Ultrastructural study of lymphatic capillaries in rabbit and human lungs

Eighteen rabbits of both sexes and twelve human lungs were utilized to study juxta-vascular, juxta-alveolar and inter-alveolar septal lymphatic capillaries under light and electron microscope. The juxta-vascular lymphatics were observed around large arteries and veins as plexuses but singly around small vessels. The occurance of juxta alveolar lymphatics, which could be differentiated from blood capillaries was confirmed. Moreover, inter-alveolar septal clefts were seen, which serve as spaces allowing the transport of tissue fluid