Many body functions are orchestrated through the nervous system. Nerves function as a result of electrical chemical processes. Touch influences these processes in ways that at present, are only partially explained by modern science.
The nervous system is composed of the central nervous system and the peripheral nervous system. The central nervous system includes the brain and spine and receives and sends signals with the peripheral nervous system. Peripheral nervous system runs the body - peripheral nerves can be found in every organ, gland, brain, and tissue over the entire length and breadth of the body. The number of sensory fibers from the skin entering the spinal cord by the posterior roots is well over half a million.
Touch creates chemical and electrical signals that travel the branches and pathways of nerves starting from the surface of the body to many locations, including brain, organs, glands, etc. Many of the electrical and chemical mechanisms have been identified. dozens of large molecules convey information from cell to cell and within cells. Proteins created from touch guide nerves to make connection with other nerves.