Ratio of muscle ring thickness to luminal diameter is higher as bronchiolar constriction induces high airway resistance
What does the connective tissue of the alveoli and the lower airways contain
Numerous elastin fibres
Where is the blood supply to the alveolar capillary network from
Pulmonary circulation
Where do the bronchi have their own blood supply from
Aorta (bronchial circulation)
What is the role of a surfactant
reduce surface tension which allows the expansion of the lung and prevents the collapse of the alveoli
What produces surfactant
type 2 pneumocytes
What are the pleural walls covered with
Simple squamous epithelium
What do the elastic fibres in the interstitial spaces in the alveoli do if the pleural cavity is pierced
Cause a lung to shrink
Where are the lymph vessels of the lung’s drainage system found
-Where do they drain
In septa next to the vessels of the pulmonary circulation
-Drain into major lymph nodes along the trachea
