Science to save lives

The purpose of science education is to develop observational skills, problem-solving skills, and interest students in the various elements of the environment through inquiry into natural phenomena.



In 1950, the average life expectancy of the world was around 50 years, and in sixty years, that life expectancy has increased by more than 20 years. The improvement in the standard of living of the world's people, the use of preventive medicine, health awareness, and the improvement in the quality of treatment have led to an increase in the average life expectancy of people all over the world.



In 1885, Wilhelm Roentgen discovered a type of high-energy ray that could penetrate the body's muscles and produce images on photographic plates. The nature of this ray was unknown at the time, so it was named X-rays.



Magnetic waves, but their wavelength is several thousand times shorter than our known visible light. Therefore, their energy is also several thousand times higher than ordinary light. Since the wavelength is very short, we cannot see X-rays with the naked eye.

Figure 14.01 shows how X-rays are produced. There are two electrodes on both sides of a glass sphere, one is the cathode and the other is the anode. The cathode is heated by passing electricity through tungsten. Due to the heat, electrons are released from the filament and the anode is positive. Due to the voltage, it rushes towards it. The higher the voltage between the cathode and the anode, the more kinetic energy the electrons will rush towards the anode. In an X-ray tube, this voltage can be close to 100 thousand volts. The electrons rushing from the cathode with great force hit the anode. Due to the impact of these powerful electrons, the electrons in the inner orbit of the anode atom are displaced. Then, one of the electrons in the outer orbit fills that space. The excess energy then comes out as powerful X-rays. The exact wavelength of X-rays that will be emitted depends on the metal used as the anode. Copper is usually used as the anode. X-rays can be used in many ways, below is a list of some of their uses.




1. Dislocated bones, fractures, broken bones, etc. can be easily identified (Figure 14.02).

2. X-rays are used to detect dental cavities and other decay.

3. Intestinal obstruction can be detected by X-ray of the abdomen.

4. The presence of gallstones and kidney stones can be detected by X-body


5. Chest X-rays can be used to diagnose lung diseases such as tuberculosis, pneumonia, and lung cancer.

6. It can kill cancer cells, so X-rays are used for radiotherapy treatment.

Precautions to be taken to avoid unnecessary X-ray radiation from the body.



is adopted. For this reason, when taking an X-ray of a patient, the rest of the body except the part being X-rayed is covered with a lead apron. Unless absolutely necessary, the abdomen or lower abdomen of pregnant women is not X-rayed.

Ultrasonography is used to take pictures of internal organs, muscles, etc., by using very high frequency sound waves and their echoes. Since the frequency of the sound is 1-10 MHz, it is called ultrasonography. Figure 14.03 shows a typical 2D and recently discovered 3D ultrasonography image.

In an ultrasonography machine, a crystal called a transducer is excited with electrical energy to generate high frequency ultrasonic waves. In an ultrasonic machine, these waves are converted into a narrow beam. The transducer is placed on the body where the reflection of the internal organ is required and the beam is inserted into the body, so that the patient does not feel any pain or discomfort. According to the nature of the organ towards which the beam is directed,reflected, absorbed, or transmitted. When the beam hits a density gradient in muscle or blood, a portion of the wave is reflected and returns to the transducer. These echoes are converted into electrical signals and combined to form a total reflection.