Written By: Ujjwal Matoliya
1️⃣ Digestive System (पाचन तंत्र)
The digestive system is a group of organs that work together to break down food into simple substances that the body can use for energy, growth, and repair. When we eat food, our body cannot use it directly. It must first be broken into small particles like glucose, vitamins, minerals, and proteins. This process is called digestion.
Digestion starts in the mouth. The teeth chew the food into small pieces, and saliva mixes with it. Saliva contains enzymes that begin breaking down starch into sugar. After chewing, the food becomes soft and is swallowed.
The food then moves into the esophagus (food pipe). It does not simply fall down; instead, muscles push it downward by a process called peristalsis. The food reaches the stomach, where it is mixed with strong digestive juices and acids. These acids kill harmful bacteria and further break down food into a semi-liquid substance called chyme.
Next, the food enters the small intestine, which is the longest part of the digestive system. Here, digestion is completed. The liver and pancreas release juices that help break down fats, proteins, and carbohydrates. The small intestine absorbs nutrients into the bloodstream. These nutrients are carried to all parts of the body.
After nutrients are absorbed, the remaining waste moves into the large intestine. Here, water is absorbed, and the waste becomes solid. Finally, waste is stored in the rectum and removed through the anus.
The digestive system is very important because without it, our body would not get energy. It helps in growth, repair of tissues, and maintaining good health.
2️⃣ Respiratory System (श्वसन तंत्र)
The respiratory system is responsible for breathing. It supplies oxygen to the body and removes carbon dioxide. Oxygen is very important because our cells need it to produce energy.
Breathing begins when air enters through the nose. The nose filters dust and warms the air. The air then passes through the trachea (windpipe), which carries it to the lungs. The trachea divides into two tubes called bronchi, which enter each lung.
The lungs are the main organs of the respiratory system. Inside the lungs are tiny air sacs called alveoli. These air sacs are surrounded by blood vessels. Oxygen from the air passes into the blood, and carbon dioxide from the blood passes into the air sacs. This process is called gas exchange.
The diaphragm, a muscle below the lungs, plays an important role in breathing. When we inhale, the diaphragm moves downward, and the lungs expand. When we exhale, the diaphragm moves upward, and the lungs contract.
The oxygen carried by the blood goes to every cell of the body. Cells use oxygen to release energy from food. At the same time, carbon dioxide is produced as waste. The blood carries carbon dioxide back to the lungs, and we breathe it out.
If the respiratory system does not work properly, the body cannot get enough oxygen. This can cause serious health problems. Therefore, clean air and healthy lungs are very important.
3️⃣ Excretory System (उत्सर्जन तंत्र)
The excretory system removes waste and harmful substances from the body. When our body uses food to produce energy, waste products are formed. These wastes must be removed to keep the body healthy.
The main organs of the excretory system are the kidneys, ureters, urinary bladder, and urethra. The kidneys are two bean-shaped organs located in the lower back. Their main function is to filter blood. They remove waste substances like urea and extra water from the blood.
Inside each kidney are millions of tiny filtering units called nephrons. These nephrons clean the blood and produce urine. The clean blood returns to the body, while waste and extra water form urine.
The urine flows from the kidneys through two thin tubes called ureters into the urinary bladder. The bladder stores urine until it is full. When it becomes full, the urine leaves the body through the urethra.
The excretory system also helps maintain the balance of water and salts in the body. It controls blood pressure and keeps the internal environment stable.
If waste is not removed properly, it can build up in the body and cause illness. Therefore, drinking enough water and keeping kidneys healthy is very important.