The following steps are involved in muscle contraction: (1) The sequence of events leading to contraction is initiated somewhere in the central nervous system, either as voluntary activity from the brain or as reflex activity from the spinal cord.
The average Mexican man weighs 165 pounds and stands 5 feet 4 1/2 inches tall, while the median figures for Mexican women are 151 pounds and 5 feet 2 inches, according to a study released by a group representing Mexico's clothing industry.
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.