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 1/50th 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.