Transport of a substance from the lumen (cavity) of an organ into one side of a cell and out the other side of the cell into the extracellular fluid is called <u>transcellular transport</u>.
The two routes of transport of substances across the epithelium of the gut are by transcellular method and paracellular method.
Transcellular transport refers to the transport of solutes across a epithelial cell layer through the cells. The best example is the movement of glucose from the intestinal lumen to the extracellular fluid by the epithelial cells. The epithelial cells use the active transport to generate the transcellular transport. Active transport refers to the transport of substances from a region of its lower concentration to a region of its higher concentration against the concentration gradient using cellular energy.
Through experiments and studies
The central nervous system (CNS), which is made up of the brain and the spinal cord, and the peripheral nervous system (PNS), which is comprised of nerves and ganglia (small concentrations of grey matter).
The brain sends messages to the peripheral nerves in the body via the spinal cord, these have control of muscles and internal organs.