We all know that a normal person will have 5 basic senses: sight (seeing), smell (smelling), hearing (hearing), touch (touching) and taste (tasting). These are called 'extended' senses because they provide us with information about the outside world. However, did you know that each person's body also has organs, or "receptors" to feel what is happening inside the body, such as to recognize the heartbeat, the level of lung expansion, how the stomach is working and many other activities of the internal organs that we are completely unaware of. These activities are called "interoception" - meaning the feeling of the internal state of the body. Our body has receptors to receive all kinds of information about the actual state that the body is going through, for example, changes in body temperature.

In addition, some receptors on certain parts of the body operate more thoroughly than usual to help our bodies adjust and adapt to the living environment. For example, the retina is where the eyes receive and analyze light waves to see, but there are also some other retinal cells that are responsible for “informing” the brain when it is day or night. This “day/night feeling” is the basis for influencing the biological rhythm and metabolism inside our body.

Even the five basic senses, such as vision, are closely linked to other senses. For example, what we see and how we see are related to the process of the brain “monitoring” our heartbeat. When the heart contracts and pumps blood into the arteries, the brain receives less visual information from the outside world than usual. The brain also helps create other special sensory receptors. For example, to perceive a certain flavor, the brain creates information from data collected from taste, smell, and humidity (which is generated from touch and ambient temperature).

In fact, our brain creates everything we see, hear, smell, taste, and feel… using all the other data and information available to us, not just our body’s sensory organs. For example, our brain actually predicts what we might see before we see it, based on past experiences and data, the state of our body, and our current situation. The brain combines these predictions with data coming from vision to build our visual experience of the world around us.

So, in addition to the 5 basic senses, we also have other sensory organs that exist right inside the body so that the body can adjust and operate in the best way, ensuring that we will have the most beneficial state of existence in all situations.