Module 7: Figure lung morphology

Smooth muscle cell (SMC) location in the lung.

A lung slice was stained with an antibody against smooth muscle cell α-actin 9 (green) and the fluorescent image was superimposed on a phase-contrast image to show the ring of smooth muscle cells (SMCs) that surround both the bronchiole airway (A) and an associated arteriole (a). The airway is lined with epithelial cells (EPC) whereas endothelial cells (ENC) line the arterioles. The response of these two vessels to different agonists is shown in Module 7: Figure bronchiole-arteriole contraction. Reproduced from Perez and Sanderson (2005b).