In our daily life, we use many different types of devices. To travel we use cars, to preserve the food we keep them in the refrigerator, for comfort on hot days we turn on the electric fan, to learn news we watch the television, etc. This list is very long and for that reason, we can understand what a machine or device means. We know that the human body cannot be called a machine. A complete human being is created from just a single cell. There is no machine in this world that starts from a small unit and then transforms into a complete machine on its own. If any malfunction arises within the body, an automatic repair mechanism gets initiated, but no machine can do such a thing. But, still, to compare with the known world or to describe the functions of the different organs of the body, we often compare the human body with machines.
For example, it can be said that our heart is an automatic pump that circulates blood spontaneously without any external stimulation. Our kidney is a filter that removes nitrogenous waste from the blood and thus purifies it. The bones and muscles of the bodywork as mechanical levers and our eyes are in many ways acts like a camera. Not only this, but the human body is made up of small parts or organs just like a complex machine, and each organ performs a definite task. If any organ suffers a malfunction then the whole body's work faces obstruction. So, it can be said that the human body is like an organic machine.
We need the energy to do work with the help of machines. In different engines petrol, diesel, gas, etc. Are used as fuel to transform chemical energy into mechanical energy. Similarly, by eating food and through respiration, we obtain energy for our body from the nutrition of food.
In this way, we can find many similarities between the human body and machines, but we have to remember that the human body is far more amazing, far more surprising, and far more mysterious than the most complex machine of the world. We have not been able to solve completely even a small fraction of that mystery.