
Venule
The smallest venules, composed simply of an endothelial layer, have wider lumens than do capillaries, although they serve similar functions. Seen here is a venule cut in longitudinal section. Also present are capillaries and an arteriole with a single layer of smooth muscle cells. Surrounding the venule is loose connective tissue with elastic fibers cut in cross section. 1000x

Venule
The smallest venules, composed simply of an endothelial layer, have wider lumens than do capillaries, although they serve similar functions. Seen here is a venule cut in longitudinal section. Also present are capillaries and an arteriole with a single layer of smooth muscle cells. Surrounding the venule is loose connective tissue with elastic fibers cut in cross section. 1000x

- Endothelium
The smallest venules, composed simply of an endothelial layer, have wider lumens than do capillaries, although they serve similar functions. Seen here is a venule cut in longitudinal section. Also present are capillaries and an arteriole with a single layer of smooth muscle cells. Surrounding the venule is loose connective tissue with elastic fibers cut in cross section. 1000x

Capillary
The smallest venules, composed simply of an endothelial layer, have wider lumens than do capillaries, although they serve similar functions. Seen here is a venule cut in longitudinal section. Also present are capillaries and an arteriole with a single layer of smooth muscle cells. Surrounding the venule is loose connective tissue with elastic fibers cut in cross section. 1000x

Arteriole
The smallest venules, composed simply of an endothelial layer, have wider lumens than do capillaries, although they serve similar functions. Seen here is a venule cut in longitudinal section. Also present are capillaries and an arteriole with a single layer of smooth muscle cells. Surrounding the venule is loose connective tissue with elastic fibers cut in cross section. 1000x

Elastic fibers
The smallest venules, composed simply of an endothelial layer, have wider lumens than do capillaries, although they serve similar functions. Seen here is a venule cut in longitudinal section. Also present are capillaries and an arteriole with a single layer of smooth muscle cells. Surrounding the venule is loose connective tissue with elastic fibers cut in cross section. 1000x