Blood usually passes through one network of capillaries from the time it leaves the heart until the time it returns, but there are exceptions, notably the .

the tricuspid valve is present between right atrium and right ventricle

the elements of art are the visual tools that the artist uses to create a composition. these are line, shape, color, value, form, texture, and space.

the principles of art and design are balance, contrast, emphasis, movement, pattern, rhythm, and unity/variety.