Lungs 3

Front 1

lungs at 15 week gestational age

Back 1

lung is the pseudoglandular phase

Front 2

lungs at 24 week gestational age

Back 2

- lung is the Cannalicular phase
- Neither narrow diffusion you need nor sufficient surfactant

Front 3

Type 1 alveolar cells

Back 3

- less numerous but line 95% of the alveolar surface w/ their long cytoplasmic extensions
– few organelles, as their main function is a barrier

Front 4

Type 2 alveolar cells

Back 4

- have many organelles, b/c they produce surfactant
- surfactant is in housed in lamellar inclusions
– they have very short extensions and only cover 5%

Front 5

dendritic cells

Back 5

- located in airway epi and in the alveolar walls
– similar to macro’s & mono’s
– process and present Ag’s
– Langerhans cells are specific ones in the lungs, have abnormal, and do eosinophilic granuloma of the lung

Front 6

alveolar macrophages

Back 6

– large, mobile, descendents of mono’s
– lots of granules w/ digestive enzymes to kill foreign material and chemoattractant cytokines

Front 7

IgA in the lung

Back 7

- important in upper tract

Front 8

IgG in the lung

Back 8

- important in lower tract