Smart Sparrow Prac 5: Resp histology and pathology

Question 1

What are clara cells?

Answer 1

The name given to goblet-like cells in the smaller airways (terminal and respiratory bronchioles).

Question 2

What is the most common causative organism of lobar pneumonia?

Answer 2

Streptococcus pneumoniae

Question 3

Which of the following are ‘typical’ pathogens that cause bronchopneumonia?

• Haemophilus influenzae
• Aspergillus spp.
• Influenza virus
• Klebsiella pneumoniae
• Staphylococcus aureus
• Mycoplasma pneumoniae

Answer 3

Haemophilus influenzae, Klebsiella pneumoniae, Staphylococcus aureus

Note: both lobar and bronchopneumonic (and mixed) patterns of pneumonia involve an acute inflammatory response with purulent exudate in alveolar spaces. Some bacteria e.g. Strep. pneumoniae can cause either pattern.

Mycoplasma pneumoniae and viruses typically cause an interstitial pattern of inflammation and the inflammatory infiltrate will predominantly be ‘mononuclear’, not ‘polymorphonuclear’.

Aspergillus may cause a variety of patterns of infection in the lung but is not a typical cause of bronchopneumonia. Aspergillus is a fungus and typically causes infection in those with asthma or immunosuppression.