Brain: Girls brains account for 2.5 of their body weight and Boys brain account for 2%. Brain is 80% fluid. The average brain weighs 2.6 pounds; the brain requires 20% of the bodies’ blood supply. There are sixty thousand miles of blood vessels in the human body. Men have decreased fertility rates after age 35
Nerves: Nerve cells create electrical impulses that reach speeds exceeding 270 miles per hour. An adult has over 600,000 sensory receptors in the skin – more nerve endings than any other part of the body. The fingertips are one of the most sensitive areas, with up to 50,000 nerve endings every square inch. The fingertips are so sensitive that a single touch sensor can respond to a pressure of less than 1 / 1400 of a once the weight of an average housefly. To Digest: chew 10-30 times, swallow 4-8 seconds, churn 2-4 hours, absorb 3-5 hours, compact 10 hours and several days, eliminate
Muscle: The single smallest muscle in the human body is located in the middle ear. The stapedius muscle measures less than 1 / 20 of an inch, thinner than a U.S. dime. It activates the stirrup, one of the tiny bones of the ear, which sends vibrations from the eardrum into the inner ear. The stapedius, however, may not be the absolute shortest muscle in the body. A minuscule involuntary muscle called the arrector pili attaches to every hair follicle on the human body. These microscopic muscles nevertheless have a big responsibility: When you are cold or respond to a strong emotion such as fear, the arrector pili muscles raise the hair, producing goose bumps and helping to retain body heat. They are also believed to have given our evolutionary ancestors the hair-raising ability of appearing larger to potential enemies. Humans have only four muscles with which to move the ears. These muscles tend to be weak, and on some of us, they are not even functional. Horses, on the other hand, have thirteen muscles that perform a variety of ear movements. Why? Humans communicate their feelings through fascial expressions and not by wiggling their ears. Horses, however, display their emotions primarily with their ears, so they need a strong, diverse group of muscles to create specific actions and expressions. The muscular system is made up of some six trillion muscle fibers. Each fiber is thinner than a human hair, but can support up to 1000 times its own weight.
Blood Vessels: Although the average adult male is nearly six feet tall, if his arteries, veins, and capillaries were strung together they would stretch for 317 million feet or 60,000 miles.
Intelligence: Aunts and bees, both revered for their intelligence and diligence, have roughly 250 and 900 nerve cells, respectively, in their entire bodies. Humans, who do not always demonstrate such qualities, have an estimated 10,000,000,000 nerve cells in the brain alone.
Bones: There are 206 Bones of the body, 639 named muscles in the human body, the skeleton makes up 15% of the body weight and Bones are 5 times stronger than steal. Thyroid cartilage is sometimes referred to as the Adams Apple. The name derives from a folk legend that told how the biblical Adam’s first bite of apple became stuck halfway down his throat. According to the legend, his male descendants, with their more visibly protruding thyroid cartilage, appear to have carried on his condition. With the progress of evolution, the skulls of more advanced creatures began to have fewer and fewer bones.