14th September 2016
Every minute 750 ml of blood gets pumped through your brain, which is merely 15–20 per cent of blood flow from the heart. An adult brain requires about 20 per cent of the body’s oxygen. To meet this requirement, and other metabolic needs of the neurons, approximately 20 per cent of the blood flow is directed to the brain. Lack of adequate supply of blood to the brain can result in cerebral strokes or haemorrhages.
18th May 2016
During fertilization of the egg by the sperm, the DNA of the sperm is injected into the egg. Both the sperm and the egg have a single set of chromosomes each, but the fertilized egg receives the DNA from the sperm and comes to possess both the sets of chromosomes. This fertilized egg cell stays as such for about half an hour and then proceeds to divide to form the multicellular embryo. Thus, all of us have spent about half an hour as a single cell.
4th May 2016
Chromosomes are considered the basic structures of heredity. They carry the codes that give rise to the expression of the characteristic features of an organism. Humans have 46 chromosomes. In 1997, a team of scientists J.J. Harrington, G.V. Bokkelen, R.W. Mays, K. Gustashaw, and H.F. Willard synthesized artificial chromosomes. These chromosomes are stable up to six weeks. These chromosomes can be used as vectors to carry genes of interest into other cells and for the study of their expression.
21st April 2016
The fastest moving muscle in the human body is the one that closes the eyelid. This muscle is called the orbicularis muscle. The opening or closing of the eye, or the blink of the eye, was used for measuring time in ancient India. The Vedic texts designated the blink of an eye as a nimish. One nimish, according to the modern mathematical calculations, is 0.2133 seconds.
18th February 2016
Human beings have over 600 separate muscles in the body. Tendons connect bones to the muscles. There are three types of muscles, skeletal, smooth and cardiac. Muscles enable movement. We use 43 muscles to frown, 17 muscles to smile, and 54 muscles every time we step forward.
15th February 2016
A virtual model of the brain which is capable of daydreaming just like human beings has been developed by scientists. The computer has been modelled on the dynamics of brain cells and the many connections these cells make with the cells in the brain. This is expected to be useful as a diagnostic tool for the treatment of brain injuries.