SINCE electron microscope techniques have been applied to histology, several workers have confirmed that the blood–air barrier of the lung consists of a capillary endothelium, a basement ...

For example, a capillary is microscopically thin to allow ... Allows diffusion of gases and nutrients from blood into the body cells Wall Thick, muscular Thinner Very thin, one cell thick Lumen ...

For example, a capillary is microscopically thin to allow ... Allows diffusion of gases and nutrients from blood into the body cells Wall Thick, muscular Thinner Very thin, one cell thick Lumen ...

Construction continued up to the Ming dynasty (1368–1644), when the Great Wall became the world's largest military structure. Its historic and strategic importance is matched only by its architectural ...