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.
Noun. 1. axon-long nerve fiber that conducts away from the cell body of the neuron. axone. nerve fiber, nerve fibre-a threadlike extension of a nerve cell.nerve cell, neuron-a cell that is specialized to conduct nerve impulses.nerve end, nerve ending-the terminal structure of an axon that does not end at a synapse.. axon-long nerve fiber that conducts away from the cell body of the neuron. axone. nerve fiber, nerve fibre-a threadlike extension of a nerve cell. nerve cell, neuron-a cell that is specialized to conduct nerve impulses. nerve end, nerve ending-the terminal structure of an axon that does not end at a synapse.