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.
A nerve is an enclosed, cable-like bundle of axons (nerve fibers, the long and slender projections of neurons) in the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons to peripheral organs.eurons are sometimes called nerve cells, though this term is potentially misleading since many neurons do not form nerves, and nerves also include non-neuronal Schwann cells that coat the axons in myelin. Each nerve is a cordlike structure that contains many axons.