Which statement best describes the lamina propria in the respiratory tract?

• A. Dense connective tissue
• B. Adipose tissue
• C. Areolar tissue
• D. Reticular tissue

Answer: (C)

The lamina propria in the respiratory tract is loose connective tissue, specifically areolar tissue. Lying directly beneath the epithelium, this layer has a loose, mesh-like arrangement of fibers (collagen and elastic) with a rich ground substance. That loose organization provides flexible support for the epithelium, allows diffusion of nutrients from blood vessels, and houses immune cells and small vessels necessary for mucosal defense and nourishment. Dense connective tissue would be too tightly packed to accommodate elasticity; adipose tissue is dominated by fat cells; reticular tissue forms a specialized scaffold in lymphoid organs. So the lamina propria is best described as areolar tissue.