Pathology of Pulmonary Infection Flashcards
What is a primary pathogen?
A very pathogenic organism that will infect everyone regardless of health
What is a facultative pathogen?
Will be unable to infect very healthy people with strong immune systems
What is an opportunistic organism?
One that can only infect severely immunocompromised individuals
What two things are taken into consideration when working out a persons ability to resist pulmonary infection?
- Immune system state and state of frontline defences
- Age of patient
What is acute epiglottis?
Inflammation that leads to swelling of the epiglottis that can block the airway
What bacterium is responsible for acute epiglottis?
- Group A beta haemolytic streptococci
What bacterium can cause a common secondary infection following epiglottis?
Haemophilus Influenza
What is the main aspect of respiratory defence?
Macrophage-mucociliary escalator system
What role do macrophages have in the respiratory system?
- Endocytose foreign antigens
- Transport indigestible antigens to the mucociliary escalator to transport them out of the lungs
What other system can macrophages use to transport material out of the lungs?
Lymphatic
How does the mucociliary escalator move mucous out of the lungs?
- Cilia beat in a coordinated fashion to move material out of the lungs
What is the coughing reflex?
A rapid movement of air that carries material from the airways out of them
What happens if the mucociliary elevator fails?
Things breathed into the lungs such as dirt etc will stay there
What is the first thing viruses infect in the lung?
Ciliated epithelium
Why does a virus infecting the ciliated epithelium disrupt the mucociliary escalator?
It kills the cells it infects
How do bacteria capitalise on the damaged epithelium?
They can then get passed the mucociliary escalator
What condition will the bacteria cause once they get passed the mucociliary escalator?
Pneumonia
What other aspects of defence are there apart from macrophages and the mucociliary membrane?
- Secretions
- The upper resp. tract acts as a filter
How does the upper respiratory tract act as a filter?
- Catches particles
- Has hair and mucus
What is the other function of the upper respiratory besides acting as a filter?
Warming and humidifying the air we breathe to make it easier
What is “the anatomical aspect pneumonia”?
How it looks on an X-ray
What will “the aetiological aspect of pneumonia” help you predict?
The likely organisms involved
What is “the microbiological aspect of pneumonia”?
Exactly what organism is involved
What is community acquired pneumonia?
Pneumonia caught directly from the community.
What other types of pneumonia exist besides community acquired?
- HAI
- Immunocompromised pneumonia
- Atypical
- Aspiration
- Recurrent
What is atypical pneumonia?
- Lack of exudate in the alveoli
- Interstitum gets inflamed
What is aspiration pneumonia?
Occurs when foreign bodies enter the bronchial tree
What is indicated by recurrent pneumonia?
There is something systemically wrong
What are the 5 different patterns of pneumonia?
- Bronchopneumonia
- Segmental/lobar
- Hypostatic
- Aspiration
- Obstruction
What is the pathology of bronchopneumonia?
- Airways filled with pus and inflammatory exudate
- Bacterial
Where in the lungs does the pus and inflammatory exudate of bronchopneumonia get deposited?
- In the parenchyma
- Centrally acinar region
What conditions is bronchopneumonia more common with?
- Cardiac failure
- Chronic bronchitis
How does segmental/lobar pneumonia differ from bronchopneumonia?
- More aggressive organisms
- Inflammatory exudate fills a whole lobe or even the whole lung
What is meant by a hypostatic pneumonia pattern?
Exudate pools at the bottom of the lung due to gravity
If unresolved, what conditions can come about from pneumonia?
- Pleurisy
- Pleural effusion
- Empyema
What is pleural effusion?
Excess fluid in the pleural cavity
What is empyema?
When the pus in the pleural space is converted to fibrous tissue by the body
When would a lung abscess form?
- If lung tissue becomes necrotic
What is bronchiectasis?
When more distal bronchi become dilated (pathology)
What will be a result of the distal bronchi being more dilated?
- Mucociliary elevator will fail
- Pooling
- Infection
