According to Buddhist/Hindu teaching all of the chakras contribute to a human's well-being. Our instincts would join forces with our feelings and thinking. Some of our chakras are usually not open all the way but some are over-active, or even near closed. If the chakras are not balanced, peace with the self cannot be achieved.
Chakra is a Sanskrit word, which translates to "wheel," or "vortex," and that's what it looks like when we look at a chakra. Each chakra is like a solid ball of energy interpenetrating the physical body, in the same way that a magnetic field can interpenetrate the physical body. The chakras are not physical; they are an aspects of consciousness* in the same way that the auras are aspects of consciousness. However, chakras are denser than the auras, but not as dense as the physical body. They interact with the physical body through two ways, the endocrine system and the nervous system. Each of the chakras is associated with one of the endocrine glands, and also with a particular group of nerves called a plexus. So each chakra can be associated with particular parts of the body and particular functions within the body controlled by that plexus or that endocrine gland associated with that chakra.
There are seven main chakras in the human body and eight within the horse, dog and cat body.
Your consciousness, your experience of being, represents everything that is possible for you to experience. All of your senses, all of your perceptions, all of your possible states of awareness, can be divided into categories, and each of these categories can be associated with a particular chakra. Each chakra represents not only particular parts of your physical body, but also particular parts of your consciousness.
When you feel tension in your consciousness, you feel it in the chakra associated with the part of your consciousness experiencing the stress, and in the parts of the physical body associated with that chakra. Where you feel the stress depends therefore on why you feel the stress. When someone is hurt in a relationship, they feel it in their heart. When someone is nervous, their legs tremble and their bladder becomes weak.
When there is tension in a particular part of your consciousness, and therefore in the chakra associated with that part of your consciousness, the tension is detected by the nerves of the plexus associated with that chakra, and communicated to the parts of the body controlled by that plexus. When the tension continues over a period of time, or reaches a particular degree of intensity, the person creates a symptom on the physical level. Again, the symptom served to communicate to the person through their body what they had been doing to themselves in their consciousness. When the person changes something about their way of being, they are able to release the stress that had been creating the symptom, and they are then able to return to their natural state of balance and health.
*consciousness: Your consciousness is who you are, your experience of Being, "Life Energy". This energy does not just live in your brain; it fills your entire body on all levels.