My Science School

In times of war, soldiers use special helmets to protect their heads. While driving a scooter, the riders often wear helmets to protect their heads against any injury. In many cities the governments have even made the helmets compulsory for riders. Do you know why the protection of head is necessary?

The most important part of our body, the brain, is located in the cranium under the protection of bones. The human brain is divided into three main parts: the cerebrum, the cerebellum and medulla oblongata. It controls all the important functions of the body – sight, taste, smell, hearing, touch, movements, memory, speech etc. Any damage to brain can disturb the proper body functioning.

Our brain is protected by the thick bone of the skull. Further a shock absorbing fluid cushions it against the blows of bumps. But if the blow is sharp or hard enough it can injure the skull. Thus to protect the brain from injuries it is essential to first protect the head.

Now the question arises what may be the consequences of head injuries?

A severe head injury due to an accident may cause brain hemorrhage which eventually may lead to death. The injury may damage the memory unit of brain by which a man can loose memory temporarily or permanently. It has been often seen that after having a severe injury of head people remain in coma for long periods.

If the brain tissues are damaged it may give rise to multiple sclerosis. Parkinson’s disease is caused by a disorder of brain chemistry which may result due to head injury. Brain injury may cause aphasia, a serious disorder of thought and communication. Apart from these effects many other disabling conditions can be generated by head injuries.

It is therefore essential to protect the head against injuries.

          More than 60 years back typhoid epidemics used to claim thousands of lives every year. But now, on account of research and advancement in medical science it has been largely controlled.

          Typhoid fever is an acute infectious disease caused by the typhoid bacillus. In medical terminology it is called bacillus salmonella typhosa. It enters the body via contaminated food, water, or milk and finally reaches the blood stream. It infects the blood and poisons the system. Among its main symptoms are fever, cough, headache, skin eruption, enlargement of the spleen, and a fall in the number of white cells. There may also be a loss of appetite. Persistent fever develops which gradually rises, reaching up to 39.4°C or 40°C. After a spell of one or two weeks it starts falling. In about 30 days, the temperature becomes normal.

          Formerly, the treatment was entirely symptomatic and supportive. After 1948 specific treatment with antibiotics was developed which proved to be very effective. Medicines like Chloramphenicol or Tetracyclines provide suitable antibiotic therapy. Cold sponge baths help to control the high fever. In some severe cases, the doctor may even go in for blood transfusion or infuse blood plasma. 

Continue reading "What is typhoid? "

          In fact, crying is the baby’s first sound message. It is the first attempt of the baby to communicate with the world around him. As the baby is unable to put its feelings and desires in words, it communicates by crying!

          It is a matter of common experience that newborn babies cry a lot during the first few months. As the baby starts growing up, there is a marked decline in this practice. By the time the baby is two years old, this habit is almost gone.

          It is interesting to note that this practice doesn’t just express wants and discomforts like hunger or illness. Normally the tears do not appear unless the baby is really distressed. 

          Most mothers are able to distinguish between cries indicating hunger, anger or pain. They are able to tell, with some degree of accuracy what the baby wants. For example, if a baby is hungry, it will continue to cry even when fondled. But if it is crying from boredom, it will stop crying when picked up or when moved to other interesting surroundings.

          Recent studies have shown that if a mother is sensitive in this regard, and responds accordingly, the baby will cry much less by the end of the first year as compared to one who is not. Knowledge of the basic food-stuffs essential to a growing child is necessary to become an ideal mother.

          By the age of four or five months most babies start making certain special sounds. These sounds are called  babblings. It has been observed that babies enjoy these sounds.

          It is not always possible to know why a baby cries. There are occasions when the baby is neither hungry, tired, uncomfortable, bored nor frightened but still keeps on crying. However, usually the baby’s cries are meant to communicate some message.

          When a person falls sick, the doctor often examines his pulse by placing his fingers on the wrist of the patient. What does this pulse indicate?

          By pulse we mean the regular throbbing of arteries caused by the successive contractions of the heart. During the action of the heart there is a pause. During this pause the wall of the aorta contracts. This contraction forces the excess blood to proceed along the arteries. This alternate expansion and contraction of the aorta produces a throbbing in the arteries. This throbbing which can be felt at many points in the body, through the skin, is called pulse.

          The pulse can be felt by placing fingers on the wrist over the radical artery. It can also be felt at the temples where we have temporal artery or at other places where an artery is near the surface. This sensation cannot be felt in the veins because the blood reaches them from the arteries by passing through the narrow capillaries.

          The nurse or a doctor asks the patient to put the arm in a relaxed position with the thumb turned upwards. Then the doctor feels the pulse. The beats are counted for one minute. Since the pulsations mean the heart contraction, the pulse tells us about the heart rate. The pulse rate depends on the blood requirement of the body. This rate indicates how fast the heart is beating and the state of pressure in the circulatory system. An irregular pulse may indicate some abnormality in the functioning of the heart.

          The number of pulsations per minute normally varies from 78 to 82 among women and from 70 to 72 among men. The pulse rate in children is much higher than the healthy adults. The normal rate for a seven-year old child is 90 beats per minute. A new born baby can have a pulse rate of 140. The old people can be in the 50-65 range of pulse rate.