Lung Anatomy & Histology

Alveolar histology

Alveolar Histology

Cells that make up the aveoli.

1)      Type I Pneumocytes – flat sqm cells (alveolar epithelial cells)
2)      Type II – cuboidal cells that do alveolar repair and make surfactant
3)      Macrophage – phagocytic fxn; filled w/golden-brown “smoker’s pigment” in smokers
4)      Pores of Kohn – connect adjacent alveoli, does collateral ventilation
5)      Lambert’s canals – comm. b/w airway and adj alveoli, collateral ventilation
6)      Capillary endothelial cells
7)      Reticular elastic fibers and myofibroblasts

 

Alveolar Epithelial Cells

Alveolar epithelial cells refers to Type I and Type II pneumocytes which make up an alveoli.  Type I cells compose more than 95% and are involved in gas exchange.  Type II cells make surfactant.

Type I Pneumocytes

Type I pneumocytes are flat squamous cells of alveoli that are used for gas exchange.  They cover most (more than 95%) of the surface area of an aveoli.

Lung Anatomy

Lung Anatomy

·        3 right lobes; 2 left lobes + lingula; 10 bronchopulm segments bilat w/i lobes
·        lobule – smallest gross anatomic compartment of lung (3-5 terminal bronchioles, 30 pulm acini)
·        bronchial arteries arise from intercostals and aorta; bronchial veins return to azygos and intercostals veins
·        superficial lymphatics along pleural surface; deep (intrapulm) lymph adj to bronchovasc bundle and along interlob septa; connected