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 neuron is a nerve cell in which, are circular cells that are bundled together known as ganglion. A actual nerve is attached to the nerve cell. There are two types of nerves â¦ ones that travel messages from the brain or to the brain.A nerve fiber that sends messages from the brain is called an axon fiber.The structure of an axon fiber includes myelin, which is a fatty substance stored on the outside of the nerve fiber to speed the message up. between each piece of myelin is a space called the node of ranvier that speeds the impulse up to. neuron is a nerve cell in which, are circular cells that are bundled together known as ganglion. A actual nerve is attached to the nerve cell. There are two types of nerves â¦ ones that travel messages from the brain or to the brain.