Category Zoology

          We know that construction of a huge structure requires thousands of slabs and other material like steel or stones to make it functional. Similarly billions of cells, tiny or long, subtle or sturdy, construct a living being. All the cells in the human body are not alike. They differ greatly according to the tasks that they have to perform. Muscle cells, for instance, are long and have the ability to contract and shorten the muscle. There are two types of muscle. Some work when our brain tells them to perform. For instances, when we pick up a load, our brain sends signals to muscles in our arms. Other muscles work even when we are asleep, for example, our stomach muscles go on churning the food we have consumed. The cells of the skin are mostly quite flat as their task is generally to cover a surface of the body. It acts as a barrier to infection and prevents the body losing water and heat too rapidly. In fact nature has designed cells to carry out every necessary bodily task.

          When many cells of the same or of different types are arranged together they form a tissue. These cells are put together by a substance called matrix. Its function is similar to that of the mortar placed between layers of bricks. The form of a tissue is determined by the nature and amount of the matrix and the type of cells. For example the quantity of matrix in the skin tissues is very small while in bone tissues it is quite large. The matrix is made from calcium phosphate and carbonate and magnesium phosphate and carbonate. They strengthen the bones. Our blood is made up of pale liquid called plasma and millions of cells or corpuscles. The blood cells float in it quite freely.

          Different types of tissues arranged together form an organ which performs a particular task. In the human eye, for example, there are many different tissues, all of which assist in the process of seeing. Though eye is a very small organ of our body, it is very complicated in structure. It is made of different types of tissues. Some organs like liver are much bigger but they are largely composed of a single type of tissue.

          When several organs work together to perform a special and complicated task, they are usually called a system. Digestive, respiratory, excretory etc. are the different systems which perform different tasks. Every system in the body helps each other and provides energy. For example, many of our activities are controlled by different parts of our brain. The hind brain, which consists of medulla oblongata, controls the heart-lings and digestive system.

          All warm blooded animals and human beings have their own system which varies in different degrees in terms of functional behaviours. 

            When we decide to get up early in the morning at a fixed time, we wake up without the help of an alarm or even a watch. Our body in fact does have a regular daily rhythm and this makes us aware of time. We usually sleep for eight hours every night. Depending upon the temperature of the surroundings our body temperature also undergoes a change and so does the speed of our heartbeat.

            Now the question arises, whether these rhythms depend on a sort of built-in-clock or on the daily changes of light and darkness? A famous experiment gave some clues to scientists to find an answer to this question. For several months the researchers lived alone in a cave where they did not even see daylight and had no idea about the time. They camped in tents, with gas heaters, lights, books and even a record player to make life in the cave bearable. Frequently they used a special phone to call the base camp above ground, reporting when they woke up, ate and went to bed.

            In another experiment people lived in specially built underground apartments. They, too, reported regularly to scientists outside.

            Most of the researchers in these experiments slept and wake up regularly on time. Only few lived on irregular schedules.

            On the basis of these experiments, we may conclude that our body has a built-in-clock. In fact the clock does not exist literarily. The most probable answer could be that our body responds involuntarily to a fixed regular time of all actions or even to any conceived time in mind. The actions in response to time may be the results of involuntary body actions or conditioned reflex actions. When the body is accustomed to a particular time for a particular action or become responsive to a pre-set time in mind then it works accordingly in set times. Researchers are going on this subject and it is hoped that someday scientists would be able to find a definite answer to these questions related with built-in-clocks in our bodies.

               Arthritis is the name given to a group of diseases that cause pain in the joints of the body. Arthritis in general, is a disorder of the joints. In fact, the word arthritis is of Greek origin, which means inflammation of a joint. In these diseases the connecting tissues of the joints get inflammed. Sometimes it can even cripple a patient.

               Although arthritis is more common in old age, it can occur to a person of any age. As per the available data the disease attacks twice as many women as men. It is not restricted to human beings only. It may even attack the animals. Today scientists have sufficient evidence to prove that dinosaurs suffered from arthritis. It may be caused by inflammation or infection in the joints.

               Sometimes it is a symptom of another disease. There are various forms of this disease but the exact cause of most kinds of arthritis is not yet known. Some types of arthritis are caused by injuries or by high content of some special chemicals in the body. It may also be caused by the wearing a way of cartilage in old age or by an allergic reaction involving joint tissues.

               A new form of arthritis has been discovered which is believed to be caused by a virus. It spreads among human beings by a bite from an insect, known as tick.

               In this disease joints get swollen and crooked. The patient feels pain and finds it difficult to move. There is no absolute cure for arthritis, although it is usually treated by aspirin-type drugs to reduce pain and swelling. Physiotherapy has also been found very helpful in its treatment. Vigorous massage and transmission of sound waves into the body is also very effective in curing this disabling disease.

               The treatment of arthritis varies according to the stage of the disease in the patient at the time of medical check-up.

               In preliminary stages the treatment is directed towards the relief of symptoms, improvement in general health and performance of some physical exercises. In some kinds of arthritis, diseased joints can be replaced with artificial ones. 

          After taking meals most of us tend to belch. Some people even belch whenever they want to. Do you know why do we belch?

          Every time we swallow food, a little air goes down with it. A muscular valve at the top of our stomach opens to let in whatever we have consumed and then closes quickly. This keeps strong stomach juices from sloshing out.

          Usually, some air is always present in our stomach. A little gas is produced during the digestion of food. Sometimes carbohydrate bubbles in soda water enter the stomach when we drink soda water. It helps to release pressure of gas generated in stomach due to indigestion. When too much of air and gas collects, our brain gets a signal that something should be done. As a result muscles of our stomach tighten up and the valve opens. Thus we get a burp. The noise is produced by the air and the gas vibrating in the pipes that go out of our stomach. Thus we see that belching is a mechanism and a kind of reflex action by which the extra gases collected in the stomach are released. 

          Just as an engine needs fuels like coal, petrol etc. to run, similarly our body also requires fuel which provides us energy to work with. The substances which act as fuel or energy for our body are fats, carbohydrates, proteins etc. — the substances which our food consists of. Whatever food we take it gets burnt with the help of oxygen which we get from in-breathing, thereby releasing energy by breaking into these constituents. This energy thus produced is used in the performance of all of our voluntary and involuntary body functions. For instance, protein is required for growth and tissue repair while vitamins and the minerals are necessary for the proper functioning of various body organs.

          So, we need to supply these substances regularly to our body for its efficient functioning. That is why we take food regularly.

          Out of these substances taken as food our body absorbs and utilizes useful ones and rejects those which are not needed, in the form of waste material. We excrete daily about 2 kg of urine and stool. Carbon-dioxide also comes out during out-breathing as a waste material. About 400 gm of water comes out through the process of sweating and out-breathing.

          Human body temperature remains constant between 98°F and 99°F. This is a wonderful equilibrium between the production and consumption of heat in the body so that the body temperature remains constant. Food is measured in units of energy, called Calories.

          Our body is a wonderful machine which works continuously without any break. Even when we are in sleep many processes such as respiration, digestion, heart beating etc. go on incessantly. These processes also consume fuel continuously.