Artificial organ to become stronger and lighter, limiting the amount of extra energy necessary to operate the limb. Additional materials have allowed artificial limbs to look much more realistic. Prostheses can roughly be categorized as upper- and lower-extremity and can take many shapes and sizes. New advances in artificial limbs include additional levels of integration with the human body. Electrodes can be placed into nervous tissue, and the body can be trained to control the prosthesis. This technology has been used in both animals and humans. The prosthetic can be controlled by the brain using a direct implant or implant into various
Composition of the human body g in men, ~2.3 g in women Of the 94 naturally occurring chemical elements, 60 are listed in the table above. Of the remaining 34, it is not known how many occur in the human body. Most of the elements needed for life are relatively common in the Earth's crust. Aluminium, the third most common element in the Earth's crust (after oxygen and silicon), serves no function in living cells, but is harmful in large amounts. Transferrins can bind aluminium. The composition of the human body is expressed in terms of chemicals: The composition of the human body can be