Human Body

Human Body

Human Body

Introduction

The human body is the entire structure of a human organism, and consists of a head, neck, torso, two arms and two legs. By the time the human reaches adulthood, the body consists of close to 10 trillion cells, the basic unit of life (Aristotle, 2005). These cells are organized biologically to eventually form the whole body.

Discussion

One scientist friend told me he thought the human body was nature's supreme achievement. This supreme achievement is something that many of us take for granted. Our everyday activities, however, are powered by a system that is very complex and efficient (Boston Women's Health Book Collective, 2005). Medical science has documented some astonishing facts about our bodies (Aristotle, 2005).

Take the circulatory system. Every minute of our lives the heart pumps 10 pints of blood30 pints during brisk exercise through about 60,000 miles of arteries, veins, and capillaries. An adult body contains between 8 and 10 pints of blood: the average for a man is about 10 pints, containing 25 trillion red cells (to carry oxygen) and 25 billion white cells (to fight disease). Some white cells have a life cycle of only 12 hours, while red cells have a life of about 120 days (Aristotle, 2005). One part of the body that needs blood all the time is the lungs. Their capillaries continuously take up oxygen from the tiny air sacs of the lungs, while releasing excess carbon dioxide. During an average lifetime, we breathe more than 500 million times (Boston Women's Health Book Collective, 2005).

A common saying is that blood is thicker than water (Carlino, 1999). But, in fact, almost two-thirds of the body is water10 gallons of it, or 60 percent of the average person's weight (Aristotle, 2005). Many people think that water retention is responsible for being overweight, but actually, fatty tissue contains only 10 percent water (Boston Women's Health Book Collective, 2005).

The human body also contains an odd assortment of other substances: enough lime to whitewash a small shed, the carbon equivalent of a 28-pound bag of coke, enough fat for seven cakes of soap, and enough phosphorus to make 2,200 matches (Boston Women's Health Book Collective, 2005).

A baby is born with 305 bones, but some of these fuse together later until there are about 206 (though the number can vary), operated by 650 muscles and more than 100 joints(Carlino, 1999). The tendons anchoring muscle to bone ...