Astrid Gillich, Ph.D., Postdoctoral Fellow (Krasnow Laboratory) Department of Biochemistry, Stanford University School of Medicine
With every breath we take, oxygen is brought into the body and carbon dioxide is removed. For this transfer to take place efficiently, the blood vessels must lie very close to the air spaces. This close association actually begins very late during embryonic development, at the beginning of the seventh month of gestation in humans. This image shows a developing mouse lung, as both blood vessels and airway epithelium are actively branching and growing together. The fact that this connection between the future airways and the blood vessels develops so late in gestation can be problematic for premature infants. Approximately 80,000 infants are born each year with respiratory failure due to problems with maturity of the lung.