WONDERS OF HUMAN BODY

WONDERS OF HUMAN BODY

     There are many wonders in the design of human body. We can think of a few wonders only, as they are unlimited. One should know at least something about his own body. Hence this post is written. Importance is given not for the functions of body or bodily diseases but for certain aspects connected to body that lends a note of mystery to our mind. 

     Right with the start of formation in the womb, the human body is only a speck, but it develops into more than 5 billion times by the time it grows into full shape. Average interval time between the time of birth and fertilization of egg is about 266 days. Most cells die at the rate of about 5 millions per second and the heart beats about 40 million times every year. A human blinks about 6 million times every year. Brain needs more blood, about 20% of the total blood, though its weight is only 2% of the total body weight. Bones and joints can be replaced by stainless steel and titanium. But the latest development shows that even heart and liver can also be replaced.

     The life span of red blood cells is about 3 months only whereas the life of nerve cells in the brain is more than 50 years. About 2 million red cells are being created every second by the bone morrow. Experiments are being made to know whether change of blood of aged people with blood of young can increase the health and also life span among the old people. It is successful in case of mice. If this happens number of aged will be more than the number of new born and children. However the average life span of human beings is likely to be increased to 150 years shortly with the latest discoveries in medical field. Science has developed to such a stage that a man can be turned into a woman and a woman can be changed into a man. It is successful practically.

     The surface of the skin is made up with tiny dead cell flakes not visible to the naked eye that can be rubbed away. Body looses about 4 kg.  of rubbed  skin flakes every year. Hair on head grows for about 5 years up to a length of about one metre and rarely up to four metres also before it falls naturally. Number of hair on the head (scalp) is more if its color is light and less if it is black. Hair in the head grows at the rate of 3.5 mm per week. Hair colour is dependent on the genes from parents. On the average there are about 120000 hairs on the head. Nails grow about half a millimetre per week.

     There are about 650 muscles and 206 bones in an adult body, but the numbers of bones in a baby are about 306. Some of this join together and become one as the baby grows. The largest bone in the body is thigh bone while the smallest is the stirrup bone in the ear. The skull has 22 separate bones bound together by fibres.  Spine supports the body mainly. It is made up of 22 vertebrae. Spine also supports spinal cord which connects the brain to all body parts. The body has more than 200 joints, the largest being at hip and knees. The biggest muscle is also in the hips.

     Heart pumps about 200 million litres of blood in an average life time. Adults’ heartbeat rate at rest is around 72 per minute. For a new baby it is around 125 per minute. One cubic mm of blood contains about 5 million red cells, 8000 white cells and 350000 platelets. The volume of blood in a man is about 5.5 litres and of a  women is about 4.5 litres. There are mainly four blood groups, namely A O B AB. O is popular. Each group is either Rh.+ or Rh.-. For the patients requiring blood transfusion same group of blood should be given. Otherwise they can become very ill.

     One can urinate about 45000 litres in his life time. Body’s water balance is controlled by urinary system. In each kidney there are about one million tiny filters known as nephrons. Kidneys take about 85 litres of water and other substances from blood of 1000 litres and let out only 0.6 litre of urine after recycling.

     Nervous system controls organs and tissues in the body. The total length of nervous system in the body is about 80000 k m. The fastest nerve signals travel at a speed of 120 m per second and the slowest is about 1.5 m per second. A network of nerves connects brain to every bodily part. The brain is the first part and biggest at one stage to be developed in the womb. The human brain is about 1/50^th of the weight of the human body and has a much greater proportion compared to other animals. That is the reason perhaps that the human being is so intelligent among the living beings.

     Respiratory system takes air and separates oxygen from it, pass it into blood. Body cells take this oxygen to burn glucose, which also cells receive from blood when it carries digested food. Under normal rest one can once breathe half litre of air in about 4 seconds. Strenuous breathing rate may be more than 60 breathes per minute. New born babies may breathe up to 40 times a minute.  For an aged person of 80 years the total number of breathes in his life time may be around 600 millions. Oxygen rich blood from the lungs that goes to the heart is red while the blood that comes to lungs is poor in oxygen and its color is dull purple.

     The total quantity of food one can eat in one year is about 10 times his body weight. While passing through the tract, the food is broken to small substances known as nutrients and get absorbed into the blood. The whole journey of food from mouth to anus takes about 24 hours. The length of the digestive system is about 9 metres.    

     Dogs’ nose is 10000 times more sensitive to smell than a human being. Leprosy destroys nerves that respond to touch. Hence a leprosy patient can suffer injuries without realizing it. Tongue has a unique print just like finger print. Tooth is the only unrepairable part of the body. Our body consists of about 50 million cells and each cell has its genetic code that makes us as a unique individual. The genetic code is found in DNA.