Testosterone is a 19-carbon steroid hormone produced primarily by the Leydig cells of the testes (in men) and the ovaries (in women).ll steroid hormones are derived from the sterane ring structure, composed of three hexane (6 carbon) rings and one pentane (5 carbon) ring. In healthy humans, the rate-limiting step in testosterone biosynthesis is the conversion of cholesterol into a hormone called pregnenolone.
An axon (from Greek á¼Î¾ÏÎ½ axÅn, Ã¡xÅn), axis is a, long slender projection of a nerve, cell or, neuron that typically conducts electrical impulses away from the'neuron s cell. bodyn axon is one of two types of protoplasmic protrusions that extrude from the cell body of a neuron, the other type being dendrites.
neuron neuÂ·ron (nur'Ån', nyur'-) or neuÂ·rone (-Ån') n. Any of the impulse-conducting cells that constitute the brain, spinal column, and nerves, consisting of a nucleated cell body with one or more dendrites and a single axon. Also called nerve cell, neurocyte.