(2) A motor neuron in the ventral horn of the spinal cord is activated, and an action potential passes outward in a ventral root of the spinal cord. (3) The axon branches to supply a number of muscle fibers called a motor unit, and the action potential is conveyed to a motor end plate on each muscle fiber.
The average male height varies from country to country. The estimated average height for the human male across the world is approximately 5ft 8 1/2in (1.73 m.) According to John Komlos of the University of Munich, North Americans were the tallest people on the planet from about the American Revolution to World War II.
At age 30, the average height for black men is about 69 inches while for white men it is 70 inches. At age 40 they are both about 69 and a half inches. At age 50, average black men about 69 and average white men about 70 inches. At age 60, black men 68 and a half inches and white men 69 inches.