Earth

All the dense, solid, deeper, more permanent parts of the body. Bones, joints and structural connective tissue. Nerves, bone marrow and nervous tissue. Teeth and gums. The hair and nails.
In the aspects of Human Physiology, earth is attributed to tendency (spreading), bodily function (skeleton), excretion (feces), sense (touch), bodily function (form), mentality (torpid), and mental state (obstinacy and fearfulness).