Sem 1 - Resp Flashcards
describe resp epithelium (4)
pseudostratified, ciliated, columnar with goblet cells
key feature in distinguishing b/w chron interstitial lung disease and chronic obstructive pulmonary disease?
fibrosis of inter-alveolar septae
what features indicate a bronchiole rather than a blood vessel, alveolus or bronchus?
The structure has a lumen and is lined by ciliated simple columnar epithelium (pseudostratified columnar also accepted - it’s a bit hard to tell in places), thus is not a blood vessel or alveolus.
There is smooth muscle in the wall but no cartilage or seromucinous glands, thus it is not a bronchus.
describe the pleura histologically
simple squamous epithelium (mesothelium) with underlying connective tissue, predominantly collagen.
A 56-year-old man presented to his general practitioner with a 24-48 hour history of fever, increasing shortness of breath, a cough productive of greeny yellow sputum and chest pain in his left lower chest at the back that was worse on deep inspiration..
What abnormality is likely to be found on percussion of the affected lung on clinical examination? why?
What is likely to be seen on the visceral pleura of the left lower lobe?
dullness due to the fluid.
fibrinous exudate in lower left lobe
in the above case what would you expect to see microscopically?
the alveoli filled with acute inflammatory exudate, consisting of fluid, neutrophils and fibrin. There are also many macrophages present. Blood vessels are dilated and congested with blood.
Explain, including relevant cytokines, process of neutrophilia
macrophages release IL-1, IL-6 and TNF> bone marrow to release some of its reserve pool of neutrophils.
In more severe and prolonged acute inflammatory responses it may also increase its production of neutrophils.
Explain how the pattern of infection develops for each of lobar and bronchopneumonia?
In bronchopneumonia the bacteria infect bronchi and bronchioles in a patchy distribution and spread down to the related alveoli where they also induce inflammation. Alveolar involvement is thus patchy. In lobar pneumonia they directly infect the alveoli and spread from alveolus to alveolus by the pores of Kohn.
In Bacterial pneumonia, especially bronchopneumonia (excluding TB) how may death occur? (2) What are other potential issues (3)?
death from hypoxaemia or septicaemia.
other complications include empyema, abscess formation, dissemination of bacteria to other organs.
dif b/w empyema and abcess?
empyema is a collection of pus in a naturally existing anatomical cavity.
Abscess is a collection of pus in a newly formed cavity
black pigment in lung hilum. What is the black pigment likely to be? Is it intracellular or extracellular? Is it predominantly in alveolar spaces or interstitial tissues? Where does much of this pigment end up and by what path does it get there?
The pigment is likely to be carbon and is intracellular (in macrophages). It is predominantly in interstitial tissues. Much of the pigment ends up, having been carried by macrophages in the lymphatics, in the hilar lymph nodes. The carbon is inhaled from pollution and cigarette smoke
Are the microscopic features in TB the same as you would expect in a pneumonia caused by e.g. Strep. pneumoniae or Staph. aureus? If not, outline how they differ.
TB the features are of chronic granulomatous inflammation with epithelioid macrophages, giant cells and lymphocytes. Most pneumonias are caused by organisms that promote an acute inflammatory response i.e. with neutrophils predominating.
explain the route by which the miliary pattern of tuberculous infection develops
Miliary tuberculosis arises following dissemination of bacteria into lungs and/or other organs via the blood stream. Numerous tiny foci of infection develop.
4 clinical features of both chronic TB and acture pneumonia.
fever, cough, sputum production, dyspnea.
3 clinical features of chronic TB that not likely to be present in acute pneumonia
weight loss, night sweats, haemoptysis
