= [ system 1 + system 2 + system 3 and so on ]

= [ part 1 + part 2 + part 3 ]

= [ General parts + peculiar parts ]

General parts = [ aerial part + liquid parts + solid parts ]

= [ region 1 + region 2 + region …. region-N]

System 1 = CVS = + blood vessels

Blood vessels = arteries + veins + capillaries

= ( atria + ventricles ) ( left + right )

System 2 = nervous system

NS = CNS + PNS

CNS = + spinal cord

PNS = spinal nerves +

Parts

natural elements

natural elements +

being in

oxygen

carbondioxide

in blood

Energy + + organic matter